[syzbot] [tmpfs?] WARNING in shmem_evict_inode

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 41c03ba9beea Merge tag 'for_linus' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12fa0b4c480000
kernel config: https://syzkaller.appspot.com/x/.config?x=46221e8203c7aca6
dashboard link: https://syzkaller.appspot.com/bug?extid=3d4aa0d3e784b29b1520
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: i386

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/029f81c97447/disk-41c03ba9.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/02b0f933f93e/vmlinux-41c03ba9.xz
kernel image: https://storage.googleapis.com/syzbot-assets/aa82b725810f/bzImage-41c03ba9.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3d4aa0...@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 1 PID: 1301 at mm/shmem.c:1175 shmem_evict_inode+0x873/0xb60 mm/shmem.c:1175
Modules linked in:
CPU: 0 PID: 1301 Comm: syz-executor.5 Not tainted 6.2.0-rc2-syzkaller-00057-g41c03ba9beea #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:shmem_evict_inode+0x873/0xb60 mm/shmem.c:1175
Code: 89 fe e8 50 2b cd ff 45 85 ff 75 ab e8 96 2e cd ff 48 8b 74 24 18 48 8b 7c 24 20 e8 b7 41 ac ff e9 fc fd ff ff e8 7d 2e cd ff <0f> 0b e9 a0 f8 ff ff e8 71 2e cd ff 4c 89 ea 48 b8 00 00 00 00 00
RSP: 0018:ffffc90000107830 EFLAGS: 00010293
RAX: 0000000000000000 RBX: fffffffffffffda0 RCX: 0000000000000000
RDX: ffff88807e8d57c0 RSI: ffffffff81b423e3 RDI: 0000000000000007
RBP: ffffc90000107928 R08: 0000000000000007 R09: 0000000000000000
R10: fffffffffffffda0 R11: 0000000000000000 R12: ffff88803073b378
R13: ffff88803073b3c8 R14: ffff88803073b2a8 R15: ffff88803073b2b8
FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f734d1b0 CR3: 0000000050492000 CR4: 00000000003506f0
Call Trace:
<TASK>
evict+0x2ed/0x6b0 fs/inode.c:664
iput_final fs/inode.c:1747 [inline]
iput.part.0+0x59b/0x880 fs/inode.c:1773
iput+0x5c/0x80 fs/inode.c:1763
dentry_unlink_inode+0x2b1/0x460 fs/dcache.c:401
__dentry_kill+0x3c0/0x640 fs/dcache.c:607
dentry_kill fs/dcache.c:733 [inline]
dput+0x80a/0xdb0 fs/dcache.c:913
__fput+0x3cc/0xa90 fs/file_table.c:328
task_work_run+0x16f/0x270 kernel/task_work.c:179
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0xaa8/0x2950 kernel/exit.c:867
do_group_exit+0xd4/0x2a0 kernel/exit.c:1012
get_signal+0x21c3/0x2450 kernel/signal.c:2859
arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306
exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203
__syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296
__do_fast_syscall_32+0x72/0xf0 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: 0023:0xf7fd3549
Code: Unable to access opcode bytes at 0xf7fd351f.
RSP: 002b:00000000f7fad5cc EFLAGS: 00000296 ORIG_RAX: 0000000000000004
RAX: 000000000001b000 RBX: 0000000000000006 RCX: 00000000200009c0
RDX: 00000000fffffd9d RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 3c4aa4434377 Merge tag 'ceph-for-6.4-rc1' of https://githu..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12b6d904280000
kernel config: https://syzkaller.appspot.com/x/.config?x=c1d541e02d3faec

dashboard link: https://syzkaller.appspot.com/bug?extid=3d4aa0d3e784b29b1520
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14d1973c280000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8f7290c9ee9a/disk-3c4aa443.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/750ee3ca09db/vmlinux-3c4aa443.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5839788c2cab/bzImage-3c4aa443.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3d4aa0...@syzkaller.appspotmail.com

