| Message ID | tencent_B2753AAC8B944F98A6F9387CECDEEBDA210A@qq.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | pstore: Fix uaf when backend is unregistered | expand |
On Sun, Sep 29, 2024 at 08:43:37PM +0800, Li XingYang wrote: I have another idea to fix this issue, which is to no longer use pstore_put_mackend_records to release dentry, but instead to add the reference count of the pstore backend driver when mounting pstore using try_rodule_get to avoid uninstalling the backend driver during mounting, just like other file systems. However, it seems that a lot of things need to be changed. > when unload pstore_blk, we will unlink the pstore file and > set pos->dentry to NULL, but simple_unlink(d_inode(root), pos->dentry) > may free inode of pos->dentry and free pos by free_pstore_private, > this may trigger uaf. kasan report: > > kernel: ================================================================== > kernel: BUG: KASAN: slab-use-after-free in pstore_put_backend_records+0x3a4/0x480 > kernel: Write of size 8 at addr ffff8883efbe0390 by task modprobe/4308 > kernel: > kernel: CPU: 1 PID: 4308 Comm: modprobe Kdump: loaded Not tainted 6.10.9-arch1-2 #2 5fd36c90225554e2cc88363729bd91e76130a89f > kernel: Hardware name: ASUS System Product Name/TUF GAMING X670E-PLUS, BIOS 3024 08/02/2024 > kernel: Call Trace: > kernel: <TASK> > kernel: dump_stack_lvl+0x5d/0x80 > kernel: print_report+0x174/0x505 > kernel: ? __pfx__raw_spin_lock_irqsave+0x10/0x10 > kernel: ? pstore_put_backend_records+0x3a4/0x480 > kernel: kasan_report+0xd0/0x150 > kernel: ? pstore_put_backend_records+0x3a4/0x480 > kernel: pstore_put_backend_records+0x3a4/0x480 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: pstore_unregister+0x88/0x1b0 > kernel: unregister_pstore_zone+0x2f/0xd0 [pstore_zone 35171c701a99c31efe207b7a718dc583e4a6503a] > kernel: pstore_blk_exit+0x30/0x90 [pstore_blk 589d82101219208d8968e3adda9b96a2d42df635] > kernel: __do_sys_delete_module+0x350/0x560 > kernel: ? __pfx___do_sys_delete_module+0x10/0x10 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? __memcg_slab_free_hook+0x28e/0x470 > kernel: ? __pfx___audit_syscall_exit+0x10/0x10 > kernel: do_syscall_64+0x82/0x190 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? do_syscall_64+0x8e/0x190 > kernel: ? seq_read_iter+0x62f/0x1220 > kernel: ? __x64_sys_openat+0x300/0x380 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? kasan_save_track+0x14/0x30 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? vfs_read+0x9a7/0xf00 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? __audit_syscall_exit+0x38a/0x520 > kernel: ? __pfx_vfs_read+0x10/0x10 > kernel: ? __pfx___audit_syscall_exit+0x10/0x10 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? __audit_syscall_exit+0x38a/0x520 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? __pfx___audit_syscall_exit+0x10/0x10 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? __x64_sys_read+0x162/0x250 > kernel: ? __pfx___x64_sys_read+0x10/0x10 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? syscall_exit_to_user_mode_prepare+0x148/0x170 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? syscall_exit_to_user_mode+0x73/0x1f0 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? do_syscall_64+0x8e/0x190 > kernel: ? syscall_exit_to_user_mode+0x73/0x1f0 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: