| Message ID | 20211215021348.8766-1-kernelfans@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [PATCHv3] efi: apply memblock cap after memblock_add() | expand |
On 2021/12/15 10:13, Pingfan Liu wrote: > On arm64, during kdump kernel saves vmcore, it runs into the following bug: > ... > [ 15.148919] usercopy: Kernel memory exposure attempt detected from SLUB object 'kmem_cache_node' (offset 0, size 4096)! > [ 15.159707] ------------[ cut here ]------------ > [ 15.164311] kernel BUG at mm/usercopy.c:99! > [ 15.168482] Internal error: Oops - BUG: 0 [#1] SMP > [ 15.173261] Modules linked in: xfs libcrc32c crct10dif_ce ghash_ce sha2_ce sha256_arm64 sha1_ce sbsa_gwdt ast i2c_algo_bit drm_vram_helper drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops cec drm_ttm_helper ttm drm nvme nvme_core xgene_hwmon i2c_designware_platform i2c_designware_core dm_mirror dm_region_hash dm_log dm_mod overlay squashfs zstd_decompress loop > [ 15.206186] CPU: 0 PID: 542 Comm: cp Not tainted 5.16.0-rc4 #1 > [ 15.212006] Hardware name: GIGABYTE R272-P30-JG/MP32-AR0-JG, BIOS F12 (SCP: 1.5.20210426) 05/13/2021 > [ 15.221125] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) > [ 15.228073] pc : usercopy_abort+0x9c/0xa0 > [ 15.232074] lr : usercopy_abort+0x9c/0xa0 > [ 15.236070] sp : ffff8000121abba0 > [ 15.239371] x29: ffff8000121abbb0 x28: 0000000000003000 x27: 0000000000000000 > [ 15.246494] x26: 0000000080000400 x25: 0000ffff885c7000 x24: 0000000000000000 > [ 15.253617] x23: 000007ff80400000 x22: ffff07ff80401000 x21: 0000000000000001 > [ 15.260739] x20: 0000000000001000 x19: ffff07ff80400000 x18: ffffffffffffffff > [ 15.267861] x17: 656a626f2042554c x16: 53206d6f72662064 x15: 6574636574656420 > [ 15.274983] x14: 74706d6574746120 x13: 2129363930342065 x12: 7a6973202c302074 > [ 15.282105] x11: ffffc8b041d1b148 x10: 00000000ffff8000 x9 : ffffc8b04012812c > [ 15.289228] x8 : 00000000ffff7fff x7 : ffffc8b041d1b148 x6 : 0000000000000000 > [ 15.296349] x5 : 0000000000000000 x4 : 0000000000007fff x3 : 0000000000000000 > [ 15.303471] x2 : 0000000000000000 x1 : ffff07ff8c064800 x0 : 000000000000006b > [ 15.310593] Call trace: > [ 15.313027] usercopy_abort+0x9c/0xa0 > [ 15.316677] __check_heap_object+0xd4/0xf0 > [ 15.320762] __check_object_size.part.0+0x160/0x1e0 > [ 15.325628] __check_object_size+0x2c/0x40 > [ 15.329711] copy_oldmem_page+0x7c/0x140 > [ 15.333623] read_from_oldmem.part.0+0xfc/0x1c0 > [ 15.338142] __read_vmcore.constprop.0+0x23c/0x350 > [ 15.342920] read_vmcore+0x28/0x34 > [ 15.346309] proc_reg_read+0xb4/0xf0 > [ 15.349871] vfs_read+0xb8/0x1f0 > [ 15.353088] ksys_read+0x74/0x100 > [ 15.356390] __arm64_sys_read+0x28/0x34 > ... > > This bug introduced by commit b261dba2fdb2 ("arm64: kdump: Remove custom > linux,usable-memory-range handling"), which moves > memblock_cap_memory_range() to fdt, but it breaches the rules that > memblock_cap_memory_range() should come after memblock_add() etc as said > in commit e888fa7bb882 ("memblock: Check memory add/cap ordering"). void __init early_init_dt_scan_nodes(void) { //(1) -->early_init_dt_check_for_usable_mem_range, fill cap_mem_addr rc = of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line); //(2) --> early_init_dt_add_memory_arch --> memblock_add() of_scan_flat_dt(early_init_dt_scan_memory, NULL); //(3) memblock_cap_memory_range(cap_mem_addr, cap_mem_size); } I didn't get it. The above step (1),(2),(3) comply with commit e888fa7bb882 ("memblock: Check memory add/cap ordering") Did you see the warning? pr_warn("%s: No memory registered yet\n", __func__); > > As a consequence, the virtual address set up by copy_oldmem_page() does > not bail out from the test of virt_addr_valid() in check_heap_object(), > and finally hits the BUG_ON(). > > Since memblock allocator has no idea about when the memblock is fully > populated, while efi_init() is aware, so tackling this issue by calling the > interface early_init_dt_check_for_usable_mem_range() exposed by of/fdt. > > Fixes: b261dba2fdb2 ("arm64: kdump: Remove custom linux,usable-memory-range handling") > Signed-off-by: Pingfan Liu <kernelfans@gmail.com> > Cc: Rob Herring <robh+dt@kernel.org> > Cc: Zhen Lei <thunder.leizhen@huawei.com> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Will Deacon <will@kernel.org> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Mike Rapoport <rppt@kernel.org> > Cc: Geert Uytterhoeven <geert+renesas@glider.be> > Cc: Frank Rowand <frowand.list@gmail.com> > Cc: Ard Biesheuvel <ardb@kernel.org> > Cc: Nick Terrell <terrelln@fb.com> > Cc: linux-arm-kernel@lists.infradead.org > To: devicetree@vger.kernel.org > To: linux-efi@vger.kernel.org > --- > v2 -> v3: > use static inline stub to avoid #ifdef according to Rob's suggestion > > drivers/firmware/efi/efi-init.c | 5 +++++ > drivers/of/fdt.c | 2 +- > include/linux/of_fdt.h | 2 ++ > 3 files changed, 8 insertions(+), 1 deletion(-) > > diff --git a/drivers/firmware/efi/efi-init.c b/drivers/firmware/efi/efi-init.c > index b19ce1a83f91..b2c829e95bd1 100644 > --- a/drivers/firmware/efi/efi-init.c > +++ b/drivers/firmware/efi/efi-init.c > @@ -235,6 +235,11 @@ void __init efi_init(void) > } > > reserve_regions(); > + /* > + * For memblock manipulation, the cap should come after the memblock_add(). > + * And now, memblock is fully populated, it is time to do capping. > + */ > + early_init_dt_check_for_usable_mem_range(); > efi_esrt_init(); > efi_mokvar_table_init(); > > diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c > index 18a2df431bfd..aa07ef5cab5f 100644 > --- a/drivers/of/fdt.c > +++ b/drivers/of/fdt.c > @@ -972,7 +972,7 @@ static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND; > * location from flat tree > * @node: reference to node containing usable memory range location ('chosen') > */ > -static void __init early_init_dt_check_for_usable_mem_range(void) > +void __init early_init_dt_check_for_usable_mem_range(void) > { > const __be32 *prop; > int len; > diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h > index cf48983d3c86..ad09beb6d13c 100644 > --- a/include/linux/of_fdt.h > +++ b/include/linux/of_fdt.h > @@ -62,6 +62,7 @@ extern int early_init_dt_scan_chosen(unsigned long node, const char *uname, > int depth, void *data); > extern int early_init_dt_scan_memory(unsigned long node, const char *uname, > int depth, void *data); > +extern void early_init_dt_check_for_usable_mem_range(void); > extern int early_init_dt_scan_chosen_stdout(void); > extern void early_init_fdt_scan_reserved_mem(void); > extern void early_init_fdt_reserve_self(void); > @@ -86,6 +87,7 @@ extern void unflatten_and_copy_device_tree(void); > extern void early_init_devtree(void *); > extern void early_get_first_memblock_info(void *, phys_addr_t *); > #else /* CONFIG_OF_EARLY_FLATTREE */ > +static inline void early_init_dt_check_for_usable_mem_range(void) {} > static inline int early_init_dt_scan_chosen_stdout(void) { return -ENODEV; } > static inline void early_init_fdt_scan_reserved_mem(void) {} > static inline void early_init_fdt_reserve_self(void) {} >