------------[ cut here ]------------

WARNING: CPU: 0 PID: 6362 at mm/shmem.c:1186 shmem_evict_inode+0x873/0xb60 mm/shmem.c:1186
Modules linked in:
CPU: 0 PID: 6362 Comm: syz-executor.1 Not tainted 6.3.0-syzkaller-13091-g3c4aa4434377 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
RIP: 0010:shmem_evict_inode+0x873/0xb60 mm/shmem.c:1186
Code: 89 fe e8 70 1c ca ff 45 85 ff 75 ab e8 46 20 ca ff 48 8b 74 24 18 48 8b 7c 24 20 e8 a7 de a7 ff e9 fc fd ff ff e8 2d 20 ca ff <0f> 0b e9 a0 f8 ff ff e8 21 20 ca ff 4c 89 ea 48 b8 00 00 00 00 00
RSP: 0018:ffffc9000b147858 EFLAGS: 00010293
RAX: 0000000000000000 RBX: fffffffffffff840 RCX: 0000000000000000
RDX: ffff88807c94e040 RSI: ffffffff81b95ec3 RDI: 0000000000000007
RBP: ffffc9000b147950 R08: 0000000000000007 R09: 0000000000000000
R10: fffffffffffff840 R11: 0000000000000000 R12: ffff888076f85450
R13: ffff888076f854a0 R14: ffff888076f85380 R15: ffff888076f85390

FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7087f5e108 CR3: 000000007c6b6000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
evict+0x2ed/0x6b0 fs/inode.c:665
iput_final fs/inode.c:1747 [inline]
iput.part.0+0x50a/0x740 fs/inode.c:1773

iput+0x5c/0x80 fs/inode.c:1763
dentry_unlink_inode+0x2b1/0x460 fs/dcache.c:401
__dentry_kill+0x3c0/0x640 fs/dcache.c:607
dentry_kill fs/dcache.c:733 [inline]

dput+0x865/0xe10 fs/dcache.c:913
__fput+0x3cc/0xa90 fs/file_table.c:329

task_work_run+0x16f/0x270 kernel/task_work.c:179
exit_task_work include/linux/task_work.h:38 [inline]

do_exit+0xad3/0x2960 kernel/exit.c:871
do_group_exit+0xd4/0x2a0 kernel/exit.c:1021
get_signal+0x2315/0x25b0 kernel/signal.c:2874

arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306
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:286 [inline]
syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297
do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7efe7028c169
Code: Unable to access opcode bytes at 0x7efe7028c13f.
RSP: 002b:00007efe70fe2168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: 0000000000116000 RBX: 00007efe703abf80 RCX: 00007efe7028c169
RDX: 00000000fffffd2c RSI: 0000000020000000 RDI: 0000000000000004
RBP: 00007efe702e7ca1 R08: 0000000000000000 R09: 0000000000000000

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000

R13: 00007ffc607e699f R14: 00007efe70fe2300 R15: 0000000000022000
</TASK>


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

[syzbot]

syzbot has bisected this issue to:

commit 12904d953364e3bd21789a45137bf90df7cc78ee
Author: Jiaqi Yan <jiaq...@google.com>
Date: Wed Mar 29 15:11:21 2023 +0000

mm/khugepaged: recover from poisoned file-backed memory

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=14f67032280000
start commit: 3c4aa4434377 Merge tag 'ceph-for-6.4-rc1' of https://githu..
git tree: upstream
final oops: https://syzkaller.appspot.com/x/report.txt?x=16f67032280000
console output: https://syzkaller.appspot.com/x/log.txt?x=12f67032280000

kernel config: https://syzkaller.appspot.com/x/.config?x=c1d541e02d3faec
dashboard link: https://syzkaller.appspot.com/bug?extid=3d4aa0d3e784b29b1520

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14d1973c280000

Reported-by: syzbot+3d4aa0...@syzkaller.appspotmail.com
Fixes: 12904d953364 ("mm/khugepaged: recover from poisoned file-backed memory")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

[Jiaqi Yan]

It seems commit 12904d953364 caused the WARNING when MADV_COLLAPSE on
shmem memory, but right now the root cause is still unclear to me
after some digging. Will keep digging and/or try to repro over the
weekend.

[syzbot]

Auto-closing this bug as obsolete.
No recent activity, existing reproducers are no longer triggering the issue.