entry_SYSCALL_64_after_hwframe+0x76/0x7e > kernel: RIP: 0033:0x741f9d72946b > kernel: Code: 73 01 c3 48 8b 0d a5 c8 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 75 c8 0c 00 f7 d8 64 89 01 48 > kernel: RSP: 002b:00007ffed7e621f8 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 > kernel: RAX: ffffffffffffffda RBX: 00006455e060ed30 RCX: 0000741f9d72946b > kernel: RDX: 0000000000000000 RSI: 0000000000000800 RDI: 00006455e060ed98 > kernel: RBP: 00007ffed7e62220 R08: 1999999999999999 R09: 0000000000000000 > kernel: R10: 0000741f9d7a5fe0 R11: 0000000000000206 R12: 0000000000000000 > kernel: R13: 00007ffed7e62250 R14: 0000000000000000 R15: 0000000000000000 > kernel: </TASK> > kernel: > kernel: Allocated by task 3957: > kernel: kasan_save_stack+0x30/0x50 > kernel: kasan_save_track+0x14/0x30 > kernel: __kasan_kmalloc+0xaa/0xb0 > kernel: pstore_mkfile+0x47e/0xbe0 > kernel: pstore_get_backend_records+0x560/0x920 > kernel: pstore_get_records+0xec/0x180 > kernel: pstore_register+0x1c3/0x5a0 > kernel: register_pstore_zone.cold+0x298/0x3d1 [pstore_zone] > kernel: pstore_blk_init+0x63c/0xff0 [pstore_blk] > kernel: do_one_initcall+0xa4/0x380 > kernel: do_init_module+0x28a/0x7c0 > kernel: load_module+0x7b57/0xb020 > kernel: init_module_from_file+0xdf/0x150 > kernel: idempotent_init_module+0x23c/0x780 > kernel: __x64_sys_finit_module+0xbe/0x130 > kernel: do_syscall_64+0x82/0x190 > kernel: entry_SYSCALL_64_after_hwframe+0x76/0x7e > kernel: > kernel: Freed by task 4308: > kernel: kasan_save_stack+0x30/0x50 > kernel: kasan_save_track+0x14/0x30 > kernel: kasan_save_free_info+0x3b/0x60 > kernel: __kasan_slab_free+0x12c/0x1b0 > kernel: kfree+0x198/0x3b0 > kernel: evict+0x33d/0xab0 > kernel: __dentry_kill+0x17f/0x590 > kernel: dput+0x2d9/0x810 > kernel: simple_unlink+0xf4/0x140 > kernel: pstore_put_backend_records+0x271/0x480 > kernel: pstore_unregister+0x88/0x1b0 > kernel: unregister_pstore_zone+0x2f/0xd0 [pstore_zone] > kernel: pstore_blk_exit+0x30/0x90 [pstore_blk] > kernel: __do_sys_delete_module+0x350/0x560 > kernel: do_syscall_64+0x82/0x190 > kernel: entry_SYSCALL_64_after_hwframe+0x76/0x7e > kernel: > kernel: The buggy address belongs to the object at ffff8883efbe0380 > which belongs to the cache kmalloc-64 of size 64 > kernel: The buggy address is located 16 bytes inside of > freed 64-byte region [ffff8883efbe0380, ffff8883efbe03c0) > kernel: > kernel: The buggy address belongs to the physical page: > kernel: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3efbe0 > kernel: memcg:ffff8883ef245801 > kernel: flags: 0x2ffff8000000000(node=0|zone=2|lastcpupid=0x1ffff) > kernel: page_type: 0xffffefff(slab) > kernel: raw: 02ffff8000000000 ffff88810004c8c0 ffffea00043dcc40 dead000000000004 > kernel: raw: 0000000000000000 0000000000200020 00000001ffffefff ffff8883ef245801 > kernel: page dumped because: kasan: bad access detected > kernel: > kernel: Memory state around the buggy address: > kernel: ffff8883efbe0280: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > kernel: ffff8883efbe0300: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc > kernel: >ffff8883efbe0380: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > kernel: ^ > kernel: ffff8883efbe0400: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > kernel: ffff8883efbe0480: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc > kernel: ================================================================== > kernel: Disabling lock debugging due to kernel taint > kernel: pstore: Unregistered pstore_blk as persistent store backend > kernel: ------------[ cut here ]------------ > > place the pos->dentry = NULL before simple_unlink(d_inode(root), pos->dentry) > > Fixes: 609e28bb139e ("pstore: Remove filesystem records when backend is unregistered") > Signed-off-by: Li XingYang <lixingyang1@qq.com> > Signed-off-by: Zach Wade <zachwade.k@gmail.com> > --- > fs/pstore/inode.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c > index 56815799ce79..7561693e0f32 100644 > --- a/fs/pstore/inode.c > +++ b/fs/pstore/inode.c > @@ -306,7 +306,7 @@ static struct dentry *psinfo_lock_root(void) > int pstore_put_backend_records(struct pstore_info *psi) > { > struct pstore_private *pos, *tmp; > - struct dentry *root; > + struct dentry *root, *unlink_dentry; > > root = psinfo_lock_root(); > if (!root) > @@ -316,9 +316,10 @@ int pstore_put_backend_records(struct pstore_info *psi) > list_for_each_entry_safe(pos, tmp, &records_list, list) { > if (pos->record->psi == psi) { > list_del_init(&pos->list); > - d_invalidate(pos->dentry); > - simple_unlink(d_inode(root), pos->dentry); > + unlink_dentry = pos->dentry; > pos->dentry = NULL; > + d_invalidate(unlink_dentry); > + simple_unlink(d_inode(root), unlink_dentry); > } > } > } > -- > 2.46.2
On Sun, Sep 29, 2024 at 08:43:37PM +0800, Li XingYang wrote: > when unload pstore_blk, we will unlink the pstore file and > set pos->dentry to NULL, but simple_unlink(d_inode(root), pos->dentry) > may free inode of pos->dentry and free pos by free_pstore_private, > this may trigger uaf. kasan report: > > kernel: ================================================================== > kernel: BUG: KASAN: slab-use-after-free in pstore_put_backend_records+0x3a4/0x480 > kernel: Write of size 8 at addr ffff8883efbe0390 by task modprobe/4308 > kernel: > kernel: CPU: 1 PID: 4308 Comm: modprobe Kdump: loaded Not tainted 6.10.9-arch1-2 #2 5fd36c90225554e2cc88363729bd91e76130a89f > kernel: Hardware name: ASUS System Product Name/TUF GAMING X670E-PLUS, BIOS 3024 08/02/2024 > kernel: Call Trace: > kernel: <TASK> > kernel: dump_stack_lvl+0x5d/0x80 > kernel: print_report+0x174/0x505 > kernel: ? __pfx__raw_spin_lock_irqsave+0x10/0x10 > kernel: ? pstore_put_backend_records+0x3a4/0x480 > kernel: kasan_report+0xd0/0x150 > kernel: ? pstore_put_backend_records+0x3a4/0x480 > kernel: pstore_put_backend_records+0x3a4/0x480 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: pstore_unregister+0x88/0x1b0 > kernel: unregister_pstore_zone+0x2f/0xd0 [pstore_zone 35171c701a99c31efe207b7a718dc583e4a6503a] > kernel: pstore_blk_exit+0x30/0x90 [pstore_blk 589d82101219208d8968e3adda9b96a2d42df635] > kernel: __do_sys_delete_module+0x350/0x560 > kernel: ? __pfx___do_sys_delete_module+0x10/0x10 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? __memcg_slab_free_hook+0x28e/0x470 > kernel: ? __pfx___audit_syscall_exit+0x10/0x10 > kernel: do_syscall_64+0x82/0x190 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? do_syscall_64+0x8e/0x190 > kernel: ? seq_read_iter+0x62f/0x1220 > kernel: ? __x64_sys_openat+0x300/0x380 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? kasan_save_track+0x14/0x30 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? vfs_read+0x9a7/0xf00 