On Wed, Dec 15, 2021 at 11:58:03AM +0800, Leizhen (ThunderTown) wrote: > > > On 2021/12/15 10:13, Pingfan Liu wrote: > > On arm64, during kdump kernel saves vmcore, it runs into the following bug: > > ... > > [ 15.148919] usercopy: Kernel memory exposure attempt detected from SLUB object 'kmem_cache_node' (offset 0, size 4096)! > > [ 15.159707] ------------[ cut here ]------------ > > [ 15.164311] kernel BUG at mm/usercopy.c:99! > > [ 15.168482] Internal error: Oops - BUG: 0 [#1] SMP > > [ 15.173261] Modules linked in: xfs libcrc32c crct10dif_ce ghash_ce sha2_ce sha256_arm64 sha1_ce sbsa_gwdt ast i2c_algo_bit drm_vram_helper drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops cec drm_ttm_helper ttm drm nvme nvme_core xgene_hwmon i2c_designware_platform i2c_designware_core dm_mirror dm_region_hash dm_log dm_mod overlay squashfs zstd_decompress loop > > [ 15.206186] CPU: 0 PID: 542 Comm: cp Not tainted 5.16.0-rc4 #1 > > [ 15.212006] Hardware name: GIGABYTE R272-P30-JG/MP32-AR0-JG, BIOS F12 (SCP: 1.5.20210426) 05/13/2021 > > [ 15.221125] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) > > [ 15.228073] pc : usercopy_abort+0x9c/0xa0 > > [ 15.232074] lr : usercopy_abort+0x9c/0xa0 > > [ 15.236070] sp : ffff8000121abba0 > > [ 15.239371] x29: ffff8000121abbb0 x28: 0000000000003000 x27: 0000000000000000 > > [ 15.246494] x26: 0000000080000400 x25: 0000ffff885c7000 x24: 0000000000000000 > > [ 15.253617] x23: 000007ff80400000 x22: ffff07ff80401000 x21: 0000000000000001 > > [ 15.260739] x20: 0000000000001000 x19: ffff07ff80400000 x18: ffffffffffffffff > > [ 15.267861] x17: 656a626f2042554c x16: 53206d6f72662064 x15: 6574636574656420 > > [ 15.274983] x14: 74706d6574746120 x13: 2129363930342065 x12: 7a6973202c302074 > > [ 15.282105] x11: ffffc8b041d1b148 x10: 00000000ffff8000 x9 : ffffc8b04012812c > > [ 15.289228] x8 : 00000000ffff7fff x7 : ffffc8b041d1b148 x6 : 0000000000000000 > > [ 15.296349] x5 : 0000000000000000 x4 : 0000000000007fff x3 : 0000000000000000 > > [ 15.303471] x2 : 0000000000000000 x1 : ffff07ff8c064800 x0 : 000000000000006b > > [ 15.310593] Call trace: > > [ 15.313027] usercopy_abort+0x9c/0xa0 > > [ 15.316677] __check_heap_object+0xd4/0xf0 > > [ 15.320762] __check_object_size.part.0+0x160/0x1e0 > > [ 15.325628] __check_object_size+0x2c/0x40 > > [ 15.329711] copy_oldmem_page+0x7c/0x140 > > [ 15.333623] read_from_oldmem.part.0+0xfc/0x1c0 > > [ 15.338142] __read_vmcore.constprop.0+0x23c/0x350 > > [ 15.342920] read_vmcore+0x28/0x34 > > [ 15.346309] proc_reg_read+0xb4/0xf0 > > [ 15.349871] vfs_read+0xb8/0x1f0 > > [ 15.353088] ksys_read+0x74/0x100 > > [ 15.356390] __arm64_sys_read+0x28/0x34 > > ... > > > > This bug introduced by commit b261dba2fdb2 ("arm64: kdump: Remove custom > > linux,usable-memory-range handling"), which moves > > memblock_cap_memory_range() to fdt, but it breaches the rules that > > memblock_cap_memory_range() should come after memblock_add() etc as said > > in commit e888fa7bb882 ("memblock: Check memory add/cap ordering"). > > void __init early_init_dt_scan_nodes(void) > { > //(1) -->early_init_dt_check_for_usable_mem_range, fill cap_mem_addr > rc = of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line); > > //(2) --> early_init_dt_add_memory_arch --> memblock_add() > of_scan_flat_dt(early_init_dt_scan_memory, NULL); > > //(3) > memblock_cap_memory_range(cap_mem_addr, cap_mem_size); > } > > I didn't get it. The above step (1),(2),(3) comply with > commit e888fa7bb882 ("memblock: Check memory add/cap ordering") > Well, at this scope, it does. But from a larger scope, let's say on arm64, setup_arch ... setup_machine_fdt(); //which holds your case ... efi_init(); //which call memblock_add, and breach the ordering. > Did you see the warning? > pr_warn("%s: No memory registered yet\n", __func__); > Yes, I did see this message, which brings me to commit e888fa7bb882 ("memblock: Check memory add/cap ordering") I am also curious why this bug does not be discovered. Is CONFIG_EFI on at your case? Thanks, Pingfan > > > > As a consequence, the virtual address set up by copy_oldmem_page() does > > not bail out from the test of virt_addr_valid() in check_heap_object(), > > and finally hits the BUG_ON(). > > > > Since memblock allocator has no idea about when the memblock is fully > > populated, while efi_init() is aware, so tackling this issue by calling the > > interface early_init_dt_check_for_usable_mem_range() exposed by of/fdt. > > > > Fixes: b261dba2fdb2 ("arm64: kdump: Remove custom linux,usable-memory-range handling") > > Signed-off-by: Pingfan Liu <kernelfans@gmail.com> > > Cc: Rob Herring <robh+dt@kernel.org> > > Cc: Zhen Lei <thunder.leizhen@huawei.com> > > Cc: Catalin Marinas <catalin.marinas@arm.com> > > Cc: Will Deacon <will@kernel.org> > > Cc: Andrew Morton <akpm@linux-foundation.org> > > Cc: Mike Rapoport <rppt@kernel.org> > > Cc: Geert Uytterhoeven <geert+renesas@glider.be> > > Cc: Frank Rowand <frowand.list@gmail.com> > > Cc: Ard Biesheuvel <ardb@kernel.org> > > Cc: Nick Terrell <terrelln@fb.com> > > Cc: linux-arm-kernel@lists.infradead.org > > To: devicetree@vger.kernel.org > > To: linux-efi@vger.kernel.org > > --- > > v2 -> v3: > > use static inline stub to avoid #ifdef according to Rob's suggestion > > > > drivers/firmware/efi/efi-init.c | 5 +++++ > > drivers/of/fdt.c | 2 +- > > include/linux/of_fdt.h | 2 ++ > > 3 files changed, 8 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/firmware/efi/efi-init.c b/drivers/firmware/efi/efi-init.c > > index b19ce1a83f91..b2c829e95bd1 100644 > > --- a/drivers/firmware/efi/efi-init.c > > +++ b/drivers/firmware/efi/efi-init.c > > @@ -235,6 +235,11 @@ void __init efi_init(void) > > } > > > > reserve_regions(); > > + /* > > + * For memblock manipulation, the cap should come after the memblock_add(). > > + * And now, memblock is fully populated, it is time to do capping. > > + */ > > + early_init_dt_check_for_usable_mem_range(); > > efi_esrt_init(); > > efi_mokvar_table_init(); > > > > diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c > > index 18a2df431bfd..aa07ef5cab5f 100644 > > --- a/drivers/of/fdt.c > > +++ b/drivers/of/fdt.c > > @@ -972,7 +972,7 @@ static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND; > > * location from flat tree > > * @node: reference to node containing usable memory range location ('chosen') > > */ > > -static void __init early_init_dt_check_for_usable_mem_range(void) > > +void __init early_init_dt_check_for_usable_mem_range(void) > > { > > const __be32 *prop; > > int len; > > diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h > > index cf48983d3c86..ad09beb6d13c 100644 > > --- a/include/linux/of_fdt.h > > +++ b/include/linux/of_fdt.h > > @@ -62,6 +62,7 @@ extern int early_init_dt_scan_chosen(unsigned long node, const char *uname, > > int depth, void *data); > > extern int early_init_dt_scan_memory(unsigned long node, const char *uname, > > int depth, void *data); > > +extern void early_init_dt_check_for_usable_mem_range(void); > > extern int early_init_dt_scan_chosen_stdout(void); > > extern void early_init_fdt_scan_reserved_mem(void); > > extern void early_init_fdt_reserve_self(void); > > @@ -86,6 +87,7 @@ extern void unflatten_and_copy_device_tree(void); > > extern void early_init_devtree(void *); > > extern void early_get_first_memblock_info(void *, phys_addr_t *); > > #else /* CONFIG_OF_EARLY_FLATTREE */ > > +static inline void early_init_dt_check_for_usable_mem_range(void) {} > > static inline int early_init_dt_scan_chosen_stdout(void) { return -ENODEV; } > > static inline void early_init_fdt_scan_reserved_mem(void) {} > > static inline void early_init_fdt_reserve_self(void) {} > > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On 2021/12/15 13:29, Pingfan Liu wrote: > On Wed, Dec 15, 2021 at 11:58:03AM +0800, Leizhen (ThunderTown) wrote: >> >> >> On 2021/12/15 10:13, Pingfan Liu wrote: >>> On arm64, during kdump kernel saves vmcore, it runs into the following bug: >>> ... >>> [ 15.148919] usercopy: Kernel memory exposure attempt detected from SLUB object 'kmem_cache_node' (offset 0, size 4096)! >>> [ 15.159707] ------------[ cut here ]------------ >>> [ 15.164311] kernel BUG at mm/usercopy.c:99! >>> [ 15.168482] Internal error: Oops - BUG: 0 [#1] SMP >>> [ 15.173261] Modules linked in: xfs libcrc32c crct10dif_ce ghash_ce sha2_ce