merged into cifs-2.6.git for-next
Good catch
On Mon, Apr 8, 2024 at 4:32 PM Paulo Alcantara <pc@xxxxxxxxxxxxx> wrote:
>
> cifs_get_fattr() may be called with a NULL inode, so check for a
> non-NULL inode before calling
> cifs_mark_open_handles_for_deleted_file().
>
> This fixes the following oops:
>
> mount.cifs //srv/share /mnt -o ...,vers=3.1.1
> cd /mnt
> touch foo; tail -f foo &
> rm foo
> cat foo
>
> BUG: kernel NULL pointer dereference, address: 00000000000005c0
> #PF: supervisor read access in kernel mode
> #PF: error_code(0x0000) - not-present page
> PGD 0 P4D 0
> Oops: 0000 [#1] PREEMPT SMP NOPTI
> CPU: 2 PID: 696 Comm: cat Not tainted 6.9.0-rc2 #1
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
> 1.16.3-1.fc39 04/01/2014
> RIP: 0010:__lock_acquire+0x5d/0x1c70
> Code: 00 00 44 8b a4 24 a0 00 00 00 45 85 f6 0f 84 bb 06 00 00 8b 2d
> 48 e2 95 01 45 89 c3 41 89 d2 45 89 c8 85 ed 0 0 <48> 81 3f 40 7a 76
> 83 44 0f 44 d8 83 fe 01 0f 86 1b 03 00 00 31 d2
> RSP: 0018:ffffc90000b37490 EFLAGS: 00010002
> RAX: 0000000000000000 RBX: ffff888110021ec0 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000000005c0
> RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
> R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000200
> FS: 00007f2a1fa08740(0000) GS:ffff888157a00000(0000)
> knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0:
> 0000000080050033
> CR2: 00000000000005c0 CR3: 000000011ac7c000 CR4: 0000000000750ef0
> PKRU: 55555554
> Call Trace:
> <TASK>
> ? __die+0x23/0x70
> ? page_fault_oops+0x180/0x490
> ? srso_alias_return_thunk+0x5/0xfbef5
> ? exc_page_fault+0x70/0x230
> ? asm_exc_page_fault+0x26/0x30
> ? __lock_acquire+0x5d/0x1c70
> ? srso_alias_return_thunk+0x5/0xfbef5
> ? srso_alias_return_thunk+0x5/0xfbef5
> lock_acquire+0xc0/0x2d0
> ? cifs_mark_open_handles_for_deleted_file+0x3a/0x100 [cifs]
> ? srso_alias_return_thunk+0x5/0xfbef5
> ? kmem_cache_alloc+0x2d9/0x370
> _raw_spin_lock+0x34/0x80
> ? cifs_mark_open_handles_for_deleted_file+0x3a/0x100 [cifs]
> cifs_mark_open_handles_for_deleted_file+0x3a/0x100 [cifs]
> cifs_get_fattr+0x24c/0x940 [cifs]
> ? srso_alias_return_thunk+0x5/0xfbef5
> cifs_get_inode_info+0x96/0x120 [cifs]
> cifs_lookup+0x16e/0x800 [cifs]
> cifs_atomic_open+0xc7/0x5d0 [cifs]
> ? lookup_open.isra.0+0x3ce/0x5f0
> ? __pfx_cifs_atomic_open+0x10/0x10 [cifs]
> lookup_open.isra.0+0x3ce/0x5f0
> path_openat+0x42b/0xc30
> ? srso_alias_return_thunk+0x5/0xfbef5
> ? srso_alias_return_thunk+0x5/0xfbef5
> ? srso_alias_return_thunk+0x5/0xfbef5
> do_filp_open+0xc4/0x170
> do_sys_openat2+0xab/0xe0
> __x64_sys_openat+0x57/0xa0
> do_syscall_64+0xc1/0x1e0
> entry_SYSCALL_64_after_hwframe+0x72/0x7a
>
> Fixes: ffceb7640cbf ("smb: client: do not defer close open handles to deleted files")
> Signed-off-by: Paulo Alcantara (Red Hat) <pc@xxxxxxxxxxxxx>
> ---
> fs/smb/client/inode.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/fs/smb/client/inode.c b/fs/smb/client/inode.c
> index 91b07ef9e25c..60afab5c83d4 100644
> --- a/fs/smb/client/inode.c
> +++ b/fs/smb/client/inode.c
> @@ -1105,7 +1105,8 @@ static int cifs_get_fattr(struct cifs_open_info_data *data,
> } else {
> cifs_open_info_to_fattr(fattr, data, sb);
> }
> - if (!rc && fattr->cf_flags & CIFS_FATTR_DELETE_PENDING)
> + if (!rc && *inode &&
> + (fattr->cf_flags & CIFS_FATTR_DELETE_PENDING))
> cifs_mark_open_handles_for_deleted_file(*inode, full_path);
> break;
> case -EREMOTE:
> --
> 2.44.0
>
--
Thanks,
Steve