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? __audit_syscall_exit+0x38a/0x520 > kernel: ? __pfx_vfs_read+0x10/0x10 > kernel: ? __pfx___audit_syscall_exit+0x10/0x10 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? __audit_syscall_exit+0x38a/0x520 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? __pfx___audit_syscall_exit+0x10/0x10 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? __x64_sys_read+0x162/0x250 > kernel: ? __pfx___x64_sys_read+0x10/0x10 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? syscall_exit_to_user_mode_prepare+0x148/0x170 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? syscall_exit_to_user_mode+0x73/0x1f0 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? do_syscall_64+0x8e/0x190 > kernel: ? syscall_exit_to_user_mode+0x73/0x1f0 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: ? srso_alias_return_thunk+0x5/0xfbef5 > kernel: entry_SYSCALL_64_after_hwframe+0x76/0x7e > kernel: RIP: 0033:0x741f9d72946b > kernel: Code: 73 01 c3 48 8b 0d a5 c8 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 75 c8 0c 00 f7 d8 64 89 01 48 > kernel: RSP: 002b:00007ffed7e621f8 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 > kernel: RAX: ffffffffffffffda RBX: 00006455e060ed30 RCX: 0000741f9d72946b > kernel: RDX: 0000000000000000 RSI: 0000000000000800 RDI: 00006455e060ed98 > kernel: RBP: 00007ffed7e62220 R08: 1999999999999999 R09: 0000000000000000 > kernel: R10: 0000741f9d7a5fe0 R11: 0000000000000206 R12: 0000000000000000 > kernel: R13: 00007ffed7e62250 R14: 0000000000000000 R15: 0000000000000000 > kernel: </TASK> > kernel: > kernel: Allocated by task 3957: > kernel: kasan_save_stack+0x30/0x50 > kernel: kasan_save_track+0x14/0x30 > kernel: __kasan_kmalloc+0xaa/0xb0 > kernel: pstore_mkfile+0x47e/0xbe0 > kernel: pstore_get_backend_records+0x560/0x920 > kernel: pstore_get_records+0xec/0x180 > kernel: pstore_register+0x1c3/0x5a0 > kernel: register_pstore_zone.cold+0x298/0x3d1 [pstore_zone] > kernel: pstore_blk_init+0x63c/0xff0 [pstore_blk] > kernel: do_one_initcall+0xa4/0x380 > kernel: do_init_module+0x28a/0x7c0 > kernel: load_module+0x7b57/0xb020 > kernel: init_module_from_file+0xdf/0x150 > kernel: idempotent_init_module+0x23c/0x780 > kernel: __x64_sys_finit_module+0xbe/0x130 > kernel: do_syscall_64+0x82/0x190 > kernel: entry_SYSCALL_64_after_hwframe+0x76/0x7e > kernel: > kernel: Freed by task 4308: > kernel: kasan_save_stack+0x30/0x50 > kernel: kasan_save_track+0x14/0x30 > kernel: kasan_save_free_info+0x3b/0x60 > kernel: __kasan_slab_free+0x12c/0x1b0 > kernel: kfree+0x198/0x3b0 > kernel: evict+0x33d/0xab0 > kernel: __dentry_kill+0x17f/0x590 > kernel: dput+0x2d9/0x810 > kernel: simple_unlink+0xf4/0x140 > kernel: pstore_put_backend_records+0x271/0x480 > kernel: pstore_unregister+0x88/0x1b0 > kernel: unregister_pstore_zone+0x2f/0xd0 [pstore_zone] > kernel: pstore_blk_exit+0x30/0x90 [pstore_blk] > kernel: __do_sys_delete_module+0x350/0x560 > kernel: do_syscall_64+0x82/0x190 > kernel: entry_SYSCALL_64_after_hwframe+0x76/0x7e > kernel: > kernel: The buggy address belongs to the object at ffff8883efbe0380 > which belongs to the cache kmalloc-64 of size 64 > kernel: The buggy address is located 16 bytes inside of > freed 64-byte region [ffff8883efbe0380, ffff8883efbe03c0) > kernel: > kernel: The buggy address belongs to the physical page: > kernel: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3efbe0 > kernel: memcg:ffff8883ef245801 > kernel: flags: 0x2ffff8000000000(node=0|zone=2|lastcpupid=0x1ffff) > kernel: page_type: 0xffffefff(slab) > kernel: raw: 02ffff8000000000 ffff88810004c8c0 ffffea00043dcc40 dead000000000004 > kernel: raw: 0000000000000000 0000000000200020 00000001ffffefff ffff8883ef245801 > kernel: page dumped because: kasan: bad access detected > kernel: > kernel: Memory state around the buggy address: > kernel: ffff8883efbe0280: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > kernel: ffff8883efbe0300: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc > kernel: >ffff8883efbe0380: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > kernel: ^ > kernel: ffff8883efbe0400: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > kernel: ffff8883efbe0480: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc > kernel: ================================================================== > kernel: Disabling lock debugging due to kernel taint > kernel: pstore: Unregistered pstore_blk as persistent store backend > kernel: ------------[ cut here ]------------ > > place the pos->dentry = NULL before simple_unlink(d_inode(root), pos->dentry) > > Fixes: 609e28bb139e ("pstore: Remove filesystem records when backend is unregistered") > Signed-off-by: Li XingYang <lixingyang1@qq.com> > Signed-off-by: Zach Wade <zachwade.k@gmail.com> > --- > fs/pstore/inode.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) Hi, This is the friendly patch-bot of Greg Kroah-Hartman. You have sent him a patch that has triggered this response. He used to manually respond to these common problems, but in order to save his sanity (he kept writing the same thing over and over, yet to different people), I was created. Hopefully you will not take offence and will fix the problem in your patch and resubmit it so that it can be accepted into the Linux kernel tree. You are receiving this message because of the following common error(s) as indicated below: - You have marked a patch with a "Fixes:" tag for a commit that is in an older released kernel, yet you do not have a cc: stable line in the signed-off-by area at all, which means that the patch will not be applied to any older kernel releases. To properly fix this, please follow the documented rules in the Documentation/process/stable-kernel-rules.rst file for how to resolve this. If you wish to discuss this problem further, or you have questions about how to resolve this issue, please feel free to respond to this email and Greg will reply once he has dug out from the pending patches received from other developers. thanks, greg k-h's patch email bot
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c index 56815799ce79..7561693e0f32 100644 --- a/fs/pstore/inode.c +++ b/fs/pstore/inode.c @@ -306,7 +306,7 @@ static struct dentry *psinfo_lock_root(void) int pstore_put_backend_records(struct pstore_info *psi) { struct pstore_private *pos, *tmp; - struct dentry *root; + struct dentry *root, *unlink_dentry; root = psinfo_lock_root(); if (!root) @@ -316,9 +316,10 @@ int pstore_put_backend_records(struct pstore_info *psi) list_for_each_entry_safe(pos, tmp, &records_list, list) { if (pos->record->psi == psi) { list_del_init(&pos->list); - d_invalidate(pos->dentry); - simple_unlink(d_inode(root), pos->dentry); + unlink_dentry = pos->dentry; pos->dentry = NULL; + d_invalidate(unlink_dentry); + simple_unlink(d_inode(root), unlink_dentry); } } }