sha256_arm64 sha1_ce sbsa_gwdt ast i2c_algo_bit drm_vram_helper drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops cec drm_ttm_helper ttm drm nvme nvme_core xgene_hwmon i2c_designware_platform i2c_designware_core dm_mirror dm_region_hash dm_log dm_mod overlay squashfs zstd_decompress loop >>> [ 15.206186] CPU: 0 PID: 542 Comm: cp Not tainted 5.16.0-rc4 #1 >>> [ 15.212006] Hardware name: GIGABYTE R272-P30-JG/MP32-AR0-JG, BIOS F12 (SCP: 1.5.20210426) 05/13/2021 >>> [ 15.221125] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) >>> [ 15.228073] pc : usercopy_abort+0x9c/0xa0 >>> [ 15.232074] lr : usercopy_abort+0x9c/0xa0 >>> [ 15.236070] sp : ffff8000121abba0 >>> [ 15.239371] x29: ffff8000121abbb0 x28: 0000000000003000 x27: 0000000000000000 >>> [ 15.246494] x26: 0000000080000400 x25: 0000ffff885c7000 x24: 0000000000000000 >>> [ 15.253617] x23: 000007ff80400000 x22: ffff07ff80401000 x21: 0000000000000001 >>> [ 15.260739] x20: 0000000000001000 x19: ffff07ff80400000 x18: ffffffffffffffff >>> [ 15.267861] x17: 656a626f2042554c x16: 53206d6f72662064 x15: 6574636574656420 >>> [ 15.274983] x14: 74706d6574746120 x13: 2129363930342065 x12: 7a6973202c302074 >>> [ 15.282105] x11: ffffc8b041d1b148 x10: 00000000ffff8000 x9 : ffffc8b04012812c >>> [ 15.289228] x8 : 00000000ffff7fff x7 : ffffc8b041d1b148 x6 : 0000000000000000 >>> [ 15.296349] x5 : 0000000000000000 x4 : 0000000000007fff x3 : 0000000000000000 >>> [ 15.303471] x2 : 0000000000000000 x1 : ffff07ff8c064800 x0 : 000000000000006b >>> [ 15.310593] Call trace: >>> [ 15.313027] usercopy_abort+0x9c/0xa0 >>> [ 15.316677] __check_heap_object+0xd4/0xf0 >>> [ 15.320762] __check_object_size.part.0+0x160/0x1e0 >>> [ 15.325628] __check_object_size+0x2c/0x40 >>> [ 15.329711] copy_oldmem_page+0x7c/0x140 >>> [ 15.333623] read_from_oldmem.part.0+0xfc/0x1c0 >>> [ 15.338142] __read_vmcore.constprop.0+0x23c/0x350 >>> [ 15.342920] read_vmcore+0x28/0x34 >>> [ 15.346309] proc_reg_read+0xb4/0xf0 >>> [ 15.349871] vfs_read+0xb8/0x1f0 >>> [ 15.353088] ksys_read+0x74/0x100 >>> [ 15.356390] __arm64_sys_read+0x28/0x34 >>> ... >>> >>> This bug introduced by commit b261dba2fdb2 ("arm64: kdump: Remove custom >>> linux,usable-memory-range handling"), which moves >>> memblock_cap_memory_range() to fdt, but it breaches the rules that >>> memblock_cap_memory_range() should come after memblock_add() etc as said >>> in commit e888fa7bb882 ("memblock: Check memory add/cap ordering"). >> >> void __init early_init_dt_scan_nodes(void) >> { >> //(1) -->early_init_dt_check_for_usable_mem_range, fill cap_mem_addr >> rc = of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line); >> >> //(2) --> early_init_dt_add_memory_arch --> memblock_add() >> of_scan_flat_dt(early_init_dt_scan_memory, NULL); >> >> //(3) >> memblock_cap_memory_range(cap_mem_addr, cap_mem_size); >> } >> >> I didn't get it. The above step (1),(2),(3) comply with >> commit e888fa7bb882 ("memblock: Check memory add/cap ordering") >> > Well, at this scope, it does. But from a larger scope, let's say on > arm64, > setup_arch > ... > setup_machine_fdt(); //which holds your case > ... > efi_init(); //which call memblock_add, and breach the ordering. > >> Did you see the warning? >> pr_warn("%s: No memory registered yet\n", __func__); >> > Yes, I did see this message, which brings me to commit e888fa7bb882 > ("memblock: Check memory add/cap ordering") > > I am also curious why this bug does not be discovered. Is CONFIG_EFI > on at your case? Yes, Both X86 and ARM64, CONFIG_EFI=y. I used the defconfig. > > Thanks, > > Pingfan >>> >>> As a consequence, the virtual address set up by copy_oldmem_page() does >>> not bail out from the test of virt_addr_valid() in check_heap_object(), >>> and finally hits the BUG_ON(). >>> >>> Since memblock allocator has no idea about when the memblock is fully >>> populated, while efi_init() is aware, so tackling this issue by calling the >>> interface early_init_dt_check_for_usable_mem_range() exposed by of/fdt. >>> >>> Fixes: b261dba2fdb2 ("arm64: kdump: Remove custom linux,usable-memory-range handling") >>> Signed-off-by: Pingfan Liu <kernelfans@gmail.com> >>> Cc: Rob Herring <robh+dt@kernel.org> >>> Cc: Zhen Lei <thunder.leizhen@huawei.com> >>> Cc: Catalin Marinas <catalin.marinas@arm.com> >>> Cc: Will Deacon <will@kernel.org> >>> Cc: Andrew Morton <akpm@linux-foundation.org> >>> Cc: Mike Rapoport <rppt@kernel.org> >>> Cc: Geert Uytterhoeven <geert+renesas@glider.be> >>> Cc: Frank Rowand <frowand.list@gmail.com> >>> Cc: Ard Biesheuvel <ardb@kernel.org> >>> Cc: Nick Terrell <terrelln@fb.com> >>> Cc: linux-arm-kernel@lists.infradead.org >>> To: devicetree@vger.kernel.org >>> To: linux-efi@vger.kernel.org >>> --- >>> v2 -> v3: >>> use static inline stub to avoid #ifdef according to Rob's suggestion >>> >>> drivers/firmware/efi/efi-init.c | 5 +++++ >>> drivers/of/fdt.c | 2 +- >>> include/linux/of_fdt.h | 2 ++ >>> 3 files changed, 8 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/firmware/efi/efi-init.c b/drivers/firmware/efi/efi-init.c >>> index b19ce1a83f91..b2c829e95bd1 100644 >>> --- a/drivers/firmware/efi/efi-init.c >>> +++ b/drivers/firmware/efi/efi-init.c >>> @@ -235,6 +235,11 @@ void __init efi_init(void) >>> } >>> >>> reserve_regions(); >>> + /* >>> + * For memblock manipulation, the cap should come after the memblock_add(). >>> + * And now, memblock is fully populated, it is time to do capping. >>> + */ >>> + early_init_dt_check_for_usable_mem_range(); >>> efi_esrt_init(); >>> efi_mokvar_table_init(); >>> >>> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c >>> index 18a2df431bfd..aa07ef5cab5f 100644 >>> --- a/drivers/of/fdt.c >>> +++ b/drivers/of/fdt.c >>> @@ -972,7 +972,7 @@ static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND; >>> * location from flat tree >>> * @node: reference to node containing usable memory range location ('chosen') >>> */ >>> -static void __init early_init_dt_check_for_usable_mem_range(void) >>> +void __init early_init_dt_check_for_usable_mem_range(void) >>> { >>> const __be32 *prop; >>> int len; >>> diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h >>> index cf48983d3c86..ad09beb6d13c 100644 >>> --- a/include/linux/of_fdt.h >>> +++ b/include/linux/of_fdt.h >>> @@ -62,6 +62,7 @@ extern int early_init_dt_scan_chosen(unsigned long node, const char *uname, >>> int depth, void *data); >>> extern int early_init_dt_scan_memory(unsigned long node, const char *uname, >>> int depth, void *data); >>> +extern void early_init_dt_check_for_usable_mem_range(void); >>> extern int early_init_dt_scan_chosen_stdout(void); >>> extern void early_init_fdt_scan_reserved_mem(void); >>> extern void early_init_fdt_reserve_self(void); >>> @@ -86,6 +87,7 @@ extern void unflatten_and_copy_device_tree(void); >>> extern void early_init_devtree(void *); >>> extern void early_get_first_memblock_info(void *, phys_addr_t *); >>> #else /* CONFIG_OF_EARLY_FLATTREE */ >>> +static inline void early_init_dt_check_for_usable_mem_range(void) {} >>> static inline int early_init_dt_scan_chosen_stdout(void) { return -ENODEV; } >>> static inline void early_init_fdt_scan_reserved_mem(void) {} >>> static inline void early_init_fdt_reserve_self(void) {} >>> >> >> _______________________________________________ >> linux-arm-kernel mailing list >> linux-arm-kernel@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > . >
On Wed, Dec 15, 2021 at 02:53:38PM +0800, Leizhen (ThunderTown) wrote: > > > On 2021/12/15 13:29, Pingfan Liu wrote: > > On Wed, Dec 15, 2021 at 11:58:03AM +0800, Leizhen (ThunderTown) wrote: > >> > >> > >> On 2021/12/15 10:13, Pingfan Liu wrote: > >>> On arm64, during kdump kernel saves vmcore, it runs into the following bug: > >>> ... > >>> [ 15.148919] usercopy: Kernel memory exposure attempt detected from SLUB object 'kmem_cache_node' (offset 0, size 4096)! > >>> [ 15.159707] ------------[ cut here ]------------ > >>> [ 15.164311] kernel BUG at mm/usercopy.c:99! > >>> [ 15.168482] Internal error: Oops - BUG: 0 [#1] SMP > >>> [ 15.173261] Modules linked in: xfs libcrc32c crct10dif_ce ghash_ce sha2_ce sha256_arm64 sha1_ce sbsa_gwdt ast i2c_algo_bit drm_vram_helper drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops cec drm_ttm_helper ttm drm nvme nvme_core xgene_hwmon i2c_designware_platform i2c_designware_core dm_mirror dm_region_hash dm_log dm_mod overlay squashfs zstd_decompress loop > >>> [ 15.206186] CPU: 0 PID: 542 Comm: cp Not tainted 5.16.0-rc4 #1 > >>> [ 15.212006] Hardware name: GIGABYTE R272-P30-JG/MP32-AR0-JG, BIOS F12 (SCP: 1.5.20210426) 05/13/2021 > >>> [ 15.221125] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) > >>> [ 15.228073] pc : usercopy_abort+0x9c/0xa0 > >>> [ 15.232074] lr : usercopy_abort+0x9c/0xa0 > >>> [ 15.236070] sp : ffff8000121abba0 > >>> [ 15.239371] x29: ffff8000121abbb0 x28: 0000000000003000 x27: 0000000000000000 > >>> [ 15.246494] x26: 0000000080000400 x25: 0000ffff885c7000 x24: 0000000000000000 > >>> [ 15.253617] x23: 000007ff80400000 x22: ffff07ff80401000 x21: 0000000000000001 > >>> [ 15.260739] x20: 0000000000001000 x19: ffff07ff80400000 x18: ffffffffffffffff > >>> [ 15.267861] x17: 656a626f2042554c x16: 53206d6f72662064 x15: 6574636574656420 > >>> [ 15.274983] x14: 74706d6574746120 x13: 2129363930342065 x12: 7a6973202c302074 > >>> [ 15.282105] x11: ffffc8b041d1b148 x10: 00000000ffff8000 x9 : ffffc8b04012812c > >>> [ 15.289228] x8 : 00000000ffff7fff x7 : ffffc8b041d1b148 x6 : 0000000000000000 > >>> [ 15.296349] x5 : 0000000000000000 x4 : 0000000000007fff x3 : 0000000000000000 > >>> [ 15.303471] x2 : 0000000000000000 x1 : ffff07ff8c064800 x0 : 000000000000006b > >>> [ 15.310593] Call trace: > >>> [ 15.313027] usercopy_abort+0x9c/0xa0 > >>> [ 15.316677] __check_heap_object+0xd4/0xf0 > >>> [ 15.320762] __check_object_size.part.0+0x160/0x1e0 > >>> [ 15.325628] __check_object_size+0x2c/0x40 > >>> [ 15.329711] copy_oldmem_page+0x7c/0x140 > >>> [ 15.333623] read_from_oldmem.part.0+0xfc/0x1c0 > >>> [ 15.338142] __read_vmcore.constprop.0+0x23c/0x350 > >>> [ 15.342920] read_vmcore+0x28/0x34 > >>> [ 15.346309] proc_reg_read+0xb4/0xf0 > >>> [ 15.349871] vfs_read+0xb8/0x1f0 > >>> [ 15.353088] ksys_read+0x74/0x100 > >>> [ 15.356390] __arm64_sys_read+0x28/0x34 > >>> ... > >>> > >>> This bug introduced by commit b261dba2fdb2 ("arm64: kdump: Remove custom > >>> linux,usable-memory-range handling"), which moves > >>> memblock_cap_memory_range() to fdt, but it breaches the rules that > >>> memblock_cap_memory_range() should come after memblock_add() etc as said > >>> in commit e888fa7bb882 ("memblock: Check memory add/cap ordering"). > >> > >> void __init early_init_dt_scan_nodes(void) > >> { > >> //(1) -->early_init_dt_check_for_usable_mem_range, fill cap_mem_addr > >> rc = of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line); > >> > >> //(2) --> early_init_dt_add_memory_arch --> memblock_add() > >> of_scan_flat_dt(early_init_dt_scan_memory, NULL); > >> > >> //(3) > >> memblock_cap_memory_range(cap_mem_addr, cap_mem_size); > >> } > >> > >> I didn't get it. The above step (1),(2),(3) comply with > >> commit e888fa7bb882 ("memblock: Check memory add/cap ordering") > >> > > Well, at this scope, it does. But from a larger scope, let's say on > > arm64, > > setup_arch > > ... > > setup_machine_fdt(); //which holds your case > > ... > > efi_init(); //which call memblock_add, and breach the ordering. > > > >> Did you see the warning? > >> pr_warn("%s: No memory registered yet\n", __func__); > >> > > Yes, I did see this message, which brings me to commit e888fa7bb882 > > ("memblock: Check memory add/cap ordering") > > > > I am also curious why this bug does not be discovered. Is CONFIG_EFI > > on at your case? > > Yes, Both X86 and ARM64, CONFIG_EFI=y. I used the defconfig. > Maybe due to different md? Because efi_init()->reserve_regions()->early_init_dt_add_memory_arch()->memblock_add() on arm64, if is_memory(md). This is the path breaching the rule during my test. Thanks Pingfan > > > > Thanks, > > > > Pingfan > >>> > >>> As a consequence, the virtual address set up by copy_oldmem_page() does > >>> not bail out from the test of virt_addr_valid() in check_heap_object(), > >>> and finally hits the BUG_ON(). > >>> > >>> Since memblock allocator has no idea about when the memblock is fully > >>> populated, while efi_init() is aware, so tackling this issue by calling the > >>> interface early_init_dt_check_for_usable_mem_range() exposed by of/fdt. > >>> > >>> Fixes: b261dba2fdb2 ("arm64: kdump: Remove custom linux,usable-memory-range handling") > >>> Signed-off-by: Pingfan Liu <kernelfans@gmail.com> > >>> Cc: Rob Herring <robh+dt@kernel.org> > >>> Cc: Zhen Lei <thunder.leizhen@huawei.com> > >>> Cc: Catalin Marinas <catalin.marinas@arm.com> > >>> Cc: Will Deacon <will@kernel.org> > >>> Cc: Andrew Morton <akpm@linux-foundation.org> > >>> Cc: Mike Rapoport <rppt@kernel.org> > >>> Cc: Geert Uytterhoeven <geert+renesas@glider.be> > >>> Cc: Frank Rowand <frowand.list@gmail.com> > >>> Cc: Ard Biesheuvel <ardb@kernel.org> > >>> Cc: Nick Terrell <terrelln@fb.com> > >>> Cc: linux-arm-kernel@lists.infradead.org > >>> To: devicetree@vger.kernel.org > >>> To: linux-efi@vger.kernel.org > >>> --- > >>> v2 -> v3: > >>> use static inline stub to avoid #ifdef according to Rob's suggestion > >>> > >>> drivers/firmware/efi/efi-init.c | 5 +++++ > >>> drivers/of/fdt.c | 2 +- > >>> include/linux/of_fdt.h | 2 ++ > >>> 3 files changed, 8 insertions(+), 1 deletion(-) > >>> > >>> diff --git a/drivers/firmware/efi/efi-init.c b/drivers/firmware/efi/efi-init.c > >>> index b19ce1a83f91..b2c829e95bd1 100644 > >>> --- a/drivers/firmware/efi/efi-init.c > >>> +++ b/drivers/firmware/efi/efi-init.c > >>> @@ -235,6 +235,11 @@ void __init efi_init(void) > >>> } > >>> > >>> reserve_regions(); > >>> + /* > >>> + * For memblock manipulation, the cap should come after the memblock_add(). > >>> + * And now, memblock is fully populated, it is time to do capping. > >>> + */ > >>> + early_init_dt_check_for_usable_mem_range(); > >>> efi_esrt_init(); > >>> efi_mokvar_table_init(); > >>> > >>> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c > >>> index 18a2df431bfd..aa07ef5cab5f 100644 > >>> --- a/drivers/of/fdt.c > >>> +++ b/drivers/of/fdt.c > >>> @@ -972,7 +972,7 @@ static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND; > >>> * location from flat tree > >>> * @node: reference to node containing usable memory range location ('chosen') > >>> */ > >>> -static void __init early_init_dt_check_for_usable_mem_range(void) > >>> +void __init early_init_dt_check_for_usable_mem_range(void) > >>> { > >>> const __be32 *prop; > >>> int len; > >>> diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h > >>> index cf48983d3c86..ad09beb6d13c 100644 > >>> --- a/include/linux/of_fdt.h > >>> +++ b/include/linux/of_fdt.h > >>> @@ -62,6 +62,7 @@ extern int early_init_dt_scan_chosen(unsigned long node, const char *uname, > >>> int depth, void *data); > >>> extern int early_init_dt_scan_memory(unsigned long node, const char *uname, > >>> int depth, void *data); > >>> +extern void early_init_dt_check_for_usable_mem_range(void); > >>> extern int early_init_dt_scan_chosen_stdout(void); > >>> extern void early_init_fdt_scan_reserved_mem(void); > >>> extern void early_init_fdt_reserve_self(void); > >>> @@ -86,6 +87,7 @@ extern void unflatten_and_copy_device_tree(void); > >>> extern void