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Date:   Mon, 09 Jan 2023 09:14:40 -0800
Message-ID: <00000000000016552c05f1d7e734@google.com>
Subject: [syzbot] [tmpfs?] WARNING in shmem_evict_inode
From:   syzbot <syzbot+3d4aa0d3e784b29b1520@syzkaller.appspotmail.com>
To:     akpm@linux-foundation.org, hughd@google.com,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        syzkaller-bugs@googlegroups.com
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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+3d4aa0d3e784b29b1520@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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