Re: [syzbot] [ext4?] WARNING: locking bug in ext4_ioctl

From: syzbot
Date: Mon Jun 05 2023 - 02:30:01 EST


syzbot has found a reproducer for the following issue on:

HEAD commit: 9561de3a55be Linux 6.4-rc5
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=146868c9280000
kernel config: https://syzkaller.appspot.com/x/.config?x=7474de833c217bf4
dashboard link: https://syzkaller.appspot.com/bug?extid=a3c8e9ac9f9d77240afd
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14ff6e93280000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11824101280000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7890258233e8/disk-9561de3a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/693d68681275/vmlinux-9561de3a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0f62a882fdf3/bzImage-9561de3a.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/3fc2f5d70218/mount_2.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a3c8e9ac9f9d77240afd@xxxxxxxxxxxxxxxxxxxxxxxxx

------------[ cut here ]------------
Looking for class "&ei->i_data_sem" with key init_once.__key.780, but found a different class "&ei->i_data_sem" with the same key
WARNING: CPU: 1 PID: 5249 at kernel/locking/lockdep.c:941 look_up_lock_class+0xc2/0x140 kernel/locking/lockdep.c:938
Modules linked in:
CPU: 1 PID: 5249 Comm: syz-executor251 Not tainted 6.4.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
RIP: 0010:look_up_lock_class+0xc2/0x140 kernel/locking/lockdep.c:938
Code: 8b 16 48 c7 c0 60 91 1e 90 48 39 c2 74 46 f6 05 5d 02 92 03 01 75 3d c6 05 54 02 92 03 01 48 c7 c7 a0 ae ea 8a e8 de 8a a3 f6 <0f> 0b eb 26 e8 f5 d0 80 f9 48 c7 c7 e0 ad ea 8a 89 de e8 37 ca fd
RSP: 0018:ffffc900041bf590 EFLAGS: 00010046
RAX: 30aff147e011a400 RBX: ffffffff9006b360 RCX: ffff8880177bd940
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900041bf698 R08: ffffffff81530142 R09: ffffed1017325163
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000001
R13: 1ffff92000837ec0 R14: ffff888075bfc888 R15: ffffffff91cac681
FS: 0000555555be9300(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc6cdfc6138 CR3: 000000002b756000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
register_lock_class+0x104/0x990 kernel/locking/lockdep.c:1290
__lock_acquire+0xd3/0x2070 kernel/locking/lockdep.c:4965
lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5705
down_write_nested+0x3d/0x50 kernel/locking/rwsem.c:1689
swap_inode_boot_loader fs/ext4/ioctl.c:423 [inline]
__ext4_ioctl fs/ext4/ioctl.c:1418 [inline]
ext4_ioctl+0x453c/0x5b60 fs/ext4/ioctl.c:1608
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fc6cdf53a19
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdb4dc9718 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 69662f7375622f2e RCX: 00007fc6cdf53a19
RDX: 0000000000000000 RSI: 0000000000006611 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffdb4dc9740 R09: 00007ffdb4dc9740
R10: 00007ffdb4dc9190 R11: 0000000000000246 R12: 00007ffdb4dc973c
R13: 00007ffdb4dc9770 R14: 00007ffdb4dc9750 R15: 0000000000000052
</TASK>


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