early_init_devtree(void *); > >>> extern void early_get_first_memblock_info(void *, phys_addr_t *); > >>> #else /* CONFIG_OF_EARLY_FLATTREE */ > >>> +static inline void early_init_dt_check_for_usable_mem_range(void) {} > >>> static inline int early_init_dt_scan_chosen_stdout(void) { return -ENODEV; } > >>> static inline void early_init_fdt_scan_reserved_mem(void) {} > >>> static inline void early_init_fdt_reserve_self(void) {} > >>> > >> > >> _______________________________________________ > >> linux-arm-kernel mailing list > >> linux-arm-kernel@lists.infradead.org > >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > > . > > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On Wed, Dec 15, 2021 at 12:53 AM Leizhen (ThunderTown) <thunder.leizhen@huawei.com> wrote: > > > > On 2021/12/15 13:29, Pingfan Liu wrote: > > On Wed, Dec 15, 2021 at 11:58:03AM +0800, Leizhen (ThunderTown) wrote: > >> > >> > >> On 2021/12/15 10:13, Pingfan Liu wrote: > >>> On arm64, during kdump kernel saves vmcore, it runs into the following bug: > >>> ... > >>> [ 15.148919] usercopy: Kernel memory exposure attempt detected from SLUB object 'kmem_cache_node' (offset 0, size 4096)! > >>> [ 15.159707] ------------[ cut here ]------------ > >>> [ 15.164311] kernel BUG at mm/usercopy.c:99! > >>> [ 15.168482] Internal error: Oops - BUG: 0 [#1] SMP > >>> [ 15.173261] Modules linked in: xfs libcrc32c crct10dif_ce ghash_ce sha2_ce sha256_arm64 sha1_ce sbsa_gwdt ast i2c_algo_bit drm_vram_helper drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops cec drm_ttm_helper ttm drm nvme nvme_core xgene_hwmon i2c_designware_platform i2c_designware_core dm_mirror dm_region_hash dm_log dm_mod overlay squashfs zstd_decompress loop > >>> [ 15.206186] CPU: 0 PID: 542 Comm: cp Not tainted 5.16.0-rc4 #1 > >>> [ 15.212006] Hardware name: GIGABYTE R272-P30-JG/MP32-AR0-JG, BIOS F12 (SCP: 1.5.20210426) 05/13/2021 > >>> [ 15.221125] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) > >>> [ 15.228073] pc : usercopy_abort+0x9c/0xa0 > >>> [ 15.232074] lr : usercopy_abort+0x9c/0xa0 > >>> [ 15.236070] sp : ffff8000121abba0 > >>> [ 15.239371] x29: ffff8000121abbb0 x28: 0000000000003000 x27: 0000000000000000 > >>> [ 15.246494] x26: 0000000080000400 x25: 0000ffff885c7000 x24: 0000000000000000 > >>> [ 15.253617] x23: 000007ff80400000 x22: ffff07ff80401000 x21: 0000000000000001 > >>> [ 15.260739] x20: 0000000000001000 x19: ffff07ff80400000 x18: ffffffffffffffff > >>> [ 15.267861] x17: 656a626f2042554c x16: 53206d6f72662064 x15: 6574636574656420 > >>> [ 15.274983] x14: 74706d6574746120 x13: 2129363930342065 x12: 7a6973202c302074 > >>> [ 15.282105] x11: ffffc8b041d1b148 x10: 00000000ffff8000 x9 : ffffc8b04012812c > >>> [ 15.289228] x8 : 00000000ffff7fff x7 : ffffc8b041d1b148 x6 : 0000000000000000 > >>> [ 15.296349] x5 : 0000000000000000 x4 : 0000000000007fff x3 : 0000000000000000 > >>> [ 15.303471] x2 : 0000000000000000 x1 : ffff07ff8c064800 x0 : 000000000000006b > >>> [ 15.310593] Call trace: > >>> [ 15.313027] usercopy_abort+0x9c/0xa0 > >>> [ 15.316677] __check_heap_object+0xd4/0xf0 > >>> [ 15.320762] __check_object_size.part.0+0x160/0x1e0 > >>> [ 15.325628] __check_object_size+0x2c/0x40 > >>> [ 15.329711] copy_oldmem_page+0x7c/0x140 > >>> [ 15.333623] read_from_oldmem.part.0+0xfc/0x1c0 > >>> [ 15.338142] __read_vmcore.constprop.0+0x23c/0x350 > >>> [ 15.342920] read_vmcore+0x28/0x34 > >>> [ 15.346309] proc_reg_read+0xb4/0xf0 > >>> [ 15.349871] vfs_read+0xb8/0x1f0 > >>> [ 15.353088] ksys_read+0x74/0x100 > >>> [ 15.356390] __arm64_sys_read+0x28/0x34 > >>> ... > >>> > >>> This bug introduced by commit b261dba2fdb2 ("arm64: kdump: Remove custom > >>> linux,usable-memory-range handling"), which moves > >>> memblock_cap_memory_range() to fdt, but it breaches the rules that > >>> memblock_cap_memory_range() should come after memblock_add() etc as said > >>> in commit e888fa7bb882 ("memblock: Check memory add/cap ordering"). > >> > >> void __init early_init_dt_scan_nodes(void) > >> { > >> //(1) -->early_init_dt_check_for_usable_mem_range, fill cap_mem_addr > >> rc = of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line); > >> > >> //(2) --> early_init_dt_add_memory_arch --> memblock_add() > >> of_scan_flat_dt(early_init_dt_scan_memory, NULL); > >> > >> //(3) > >> memblock_cap_memory_range(cap_mem_addr, cap_mem_size); > >> } > >> > >> I didn't get it. The above step (1),(2),(3) comply with > >> commit e888fa7bb882 ("memblock: Check memory add/cap ordering") > >> > > Well, at this scope, it does. But from a larger scope, let's say on > > arm64, > > setup_arch > > ... > > setup_machine_fdt(); //which holds your case > > ... > > efi_init(); //which call memblock_add, and breach the ordering. > > > >> Did you see the warning? > >> pr_warn("%s: No memory registered yet\n", __func__); > >> > > Yes, I did see this message, which brings me to commit e888fa7bb882 > > ("memblock: Check memory add/cap ordering") > > > > I am also curious why this bug does not be discovered. Is CONFIG_EFI > > on at your case? > > Yes, Both X86 and ARM64, CONFIG_EFI=y. I used the defconfig. Are you booting using EFI though? efi_init() removes all memblocks that may have been setup from the DT and adds memblocks using the EFI memory map information. Rob
On 2021/12/15 23:05, Rob Herring wrote: > On Wed, Dec 15, 2021 at 12:53 AM Leizhen (ThunderTown) > <thunder.leizhen@huawei.com> wrote: >> >> >> >> On 2021/12/15 13:29, Pingfan Liu wrote: >>> On Wed, Dec 15, 2021 at 11:58:03AM +0800, Leizhen (ThunderTown) wrote: >>>> >>>> >>>> On 2021/12/15 10:13, Pingfan Liu wrote: >>>>> On arm64, during kdump kernel saves vmcore, it runs into the following bug: >>>>> ... >>>>> [ 15.148919] usercopy: Kernel memory exposure attempt detected from SLUB object 'kmem_cache_node' (offset 0, size 4096)! >>>>> [ 15.159707] ------------[ cut here ]------------ >>>>> [ 15.164311] kernel BUG at mm/usercopy.c:99! >>>>> [ 15.168482] Internal error: Oops - BUG: 0 [#1] SMP >>>>> [ 15.173261] Modules linked in: xfs libcrc32c crct10dif_ce ghash_ce sha2_ce sha256_arm64 sha1_ce sbsa_gwdt ast i2c_algo_bit drm_vram_helper drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops cec drm_ttm_helper ttm drm nvme nvme_core xgene_hwmon i2c_designware_platform i2c_designware_core dm_mirror dm_region_hash dm_log dm_mod overlay squashfs zstd_decompress loop >>>>> [ 15.206186] CPU: 0 PID: 542 Comm: cp Not tainted 5.16.0-rc4 #1 >>>>> [ 15.212006] Hardware name: GIGABYTE R272-P30-JG/MP32-AR0-JG, BIOS F12 (SCP: 1.5.20210426) 05/13/2021 >>>>> [ 15.221125] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) >>>>> [ 15.228073] pc : usercopy_abort+0x9c/0xa0 >>>>> [ 15.232074] lr : usercopy_abort+0x9c/0xa0 >>>>> [ 15.236070] sp : ffff8000121abba0 >>>>> [ 15.239371] x29: ffff8000121abbb0 x28: 0000000000003000 x27: 0000000000000000 >>>>> [ 15.246494] x26: 0000000080000400 x25: 0000ffff885c7000 x24: 0000000000000000 >>>>> [ 15.253617] x23: 000007ff80400000 x22: ffff07ff80401000 x21: 0000000000000001 >>>>> [ 15.260739] x20: 0000000000001000 x19: ffff07ff80400000 x18: ffffffffffffffff >>>>> [ 15.267861] x17: 656a626f2042554c x16: 53206d6f72662064 x15: 6574636574656420 >>>>> [ 15.274983] x14: 74706d6574746120 x13: 2129363930342065 x12: 7a6973202c302074 >>>>> [ 15.282105] x11: ffffc8b041d1b148 x10: 00000000ffff8000 x9 : ffffc8b04012812c >>>>> [ 15.289228] x8 : 00000000ffff7fff x7 : ffffc8b041d1b148 x6 : 0000000000000000 >>>>> [ 15.296349] x5 : 0000000000000000 x4 : 0000000000007fff x3 : 0000000000000000 >>>>> [ 15.303471] x2 : 0000000000000000 x1 : ffff07ff8c064800 x0 : 000000000000006b >>>>> [ 15.310593] Call trace: >>>>> [ 15.313027] usercopy_abort+0x9c/0xa0 >>>>> [ 