when unload pstore_blk, we will unlink the pstore file and set pos->dentry to NULL, but simple_unlink(d_inode(root), pos->dentry) may free inode of pos->dentry and free pos by free_pstore_private, this may trigger uaf. kasan report: kernel: ================================================================== kernel: BUG: KASAN: slab-use-after-free in pstore_put_backend_records+0x3a4/0x480 kernel: Write of size 8 at addr ffff8883efbe0390 by task modprobe/4308 kernel: kernel: CPU: 1 PID: 4308 Comm: modprobe Kdump: loaded Not tainted 6.10.9-arch1-2 #2 5fd36c90225554e2cc88363729bd91e76130a89f kernel: Hardware name: ASUS System Product Name/TUF GAMING X670E-PLUS, BIOS 3024 08/02/2024 kernel: Call Trace: kernel: <TASK> kernel: dump_stack_lvl+0x5d/0x80 kernel: print_report+0x174/0x505 kernel: ? __pfx__raw_spin_lock_irqsave+0x10/0x10 kernel: ? pstore_put_backend_records+0x3a4/0x480 kernel: kasan_report+0xd0/0x150 kernel: ? pstore_put_backend_records+0x3a4/0x480 kernel: pstore_put_backend_records+0x3a4/0x480 kernel: ? srso_alias_return_thunk+0x5/0xfbef5 kernel: pstore_unregister+0x88/0x1b0 kernel: unregister_pstore_zone+0x2f/0xd0 [pstore_zone 35171c701a99c31efe207b7a718dc583e4a6503a] kernel: pstore_blk_exit+0x30/0x90 [pstore_blk 589d82101219208d8968e3adda9b96a2d42df635] kernel: __do_sys_delete_module+0x350/0x560 kernel: ? __pfx___do_sys_delete_module+0x10/0x10 kernel: ? srso_alias_return_thunk+0x5/0xfbef5 kernel: ? __memcg_slab_free_hook+0x28e/0x470 kernel: ? __pfx___audit_syscall_exit+0x10/0x10 kernel: do_syscall_64+0x82/0x190 kernel: ? srso_alias_return_thunk+0x5/0xfbef5 kernel: ? do_syscall_64+0x8e/0x190 kernel: ? seq_read_iter+0x62f/0x1220 kernel: ? __x64_sys_openat+0x300/0x380 kernel: ? srso_alias_return_thunk+0x5/0xfbef5 kernel: ? kasan_save_track+0x14/0x30 kernel: ? srso_alias_return_thunk+0x5/0xfbef5 kernel: ? srso_alias_return_thunk+0x5/0xfbef5 kernel: ? vfs_read+0x9a7/0xf00 kernel: ? srso_alias_return_thunk+0x5/0xfbef5 kernel: ? __audit_syscall_exit+0x38a/0x520 kernel: ? __pfx_vfs_read+0x10/0x10 kernel: ? __pfx___audit_syscall_exit+0x10/0x10 kernel: ? srso_alias_return_thunk+0x5/0xfbef5 kernel: ? __audit_syscall_exit+0x38a/0x520 kernel: ? srso_alias_return_thunk+0x5/0xfbef5 kernel: ? __pfx___audit_syscall_exit+0x10/0x10 kernel: ? srso_alias_return_thunk+0x5/0xfbef5 kernel: ? __x64_sys_read+0x162/0x250 kernel: ? __pfx___x64_sys_read+0x10/0x10 kernel: ? srso_alias_return_thunk+0x5/0xfbef5 kernel: ? syscall_exit_to_user_mode_prepare+0x148/0x170 kernel: ? srso_alias_return_thunk+0x5/0xfbef5 kernel: ? syscall_exit_to_user_mode+0x73/0x1f0 kernel: ? srso_alias_return_thunk+0x5/0xfbef5 kernel: ? do_syscall_64+0x8e/0x190 kernel: ? syscall_exit_to_user_mode+0x73/0x1f0 kernel: ? srso_alias_return_thunk+0x5/0xfbef5 kernel: ? srso_alias_return_thunk+0x5/0xfbef5 kernel: entry_SYSCALL_64_after_hwframe+0x76/0x7e kernel: RIP: 0033:0x741f9d72946b kernel: Code: 73 01 c3 48 8b 0d a5 c8 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 75 c8 0c 00 f7 d8 64 89 01 48 kernel: RSP: 002b:00007ffed7e621f8 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 kernel: RAX: ffffffffffffffda RBX: 00006455e060ed30 RCX: 0000741f9d72946b kernel: RDX: 0000000000000000 RSI: 0000000000000800 RDI: 00006455e060ed98 