| Message ID | 20211213134745.43505-1-kernelfans@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: fdt: fix membock add/cap ordering | expand |
+Zhen Lei On Mon, Dec 13, 2021 at 7:48 AM Pingfan Liu <kernelfans@gmail.com> wrote: > > 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"). Presumably only when using EFI boot which throws out any DT memblock setup. > > 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 the time point of the full > memblock's population, resolving this issue at arch level code by > calling a new interface early_init_dt_cap_memory_range() exposed by fdt. > > Fixes: b261dba2fdb2 ("arm64: kdump: Remove custom linux,usable-memory-range handling") > Signed-off-by: Pingfan Liu <kernelfans@gmail.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: Rob Herring <robh+dt@kernel.org> > Cc: Frank Rowand <frowand.list@gmail.com> > Cc: Nick Terrell <terrelln@fb.com> > To: linux-arm-kernel@lists.infradead.org > To: devicetree@vger.kernel.org > --- > arch/arm64/kernel/setup.c | 1 + > drivers/of/fdt.c | 5 +++++ > include/linux/of_fdt.h | 1 + > 3 files changed, 7 insertions(+) > > diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c > index be5f85b0a24d..353e5171a66c 100644 > --- a/arch/arm64/kernel/setup.c > +++ b/arch/arm64/kernel/setup.c > @@ -331,6 +331,7 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p) > > xen_early_init(); > efi_init(); > + early_init_dt_cap_memory_range(); As it is efi_init() that does all the memblock setup, I think this belongs in efi_init() because it would be needed for any arch that uses EFI for memory setup. > > if (!efi_enabled(EFI_BOOT) && ((u64)_text % MIN_KIMG_ALIGN) != 0) > pr_warn(FW_BUG "Kernel image misaligned at boot, please fix your bootloader!"); > diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c > index bdca35284ceb..bb7e8fc3a334 100644 > --- a/drivers/of/fdt.c > +++ b/drivers/of/fdt.c > @@ -1278,6 +1278,11 @@ void __init early_init_dt_scan_nodes(void) > memblock_cap_memory_range(cap_mem_addr, cap_mem_size); > } > > +void __init early_init_dt_cap_memory_range(void) > +{ > + memblock_cap_memory_range(cap_mem_addr, cap_mem_size); This code is changing in [1] which I think should make fixing this issue easier. I'd suggest making early_init_dt_check_for_usable_mem_range() non-static and the EFI code can call it. I'm also curious how folks testing that series don't hit this issue. Rob [1] https://lore.kernel.org/all/20211210065533.2023-9-thunder.leizhen@huawei.com/
On Mon, Dec 13, 2021 at 09:31:41AM -0600, Rob Herring wrote: > +Zhen Lei > > On Mon, Dec 13, 2021 at 7:48 AM Pingfan Liu <kernelfans@gmail.com> wrote: > > > > 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"). > > Presumably only when using EFI boot which throws out any DT memblock setup. > Yes, I do think so. > > > > 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 the time point of the full > > memblock's population, resolving this issue at arch level code by > > calling a new interface early_init_dt_cap_memory_range() exposed by fdt. > > > > Fixes: b261dba2fdb2 ("arm64: kdump: Remove custom linux,usable-memory-range handling") > > Signed-off-by: Pingfan Liu <kernelfans@gmail.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: Rob Herring <robh+dt@kernel.org> > > Cc: Frank Rowand <frowand.list@gmail.com> > > Cc: Nick Terrell <terrelln@fb.com> > > To: linux-arm-kernel@lists.infradead.org > > To: devicetree@vger.kernel.org > > --- > > arch/arm64/kernel/setup.c | 1 + > > drivers/of/fdt.c | 5 +++++ > > include/linux/of_fdt.h | 1 + > > 3 files changed, 7 insertions(+) > > > > diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c > > index be5f85b0a24d..353e5171a66c 100644 > > --- a/arch/arm64/kernel/setup.c > > +++ b/arch/arm64/kernel/setup.c > > @@ -331,6 +331,7 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p) > > > > xen_early_init(); > > efi_init(); > > + early_init_dt_cap_memory_range(); > > As it is efi_init() that does all the memblock setup, I think this > belongs in efi_init() because it would be needed for any arch that > uses EFI for memory setup. > Reasonable, and efi_init() are shared by arm64 and risc-v now. > > > > if (!efi_enabled(EFI_BOOT) && ((u64)_text % MIN_KIMG_ALIGN) != 0) > > pr_warn(FW_BUG "Kernel image misaligned at boot, please fix your bootloader!"); > > diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c > > index bdca35284ceb..bb7e8fc3a334 100644 > > --- a/drivers/of/fdt.c > > +++ b/drivers/of/fdt.c > > @@ -1278,6 +1278,11 @@ void __init early_init_dt_scan_nodes(void) > > memblock_cap_memory_range(cap_mem_addr, cap_mem_size); > > } > > > > +void __init early_init_dt_cap_memory_range(void) > > +{ > > + memblock_cap_memory_range(cap_mem_addr, cap_mem_size); > > This code is changing in [1] which I think should make fixing this > issue easier. I'd suggest making > early_init_dt_check_for_usable_mem_range() non-static and the EFI code > can call it. > Thank you for the good advice. I will go in that way. > I'm also curious how folks testing that series don't hit this issue. > Maybe CONFIG_EFI=n. Thanks, Pingfan > Rob > > [1] https://lore.kernel.org/all/20211210065533.2023-9-thunder.leizhen@huawei.com/ > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index be5f85b0a24d..353e5171a66c 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -331,6 +331,7 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p) xen_early_init(); efi_init(); + early_init_dt_cap_memory_range(); if (!efi_enabled(EFI_BOOT) && ((u64)_text % MIN_KIMG_ALIGN) != 0) pr_warn(FW_BUG "Kernel image misaligned at boot, please fix your bootloader!"); diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index bdca35284ceb..bb7e8fc3a334 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -1278,6 +1278,11 @@ void __init early_init_dt_scan_nodes(void) memblock_cap_memory_range(cap_mem_addr, cap_mem_size); } +void __init early_init_dt_cap_memory_range(void) +{ + memblock_cap_memory_range(cap_mem_addr, cap_mem_size); +} + bool __init early_init_dt_scan(void *params) { bool status; diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h index cf48983d3c86..3c8a01627c02 100644 --- a/include/linux/of_fdt.h +++ b/include/linux/of_fdt.h @@ -75,6 +75,7 @@ extern int early_init_dt_scan_root(unsigned long node, const char *uname, extern bool early_init_dt_scan(void *params); extern bool early_init_dt_verify(void *params); extern void early_init_dt_scan_nodes(void); +extern void early_init_dt_cap_memory_range(void); extern const char *of_flat_dt_get_machine_name(void); extern const void *of_flat_dt_match_machine(const void *default_match,
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 the time point of the full memblock's population, resolving this issue at arch level code by calling a new interface early_init_dt_cap_memory_range() exposed by fdt. Fixes: b261dba2fdb2 ("arm64: kdump: Remove custom linux,usable-memory-range handling") Signed-off-by: Pingfan Liu <kernelfans@gmail.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: Rob Herring <robh+dt@kernel.org> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Nick Terrell <terrelln@fb.com> To: linux-arm-kernel@lists.infradead.org To: devicetree@vger.kernel.org --- arch/arm64/kernel/setup.c | 1 + drivers/of/fdt.c | 5 +++++ include/linux/of_fdt.h | 1 + 3 files changed, 7 insertions(+)