15.316677] __check_heap_object+0xd4/0xf0 >>>>> [ 15.320762] __check_object_size.part.0+0x160/0x1e0 >>>>> [ 15.325628] __check_object_size+0x2c/0x40 >>>>> [ 15.329711] copy_oldmem_page+0x7c/0x140 >>>>> [ 15.333623] read_from_oldmem.part.0+0xfc/0x1c0 >>>>> [ 15.338142] __read_vmcore.constprop.0+0x23c/0x350 >>>>> [ 15.342920] read_vmcore+0x28/0x34 >>>>> [ 15.346309] proc_reg_read+0xb4/0xf0 >>>>> [ 15.349871] vfs_read+0xb8/0x1f0 >>>>> [ 15.353088] ksys_read+0x74/0x100 >>>>> [ 15.356390] __arm64_sys_read+0x28/0x34 >>>>> ... >>>>> >>>>> This bug introduced by commit b261dba2fdb2 ("arm64: kdump: Remove custom >>>>> linux,usable-memory-range handling"), which moves >>>>> memblock_cap_memory_range() to fdt, but it breaches the rules that >>>>> memblock_cap_memory_range() should come after memblock_add() etc as said >>>>> in commit e888fa7bb882 ("memblock: Check memory add/cap ordering"). >>>> >>>> void __init early_init_dt_scan_nodes(void) >>>> { >>>> //(1) -->early_init_dt_check_for_usable_mem_range, fill cap_mem_addr >>>> rc = of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line); >>>> >>>> //(2) --> early_init_dt_add_memory_arch --> memblock_add() >>>> of_scan_flat_dt(early_init_dt_scan_memory, NULL); >>>> >>>> //(3) >>>> memblock_cap_memory_range(cap_mem_addr, cap_mem_size); >>>> } >>>> >>>> I didn't get it. The above step (1),(2),(3) comply with >>>> commit e888fa7bb882 ("memblock: Check memory add/cap ordering") >>>> >>> Well, at this scope, it does. But from a larger scope, let's say on >>> arm64, >>> setup_arch >>> ... >>> setup_machine_fdt(); //which holds your case >>> ... >>> efi_init(); //which call memblock_add, and breach the ordering. >>> >>>> Did you see the warning? >>>> pr_warn("%s: No memory registered yet\n", __func__); >>>> >>> Yes, I did see this message, which brings me to commit e888fa7bb882 >>> ("memblock: Check memory add/cap ordering") >>> >>> I am also curious why this bug does not be discovered. Is CONFIG_EFI >>> on at your case? >> >> Yes, Both X86 and ARM64, CONFIG_EFI=y. I used the defconfig. > > Are you booting using EFI though? efi_init() removes all memblocks > that may have been setup from the DT and adds memblocks using the EFI > memory map information. Sorry, I tested it with QEMU. I checked that efi_system_table is not exist. > > Rob > . >
On Tue, Dec 14, 2021 at 8:14 PM Pingfan Liu <kernelfans@gmail.com> wrote: > > On arm64, during kdump kernel saves vmcore, it runs into the following bug: > ... > [ 15.148919] usercopy: Kernel memory exposure attempt detected from SLUB object 'kmem_cache_node' (offset 0, size 4096)! > [ 15.159707] ------------[ cut here ]------------ > [ 15.164311] kernel BUG at mm/usercopy.c:99! > [ 15.168482] Internal error: Oops - BUG: 0 [#1] SMP > [ 15.173261] Modules linked in: xfs libcrc32c crct10dif_ce ghash_ce sha2_ce sha256_arm64 sha1_ce sbsa_gwdt ast i2c_algo_bit drm_vram_helper drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops cec drm_ttm_helper ttm drm nvme nvme_core xgene_hwmon i2c_designware_platform i2c_designware_core dm_mirror dm_region_hash dm_log dm_mod overlay squashfs zstd_decompress loop > [ 15.206186] CPU: 0 PID: 542 Comm: cp Not tainted 5.16.0-rc4 #1 > [ 15.212006] Hardware name: GIGABYTE R272-P30-JG/MP32-AR0-JG, BIOS F12 (SCP: 1.5.20210426) 05/13/2021 > [ 15.221125] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) > [ 15.228073] pc : usercopy_abort+0x9c/0xa0 > [ 15.232074] lr : usercopy_abort+0x9c/0xa0 > [ 15.236070] sp : ffff8000121abba0 > [ 15.239371] x29: ffff8000121abbb0 x28: 0000000000003000 x27: 0000000000000000 > [ 15.246494] x26: 0000000080000400 x25: 0000ffff885c7000 x24: 0000000000000000 > [ 15.253617] x23: 000007ff80400000 x22: ffff07ff80401000 x21: 0000000000000001 > [ 15.260739] x20: 0000000000001000 x19: ffff07ff80400000 x18: ffffffffffffffff > [ 15.267861] x17: 656a626f2042554c x16: 53206d6f72662064 x15: 6574636574656420 > [ 15.274983] x14: 74706d6574746120 x13: 2129363930342065 x12: 7a6973202c302074 > [ 15.282105] x11: ffffc8b041d1b148 x10: 00000000ffff8000 x9 : ffffc8b04012812c > [ 15.289228] x8 : 00000000ffff7fff x7 : ffffc8b041d1b148 x6 : 0000000000000000 > [ 15.296349] x5 : 0000000000000000 x4 : 0000000000007fff x3 : 0000000000000000 > [ 15.303471] x2 : 0000000000000000 x1 : ffff07ff8c064800 x0 : 000000000000006b > [ 15.310593] Call trace: > [ 15.313027] usercopy_abort+0x9c/0xa0 > [ 15.316677] __check_heap_object+0xd4/0xf0 > [ 15.320762] __check_object_size.part.0+0x160/0x1e0 > [ 15.325628] __check_object_size+0x2c/0x40 > [ 15.329711] copy_oldmem_page+0x7c/0x140 > [ 15.333623] read_from_oldmem.part.0+0xfc/0x1c0 > [ 15.338142] __read_vmcore.constprop.0+0x23c/0x350 > [ 15.342920] read_vmcore+0x28/0x34 > [ 15.346309] proc_reg_read+0xb4/0xf0 > [ 15.349871] vfs_read+0xb8/0x1f0 > [ 15.353088] ksys_read+0x74/0x100 > [ 15.356390] __arm64_sys_read+0x28/0x34 > ... > > This bug introduced by commit b261dba2fdb2 ("arm64: kdump: Remove custom > linux,usable-memory-range handling"), which moves > memblock_cap_memory_range() to fdt, but it breaches the rules that > memblock_cap_memory_range() should come after memblock_add() etc as said > in commit e888fa7bb882 ("memblock: Check memory add/cap ordering"). > > As a consequence, the virtual address set up by copy_oldmem_page() does > not bail out from the test of virt_addr_valid() in check_heap_object(), > and finally hits the BUG_ON(). > > Since memblock allocator has no idea about when the memblock is fully > populated, while efi_init() is aware, so tackling this issue by calling the > interface early_init_dt_check_for_usable_mem_range() exposed by of/fdt. > > Fixes: b261dba2fdb2 ("arm64: kdump: Remove custom linux,usable-memory-range handling") > Signed-off-by: Pingfan Liu <kernelfans@gmail.com> > Cc: Rob Herring <robh+dt@kernel.org> > Cc: Zhen Lei <thunder.leizhen@huawei.com> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Will Deacon <will@kernel.org> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Mike Rapoport <rppt@kernel.org> > Cc: Geert Uytterhoeven <geert+renesas@glider.be> > Cc: Frank Rowand <frowand.list@gmail.com> > Cc: Ard Biesheuvel <ardb@kernel.org> > Cc: Nick Terrell <terrelln@fb.com> > Cc: linux-arm-kernel@lists.infradead.org > To: devicetree@vger.kernel.org > To: linux-efi@vger.kernel.org > --- > v2 -> v3: > use static inline stub to avoid #ifdef according to Rob's suggestion > > drivers/firmware/efi/efi-init.c | 5 +++++ > drivers/of/fdt.c | 2 +- > include/linux/of_fdt.h | 2 ++ > 3 files changed, 8 insertions(+), 1 deletion(-) Looks good to me. I'll apply and send to Linus once the EFI folks ack this. Rob
