[syzbot] [kernel?] kernel BUG in commit_creds (2)

From: syzbot
Date: Fri Apr 21 2023 - 12:20:50 EST


Hello,

syzbot found the following issue on:

HEAD commit: 6a8f57ae2eb0 Linux 6.3-rc7
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=122152afc80000
kernel config: https://syzkaller.appspot.com/x/.config?x=4afb87f3ec27b7fd
dashboard link: https://syzkaller.appspot.com/bug?extid=57f29dd5bfc4c89532f9
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/da19cc95d265/disk-6a8f57ae.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/508e5ccb6948/vmlinux-6a8f57ae.xz
kernel image: https://storage.googleapis.com/syzbot-assets/aa14910af715/bzImage-6a8f57ae.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+57f29dd5bfc4c89532f9@xxxxxxxxxxxxxxxxxxxxxxxxx

------------[ cut here ]------------
kernel BUG at kernel/cred.c:456!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 7314 Comm: iou-wrk-7310 Not tainted 6.3.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023
RIP: 0010:commit_creds+0x11fc/0x1210 kernel/cred.c:456
Code: f9 ff ff 48 8b 4c 24 18 80 e1 07 80 c1 03 38 c1 0f 8c 99 f9 ff ff 48 8b 7c 24 18 e8 4e 60 83 00 e9 8a f9 ff ff e8 b4 9f 2d 00 <0f> 0b e8 ad 9f 2d 00 0f 0b e8 a6 9f 2d 00 0f 0b 0f 1f 40 00 f3 0f
RSP: 0018:ffffc90014fdf758 EFLAGS: 00010293
RAX: ffffffff815cd70c RBX: ffff88807e7cd7c0 RCX: ffff88807e7cd7c0
RDX: 0000000000000000 RSI: ffffffff8aea7d00 RDI: ffff888021df9500
RBP: ffff88807e7cdfb8 R08: dffffc0000000000 R09: fffffbfff1ca6946
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88807e7cdfb0
R13: dffffc0000000000 R14: ffff88801e3fdd00 R15: 1ffff11004dc6098
FS: 00007feb6d00b700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f795b584558 CR3: 000000001f493000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
smk_write_relabel_self+0x4d7/0x540 security/smack/smackfs.c:2798
loop_rw_iter+0x35c/0x590
io_write+0xebf/0x1340 io_uring/rw.c:923
io_issue_sqe+0x2f0/0xb20 io_uring/io_uring.c:1907
io_wq_submit_work+0x41a/0x800 io_uring/io_uring.c:1983
io_worker_handle_work+0x817/0xd90 io_uring/io-wq.c:587
io_wqe_worker+0x3d1/0xe00 io_uring/io-wq.c:632
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:commit_creds+0x11fc/0x1210 kernel/cred.c:456
Code: f9 ff ff 48 8b 4c 24 18 80 e1 07 80 c1 03 38 c1 0f 8c 99 f9 ff ff 48 8b 7c 24 18 e8 4e 60 83 00 e9 8a f9 ff ff e8 b4 9f 2d 00 <0f> 0b e8 ad 9f 2d 00 0f 0b e8 a6 9f 2d 00 0f 0b 0f 1f 40 00 f3 0f
RSP: 0018:ffffc90014fdf758 EFLAGS: 00010293
RAX: ffffffff815cd70c RBX: ffff88807e7cd7c0 RCX: ffff88807e7cd7c0
RDX: 0000000000000000 RSI: ffffffff8aea7d00 RDI: ffff888021df9500
RBP: ffff88807e7cdfb8 R08: dffffc0000000000 R09: fffffbfff1ca6946
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88807e7cdfb0
R13: dffffc0000000000 R14: ffff88801e3fdd00 R15: 1ffff11004dc6098
FS: 00007feb6d00b700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31d21000 CR3: 000000001f493000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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