[syzbot] [mm?] WARNING in shmem_evict_inode (2)

From: syzbot
Date: Wed Oct 04 2023 - 04:50:58 EST


Hello,

syzbot found the following issue on:

HEAD commit: 9f3ebbef746f Merge tag '6.6-rc3-ksmbd-server-fixes' of git..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1601a86e680000
kernel config: https://syzkaller.appspot.com/x/.config?x=bb54ecdfa197f132
dashboard link: https://syzkaller.appspot.com/bug?extid=511ea6c5201cd9855fea
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: i386

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-9f3ebbef.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ffda2bb1181d/vmlinux-9f3ebbef.xz
kernel image: https://storage.googleapis.com/syzbot-assets/df09a869d412/bzImage-9f3ebbef.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+511ea6c5201cd9855fea@xxxxxxxxxxxxxxxxxxxxxxxxx

------------[ cut here ]------------
WARNING: CPU: 0 PID: 15996 at mm/shmem.c:1266 shmem_evict_inode+0x871/0xb50 mm/shmem.c:1266
Modules linked in:
CPU: 0 PID: 15996 Comm: syz-executor.2 Not tainted 6.6.0-rc3-syzkaller-00146-g9f3ebbef746f #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:shmem_evict_inode+0x871/0xb50 mm/shmem.c:1266
Code: 89 e6 e8 f2 1f c7 ff 45 85 e4 75 aa e8 78 24 c7 ff 48 8b 74 24 28 48 8b 7c 24 30 e8 d9 0c a4 ff e9 1a fe ff ff e8 5f 24 c7 ff <0f> 0b e9 d3 f9 ff ff e8 53 24 c7 ff 4c 89 e2 48 b8 00 00 00 00 00
RSP: 0018:ffffc90028e0f810 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff88801e0757b0 RCX: 0000000000000000
RDX: ffff888021fa0000 RSI: ffffffff81c0a261 RDI: 0000000000000007
RBP: ffffc90028e0f940 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000000 R12: 0000000000000008
R13: 0000000000000000 R14: ffff88801e0757e0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88802c600000(0000) knlGS:0000000000000000
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f72e320e CR3: 0000000019a4e000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
evict+0x2ed/0x6b0 fs/inode.c:664
iput_final fs/inode.c:1775 [inline]
iput.part.0+0x55e/0x7a0 fs/inode.c:1801
iput+0x5c/0x80 fs/inode.c:1791
dentry_unlink_inode+0x292/0x430 fs/dcache.c:401
__dentry_kill+0x3b8/0x640 fs/dcache.c:607
dentry_kill fs/dcache.c:733 [inline]
dput+0x8b7/0xf80 fs/dcache.c:913
__fput+0x536/0xa70 fs/file_table.c:392
task_work_run+0x14d/0x240 kernel/task_work.c:180
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0xa92/0x2a20 kernel/exit.c:874
do_group_exit+0xd4/0x2a0 kernel/exit.c:1024
get_signal+0x23ba/0x2790 kernel/signal.c:2892
arch_do_signal_or_restart+0x90/0x7f0 arch/x86/kernel/signal.c:309
exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204
__syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
syscall_exit_to_user_mode+0x1d/0x60 kernel/entry/common.c:296
__do_fast_syscall_32+0x6d/0xe0 arch/x86/entry/common.c:181
do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203
entry_SYSENTER_compat_after_hwframe+0x70/0x82
RIP: 0023:0xf7f5e579
Code: Unable to access opcode bytes at 0xf7f5e54f.
RSP: 002b:00000000f7f3865c EFLAGS: 00000292 ORIG_RAX: 00000000000000f0
RAX: fffffffffffffe00 RBX: 00000000f737b050 RCX: 0000000000000080
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000f737b054
RBP: 0000000000000081 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>


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