On Fri, 17 Dec 2021 at 16:08, Rob Herring <robh+dt@kernel.org> wrote: > > On Tue, Dec 14, 2021 at 8:14 PM Pingfan Liu <kernelfans@gmail.com> wrote: > > > > On arm64, during kdump kernel saves vmcore, it runs into the following bug: > > ... > > [ 15.148919] usercopy: Kernel memory exposure attempt detected from SLUB object 'kmem_cache_node' (offset 0, size 4096)! > > [ 15.159707] ------------[ cut here ]------------ > > [ 15.164311] kernel BUG at mm/usercopy.c:99! > > [ 15.168482] Internal error: Oops - BUG: 0 [#1] SMP > > [ 15.173261] Modules linked in: xfs libcrc32c crct10dif_ce ghash_ce sha2_ce sha256_arm64 sha1_ce sbsa_gwdt ast i2c_algo_bit drm_vram_helper drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops cec drm_ttm_helper ttm drm nvme nvme_core xgene_hwmon i2c_designware_platform i2c_designware_core dm_mirror dm_region_hash dm_log dm_mod overlay squashfs zstd_decompress loop > > [ 15.206186] CPU: 0 PID: 542 Comm: cp Not tainted 5.16.0-rc4 #1 > > [ 15.212006] Hardware name: GIGABYTE R272-P30-JG/MP32-AR0-JG, BIOS F12 (SCP: 1.5.20210426) 05/13/2021 > > [ 15.221125] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) > > [ 15.228073] pc : usercopy_abort+0x9c/0xa0 > > [ 15.232074] lr : usercopy_abort+0x9c/0xa0 > > [ 15.236070] sp : ffff8000121abba0 > > [ 15.239371] x29: ffff8000121abbb0 x28: 0000000000003000 x27: 0000000000000000 > > [ 15.246494] x26: 0000000080000400 x25: 0000ffff885c7000 x24: 0000000000000000 > > [ 15.253617] x23: 000007ff80400000 x22: ffff07ff80401000 x21: 0000000000000001 > > [ 15.260739] x20: 0000000000001000 x19: ffff07ff80400000 x18: ffffffffffffffff > > [ 15.267861] x17: 656a626f2042554c x16: 53206d6f72662064 x15: 6574636574656420 > > [ 15.274983] x14: 74706d6574746120 x13: 2129363930342065 x12: 7a6973202c302074 > > [ 15.282105] x11: ffffc8b041d1b148 x10: 00000000ffff8000 x9 : ffffc8b04012812c > > [ 15.289228] x8 : 00000000ffff7fff x7 : ffffc8b041d1b148 x6 : 0000000000000000 > > [ 15.296349] x5 : 0000000000000000 x4 : 0000000000007fff x3 : 0000000000000000 > > [ 15.303471] x2 : 0000000000000000 x1 : ffff07ff8c064800 x0 : 000000000000006b > > [ 15.310593] Call trace: > > [ 15.313027] usercopy_abort+0x9c/0xa0 > > [ 15.316677] __check_heap_object+0xd4/0xf0 > > [ 15.320762] __check_object_size.part.0+0x160/0x1e0 > > [ 15.325628] __check_object_size+0x2c/0x40 > > [ 15.329711] copy_oldmem_page+0x7c/0x140 > > [ 15.333623] read_from_oldmem.part.0+0xfc/0x1c0 > > [ 15.338142] __read_vmcore.constprop.0+0x23c/0x350 > > [ 15.342920] read_vmcore+0x28/0x34 > > [ 15.346309] proc_reg_read+0xb4/0xf0 > > [ 15.349871] vfs_read+0xb8/0x1f0 > > [ 15.353088] ksys_read+0x74/0x100 > > [ 15.356390] __arm64_sys_read+0x28/0x34 > > ... > > > > This bug introduced by commit b261dba2fdb2 ("arm64: kdump: Remove custom > > linux,usable-memory-range handling"), which moves > > memblock_cap_memory_range() to fdt, but it breaches the rules that > > memblock_cap_memory_range() should come after memblock_add() etc as said > > in commit e888fa7bb882 ("memblock: Check memory add/cap ordering"). > > > > As a consequence, the virtual address set up by copy_oldmem_page() does > > not bail out from the test of virt_addr_valid() in check_heap_object(), > > and finally hits the BUG_ON(). > > > > Since memblock allocator has no idea about when the memblock is fully > > populated, while efi_init() is aware, so tackling this issue by calling the > > interface early_init_dt_check_for_usable_mem_range() exposed by of/fdt. > > > > Fixes: b261dba2fdb2 ("arm64: kdump: Remove custom linux,usable-memory-range handling") > > Signed-off-by: Pingfan Liu <kernelfans@gmail.com> > > Cc: Rob Herring <robh+dt@kernel.org> > > Cc: Zhen Lei <thunder.leizhen@huawei.com> > > Cc: Catalin Marinas <catalin.marinas@arm.com> > > Cc: Will Deacon <will@kernel.org> > > Cc: Andrew Morton <akpm@linux-foundation.org> > > Cc: Mike Rapoport <rppt@kernel.org> > > Cc: Geert Uytterhoeven <geert+renesas@glider.be> > > Cc: Frank Rowand <frowand.list@gmail.com> > > Cc: Ard Biesheuvel <ardb@kernel.org> > > Cc: Nick Terrell <terrelln@fb.com> > > Cc: linux-arm-kernel@lists.infradead.org > > To: devicetree@vger.kernel.org > > To: linux-efi@vger.kernel.org > > --- > > v2 -> v3: > > use static inline stub to avoid #ifdef according to Rob's suggestion > > > > drivers/firmware/efi/efi-init.c | 5 +++++ > > drivers/of/fdt.c | 2 +- > > include/linux/of_fdt.h | 2 ++ > > 3 files changed, 8 insertions(+), 1 deletion(-) > > Looks good to me. I'll apply and send to Linus once the EFI folks ack this. > Where needed in the series, Acked-by: Ard Biesheuvel <ardb@kernel.org>
On Wed, 15 Dec 2021 10:13:48 +0800, Pingfan Liu wrote: > On arm64, during kdump kernel saves vmcore, it runs into the following bug: > ... > [ 15.148919] usercopy: Kernel memory exposure attempt detected from SLUB object 'kmem_cache_node' (offset 0, size 4096)! > [ 15.159707] ------------[ cut here ]------------ > [ 15.164311] kernel BUG at mm/usercopy.c:99! > [ 15.168482] Internal error: Oops - BUG: 0 [#1] SMP > [ 15.173261] Modules linked in: xfs libcrc32c crct10dif_ce ghash_ce sha2_ce sha256_arm64 sha1_ce sbsa_gwdt ast i2c_algo_bit drm_vram_helper drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops cec drm_ttm_helper ttm drm nvme nvme_core xgene_hwmon i2c_designware_platform i2c_designware_core dm_mirror dm_region_hash dm_log dm_mod overlay squashfs zstd_decompress loop > [ 15.206186] CPU: 0 PID: 542 Comm: cp Not tainted 5.16.0-rc4 #1 > [ 15.212006] Hardware name: GIGABYTE R272-P30-JG/MP32-AR0-JG, BIOS F12 (SCP: 1.5.20210426) 05/13/2021 > [ 15.221125] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) > [ 15.228073] pc : usercopy_abort+0x9c/0xa0 > [ 15.232074] lr : usercopy_abort+0x9c/0xa0 > [ 15.236070] sp : ffff8000121abba0 > [ 15.239371] x29: ffff8000121abbb0 x28: 0000000000003000 x27: 0000000000000000 > [ 15.246494] x26: 0000000080000400 x25: 0000ffff885c7000 x24: 0000000000000000 > [ 15.253617] x23: 000007ff80400000 x22: ffff07ff80401000 x21: 0000000000000001 > [ 15.260739] x20: 0000000000001000 x19: ffff07ff80400000 x18: ffffffffffffffff > [ 15.267861] x17: 656a626f2042554c x16: 53206d6f72662064 x15: 6574636574656420 > [ 15.274983] x14: 74706d6574746120 x13: 2129363930342065 x12: 7a6973202c302074 > [ 15.282105] x11: ffffc8b041d1b148 x10: 00000000ffff8000 x9 : ffffc8b04012812c > [ 15.289228] x8 : 00000000ffff7fff x7 : ffffc8b041d1b148 x6 : 0000000000000000 > [ 15.296349] x5 : 0000000000000000 x4 : 0000000000007fff x3 : 0000000000000000 > [ 15.303471] x2 : 0000000000000000 x1 : ffff07ff8c064800 x0 : 000000000000006b > [ 15.310593] Call trace: > [ 15.313027] usercopy_abort+0x9c/0xa0 > [ 15.316677] __check_heap_object+0xd4/0xf0 > [ 15.320762] __check_object_size.part.0+0x160/0x1e0 > [ 15.325628] __check_object_size+0x2c/0x40 > [ 15.329711] copy_oldmem_page+0x7c/0x140 > [ 15.333623] read_from_oldmem.part.0+0xfc/0x1c0 > [ 15.338142] __read_vmcore.constprop.0+0x23c/0x350 > [ 15.342920] read_vmcore+0x28/0x34 > [ 15.346309] proc_reg_read+0xb4/0xf0 > [ 15.349871] vfs_read+0xb8/0x1f0 > [ 15.353088] ksys_read+0x74/0x100 > [ 15.356390] __arm64_sys_read+0x28/0x34 > ... > > This bug introduced by commit b261dba2fdb2 ("arm64: kdump: Remove custom > linux,usable-memory-range handling"), which moves > memblock_cap_memory_range() to fdt, but it breaches the rules that > memblock_cap_memory_range() should come after memblock_add() etc as said > in commit e888fa7bb882 ("memblock: Check memory add/cap ordering"). > > As a consequence, the virtual address set up by copy_oldmem_page() does > not bail out from the test of virt_addr_valid() in check_heap_object(), > and finally hits the BUG_ON(). > > Since memblock allocator has no idea about when the memblock is fully > populated, while efi_init() is aware, so tackling this issue by calling the > interface early_init_dt_check_for_usable_mem_range() exposed by of/fdt. > > Fixes: b261dba2fdb2 ("arm64: kdump: Remove custom linux,usable-memory-range handling") > Signed-off-by: Pingfan Liu <kernelfans@gmail.com> > Cc: Rob Herring <robh+dt@kernel.org> > Cc: Zhen Lei <thunder.leizhen@huawei.com> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Will Deacon <will@kernel.org> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Mike Rapoport <rppt@kernel.org> > Cc: Geert Uytterhoeven <geert+renesas@glider.be> > Cc: Frank Rowand <frowand.list@gmail.com> > Cc: Ard Biesheuvel <ardb@kernel.org> > Cc: Nick Terrell <terrelln@fb.com> > Cc: linux-arm-kernel@lists.infradead.org > To: devicetree@vger.kernel.org > To: linux-efi@vger.kernel.org > --- > v2 -> v3: > use static inline stub to avoid #ifdef according to Rob's suggestion > > drivers/firmware/efi/efi-init.c | 5 +++++ > drivers/of/fdt.c | 2 +- > include/linux/of_fdt.h | 2 ++ > 3 files changed, 8 insertions(+), 1 deletion(-) > Applied, thanks!
