Re: [syzbot] WARNING in do_mkdirat

From: syzbot
Date: Fri Dec 09 2022 - 14:50:50 EST


syzbot has found a reproducer for the following issue on:

HEAD commit: 0d1409e4ff08 Merge tag 'drm-fixes-2022-12-09' of git://ano..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=172b960b880000
kernel config: https://syzkaller.appspot.com/x/.config?x=d58e7fe7f9cf5e24
dashboard link: https://syzkaller.appspot.com/bug?extid=919c5a9be8433b8bf201
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=145fde33880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9ab0143f95cb/disk-0d1409e4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e574d5eaa32f/vmlinux-0d1409e4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/31109436b00b/bzImage-0d1409e4.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/5cec1c83630e/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+919c5a9be8433b8bf201@xxxxxxxxxxxxxxxxxxxxxxxxx

WARNING: CPU: 1 PID: 4982 at kernel/locking/rwsem.c:1361 __up_write kernel/locking/rwsem.c:1360 [inline]
WARNING: CPU: 1 PID: 4982 at kernel/locking/rwsem.c:1361 up_write+0x4f9/0x580 kernel/locking/rwsem.c:1615
Modules linked in:
CPU: 1 PID: 4982 Comm: syz-executor.4 Not tainted 6.1.0-rc8-syzkaller-00148-g0d1409e4ff08 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:__up_write kernel/locking/rwsem.c:1360 [inline]
RIP: 0010:up_write+0x4f9/0x580 kernel/locking/rwsem.c:1615
Code: c7 c0 a3 ed 8a 48 c7 c6 60 a6 ed 8a 48 8b 54 24 28 48 8b 4c 24 18 4d 89 e0 4c 8b 4c 24 30 31 c0 53 e8 ab 7c e8 ff 48 83 c4 08 <0f> 0b e9 6b fd ff ff 48 c7 c1 18 2a 76 8e 80 e1 07 80 c1 03 38 c1
RSP: 0018:ffffc9000564fd40 EFLAGS: 00010292
RAX: 9a2b61996b411800 RBX: ffffffff8aeda4a0 RCX: ffff88801f5d3a80
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc9000564fe10 R08: ffffffff816e5c7d R09: fffff52000ac9f61
R10: fffff52000ac9f61 R11: 1ffff92000ac9f60 R12: 0000000000000000
R13: ffff888069880a90 R14: 1ffff92000ac9fb0 R15: dffffc0000000000
FS: 00007f71b6d62700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f825d9ff000 CR3: 000000006cef1000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
inode_unlock include/linux/fs.h:761 [inline]
done_path_create fs/namei.c:3857 [inline]
do_mkdirat+0x2de/0x550 fs/namei.c:4064
__do_sys_mkdirat fs/namei.c:4076 [inline]
__se_sys_mkdirat fs/namei.c:4074 [inline]
__x64_sys_mkdirat+0x85/0x90 fs/namei.c:4074
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f71b608c0d9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f71b6d62168 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f71b61ac050 RCX: 00007f71b608c0d9
RDX: 0000000000000000 RSI: 0000000020000280 RDI: 0000000000000004
RBP: 00007f71b60e7ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffeac9136ff R14: 00007f71b6d62300 R15: 0000000000022000
</TASK>