kernel: RBP: 00007ffed7e62220 R08: 1999999999999999 R09: 0000000000000000 kernel: R10: 0000741f9d7a5fe0 R11: 0000000000000206 R12: 0000000000000000 kernel: R13: 00007ffed7e62250 R14: 0000000000000000 R15: 0000000000000000 kernel: </TASK> kernel: kernel: Allocated by task 3957: kernel: kasan_save_stack+0x30/0x50 kernel: kasan_save_track+0x14/0x30 kernel: __kasan_kmalloc+0xaa/0xb0 kernel: pstore_mkfile+0x47e/0xbe0 kernel: pstore_get_backend_records+0x560/0x920 kernel: pstore_get_records+0xec/0x180 kernel: pstore_register+0x1c3/0x5a0 kernel: register_pstore_zone.cold+0x298/0x3d1 [pstore_zone] kernel: pstore_blk_init+0x63c/0xff0 [pstore_blk] kernel: do_one_initcall+0xa4/0x380 kernel: do_init_module+0x28a/0x7c0 kernel: load_module+0x7b57/0xb020 kernel: init_module_from_file+0xdf/0x150 kernel: idempotent_init_module+0x23c/0x780 kernel: __x64_sys_finit_module+0xbe/0x130 kernel: do_syscall_64+0x82/0x190 kernel: entry_SYSCALL_64_after_hwframe+0x76/0x7e kernel: kernel: Freed by task 4308: kernel: kasan_save_stack+0x30/0x50 kernel: kasan_save_track+0x14/0x30 kernel: kasan_save_free_info+0x3b/0x60 kernel: __kasan_slab_free+0x12c/0x1b0 kernel: kfree+0x198/0x3b0 kernel: evict+0x33d/0xab0 kernel: __dentry_kill+0x17f/0x590 kernel: dput+0x2d9/0x810 kernel: simple_unlink+0xf4/0x140 kernel: pstore_put_backend_records+0x271/0x480 kernel: pstore_unregister+0x88/0x1b0 kernel: unregister_pstore_zone+0x2f/0xd0 [pstore_zone] kernel: pstore_blk_exit+0x30/0x90 [pstore_blk] kernel: __do_sys_delete_module+0x350/0x560 kernel: do_syscall_64+0x82/0x190 kernel: entry_SYSCALL_64_after_hwframe+0x76/0x7e kernel: kernel: The buggy address belongs to the object at ffff8883efbe0380 which belongs to the cache kmalloc-64 of size 64 kernel: The buggy address is located 16 bytes inside of freed 64-byte region [ffff8883efbe0380, ffff8883efbe03c0) kernel: kernel: The buggy address belongs to the physical page: kernel: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3efbe0 kernel: memcg:ffff8883ef245801 kernel: flags: 0x2ffff8000000000(node=0|zone=2|lastcpupid=0x1ffff) kernel: page_type: 0xffffefff(slab) kernel: raw: 02ffff8000000000 ffff88810004c8c0 ffffea00043dcc40 dead000000000004 kernel: raw: 0000000000000000 0000000000200020 00000001ffffefff ffff8883ef245801 kernel: page dumped because: kasan: bad access detected kernel: kernel: Memory state around the buggy address: kernel: ffff8883efbe0280: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc kernel: ffff8883efbe0300: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc kernel: >ffff8883efbe0380: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc kernel: ^ kernel: ffff8883efbe0400: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc kernel: ffff8883efbe0480: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc kernel: ================================================================== kernel: Disabling lock debugging due to kernel taint kernel: pstore: Unregistered pstore_blk as persistent store backend kernel: ------------[ cut here ]------------ place the pos->dentry = NULL before simple_unlink(d_inode(root), pos->dentry) Fixes: 609e28bb139e ("pstore: Remove filesystem records when backend is unregistered") Signed-off-by: Li XingYang <lixingyang1@qq.com> Signed-off-by: Zach Wade <zachwade.k@gmail.com> --- fs/pstore/inode.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)