On 2021/12/15 10:13, Pingfan Liu wrote: > > diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c > index 18a2df431bfd..aa07ef5cab5f 100644 > --- a/drivers/of/fdt.c > +++ b/drivers/of/fdt.c > @@ -972,7 +972,7 @@ static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND; > * location from flat tree > * @node: reference to node containing usable memory range location ('chosen') > */ > -static void __init early_init_dt_check_for_usable_mem_range(void) > +void __init early_init_dt_check_for_usable_mem_range(void) Why do I see a parameter 'node'? master: drivers/of/fdt.c:976:static void __init early_init_dt_check_for_usable_mem_range(unsigned long node) next: drivers/of/fdt.c:980:static void __init early_init_dt_check_for_usable_mem_range(unsigned long node) > { > const __be32 *prop; > int len; > diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h > index cf48983d3c86..ad09beb6d13c 100644 > --- a/include/linux/of_fdt.h > +++ b/include/linux/of_fdt.h > @@ -62,6 +62,7 @@ extern int early_init_dt_scan_chosen(unsigned long node, const char *uname, > int depth, void *data); > extern int early_init_dt_scan_memory(unsigned long node, const char *uname, > int depth, void *data); > +extern void early_init_dt_check_for_usable_mem_range(void); > extern int early_init_dt_scan_chosen_stdout(void); > extern void early_init_fdt_scan_reserved_mem(void); > extern void early_init_fdt_reserve_self(void); > @@ -86,6 +87,7 @@ extern void unflatten_and_copy_device_tree(void); > extern void early_init_devtree(void *); > extern void early_get_first_memblock_info(void *, phys_addr_t *); > #else /* CONFIG_OF_EARLY_FLATTREE */ > +static inline void early_init_dt_check_for_usable_mem_range(void) {} > static inline int early_init_dt_scan_chosen_stdout(void) { return -ENODEV; } > static inline void early_init_fdt_scan_reserved_mem(void) {} > static inline void early_init_fdt_reserve_self(void) {} >
On 2021/12/22 16:00, Leizhen (ThunderTown) wrote: > > > On 2021/12/15 10:13, Pingfan Liu wrote: >> >> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c >> index 18a2df431bfd..aa07ef5cab5f 100644 >> --- a/drivers/of/fdt.c >> +++ b/drivers/of/fdt.c >> @@ -972,7 +972,7 @@ static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND; >> * location from flat tree >> * @node: reference to node containing usable memory range location ('chosen') >> */ >> -static void __init early_init_dt_check_for_usable_mem_range(void) >> +void __init early_init_dt_check_for_usable_mem_range(void) > > Why do I see a parameter 'node'? Sorry, I just saw that the patch 1/2 in v2 was also applied. > > master: > drivers/of/fdt.c:976:static void __init early_init_dt_check_for_usable_mem_range(unsigned long node) > > next: > drivers/of/fdt.c:980:static void __init early_init_dt_check_for_usable_mem_range(unsigned long node) > >> { >> const __be32 *prop; >> int len; >> diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h >> index cf48983d3c86..ad09beb6d13c 100644 >> --- a/include/linux/of_fdt.h >> +++ b/include/linux/of_fdt.h >> @@ -62,6 +62,7 @@ extern int early_init_dt_scan_chosen(unsigned long node, const char *uname, >> int depth, void *data); >> extern int early_init_dt_scan_memory(unsigned long node, const char *uname, >> int depth, void *data); >> +extern void early_init_dt_check_for_usable_mem_range(void); >> extern int early_init_dt_scan_chosen_stdout(void); >> extern void early_init_fdt_scan_reserved_mem(void); >> extern void early_init_fdt_reserve_self(void); >> @@ -86,6 +87,7 @@ extern void unflatten_and_copy_device_tree(void); >> extern void early_init_devtree(void *); >> extern void early_get_first_memblock_info(void *, phys_addr_t *); >> #else /* CONFIG_OF_EARLY_FLATTREE */ >> +static inline void early_init_dt_check_for_usable_mem_range(void) {} >> static inline int early_init_dt_scan_chosen_stdout(void) { return -ENODEV; } >> static inline void early_init_fdt_scan_reserved_mem(void) {} >> static inline void early_init_fdt_reserve_self(void) {} >>
diff --git a/drivers/firmware/efi/efi-init.c b/drivers/firmware/efi/efi-init.c index b19ce1a83f91..b2c829e95bd1 100644 --- a/drivers/firmware/efi/efi-init.c +++ b/drivers/firmware/efi/efi-init.c @@ -235,6 +235,11 @@ void __init efi_init(void) } reserve_regions(); + /* + * For memblock manipulation, the cap should come after the memblock_add(). + * And now, memblock is fully populated, it is time to do capping. + */ + early_init_dt_check_for_usable_mem_range(); efi_esrt_init(); efi_mokvar_table_init(); diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 18a2df431bfd..aa07ef5cab5f 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -972,7 +972,7 @@ static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND; * location from flat tree * @node: reference to node containing usable memory range location ('chosen') */ -static void __init early_init_dt_check_for_usable_mem_range(void) +void __init early_init_dt_check_for_usable_mem_range(void) { const __be32 *prop; int len; diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h index cf48983d3c86..ad09beb6d13c 100644 --- a/include/linux/of_fdt.h +++ b/include/linux/of_fdt.h @@ -62,6 +62,7 @@ extern int early_init_dt_scan_chosen(unsigned long node, const char *uname, int depth, void *data); extern int early_init_dt_scan_memory(unsigned long node, const char *uname, int depth, void *data); +extern void early_init_dt_check_for_usable_mem_range(void); extern int early_init_dt_scan_chosen_stdout(void); extern void early_init_fdt_scan_reserved_mem(void); extern void early_init_fdt_reserve_self(void); @@ -86,6 +87,7 @@ extern void unflatten_and_copy_device_tree(void); extern void early_init_devtree(void *); extern void early_get_first_memblock_info(void *, phys_addr_t *); #else /* CONFIG_OF_EARLY_FLATTREE */ +static inline void early_init_dt_check_for_usable_mem_range(void) {} static inline int early_init_dt_scan_chosen_stdout(void) { return -ENODEV; } static inline void early_init_fdt_scan_reserved_mem(void) {} static inline void early_init_fdt_reserve_self(void) {}
On arm64, during kdump kernel saves vmcore, it runs into the following bug: ... [ 15.148919] usercopy: Kernel memory exposure attempt detected from SLUB object 'kmem_cache_node' (offset 0, size 4096)! [ 15.159707] ------------[ cut here ]------------ [ 15.164311] kernel BUG at mm/usercopy.c:99! [ 15.168482] Internal error: Oops - BUG: 0 [#1] SMP [ 15.173261] Modules linked in: xfs libcrc32c crct10dif_ce ghash_ce sha2_ce sha256_arm64 sha1_ce sbsa_gwdt ast i2c_algo_bit drm_vram_helper drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops cec drm_ttm_helper ttm drm nvme nvme_core xgene_hwmon i2c_designware_platform i2c_designware_core dm_mirror dm_region_hash dm_log dm_mod overlay squashfs zstd_decompress loop [ 15.206186] CPU: 0 PID: 542 Comm: cp Not tainted 5.16.0-rc4 #1 [ 15.212006] Hardware name: GIGABYTE R272-P30-JG/MP32-AR0-JG, BIOS F12 (SCP: 1.5.20210426) 05/13/2021 [ 15.221125] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 15.228073] pc : usercopy_abort+0x9c/0xa0 [ 15.232074] lr : usercopy_abort+0x9c/0xa0 [ 15.236070] sp : ffff8000121abba0 [ 15.239371] x29: ffff8000121abbb0 x28: 0000000000003000 x27: 0000000000000000 [ 15.246494] x26: 0000000080000400 x25: 0000ffff885c7000 x24: 0000000000000000 [ 15.253617] x23: 000007ff80400000 x22: ffff07ff80401000 x21: 0000000000000001 [ 15.260739] x20: 0000000000001000 x19: ffff07ff80400000 x18: ffffffffffffffff [ 15.267861] x17: 656a626f2042554c x16: 53206d6f72662064 x15: 6574636574656420 [ 15.274983] x14: 74706d6574746120 x13: 2129363930342065 x12: 7a6973202c302074 [ 15.282105] x11: ffffc8b041d1b148 x10: 00000000ffff8000 x9 : ffffc8b04012812c [ 15.289228] x8 : 00000000ffff7fff x7 : ffffc8b041d1b148 x6 : 0000000000000000 [ 15.296349] x5 : 0000000000000000 x4 : 0000000000007fff x3 : 0000000000000000 [ 15.303471] x2 : 0000000000000000 x1 : ffff07ff8c064800 x0 : 000000000000006b [ 15.310593] Call trace: [ 15.313027] usercopy_abort+0x9c/0xa0 [ 15.316677] __check_heap_object+0xd4/0xf0 [ 15.320762] __check_object_size.part.0+0x160/0x1e0 [ 15.325628] __check_object_size+0x2c/0x40 [ 15.329711] copy_oldmem_page+0x7c/0x140 [ 15.333623] read_from_oldmem.part.0+0xfc/0x1c0 [ 15.338142] __read_vmcore.constprop.0+0x23c/0x350 [ 15.342920] read_vmcore+0x28/0x34 [ 15.346309] proc_reg_read+0xb4/0xf0 [ 15.349871] vfs_read+0xb8/0x1f0 [ 15.353088] ksys_read+0x74/0x100 [ 15.356390] __arm64_sys_read+0x28/0x34 ... This bug introduced by commit b261dba2fdb2 ("arm64: kdump: Remove custom linux,usable-memory-range handling"), which moves memblock_cap_memory_range() to fdt, but it breaches the rules that memblock_cap_memory_range() should come after memblock_add() etc as said in commit e888fa7bb882 ("memblock: Check memory add/cap ordering"). As a consequence, the virtual address set up by copy_oldmem_page() does not bail out from the test of virt_addr_valid() in check_heap_object(), and finally hits the BUG_ON(). Since memblock allocator has no idea about when the memblock is fully populated, while efi_init() is aware, so tackling this issue by calling the interface early_init_dt_check_for_usable_mem_range() exposed by of/fdt. Fixes: b261dba2fdb2 ("arm64: kdump: Remove custom linux,usable-memory-range handling") Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Cc: Rob Herring <robh+dt@kernel.org> Cc: Zhen Lei <thunder.leizhen@huawei.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Nick Terrell <terrelln@fb.com> Cc: linux-arm-kernel@lists.infradead.org To: devicetree@vger.kernel.org To: linux-efi@vger.kernel.org --- v2 -> v3: use static inline stub to avoid #ifdef according to Rob's suggestion drivers/firmware/efi/efi-init.c | 5 +++++ drivers/of/fdt.c | 2 +- include/linux/of_fdt.h | 2 ++ 3 files changed, 8 insertions(+), 1 deletion(-)