From: syzbot <syzbot+e51249708aaa9b0e4d2c@syzkaller.appspotmail.com>
To: asml.silence@gmail.com, axboe@kernel.dk,
io-uring@vger.kernel.org, linux-kernel@vger.kernel.org,
syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] general protection fault in __io_file_supports_nowait
Date: Tue, 31 Aug 2021 19:00:24 -0700 [thread overview]
Message-ID: <000000000000f1f81105cae56d48@google.com> (raw)
In-Reply-To: <0000000000006d354305cae2253f@google.com>
syzbot has found a reproducer for the following issue on:
HEAD commit: b91db6a0b52e Merge tag 'for-5.15/io_uring-vfs-2021-08-30' ..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12718683300000
kernel config: https://syzkaller.appspot.com/x/.config?x=210537ff2ddcc232
dashboard link: https://syzkaller.appspot.com/bug?extid=e51249708aaa9b0e4d2c
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12615c35300000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16c57845300000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e51249708aaa9b0e4d2c@syzkaller.appspotmail.com
general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
CPU: 0 PID: 13214 Comm: iou-sqp-13213 Not tainted 5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:file_inode include/linux/fs.h:1344 [inline]
RIP: 0010:__io_file_supports_nowait+0x26/0x500 fs/io_uring.c:2785
Code: 00 00 00 00 41 55 41 54 41 89 f4 55 48 89 fd 53 e8 6f 61 96 ff 48 8d 7d 20 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 2d 04 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b
RSP: 0018:ffffc9000305f800 EFLAGS: 00010212
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffffffff81dfb791 RDI: 0000000000000020
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff81e28292 R11: 0000000000000001 R12: 0000000000000000
R13: ffffc9000305f8d8 R14: 0000000000000000 R15: 0000000000000001
FS: 00007fa1a4652700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000084 CR3: 0000000027153000 CR4: 0000000000350ef0
Call Trace:
io_file_supports_nowait fs/io_uring.c:2823 [inline]
io_file_supports_nowait fs/io_uring.c:2816 [inline]
io_read+0x4a9/0x1140 fs/io_uring.c:3440
io_issue_sqe+0x209/0x6ba0 fs/io_uring.c:6558
__io_queue_sqe+0x90/0xb50 fs/io_uring.c:6864
io_req_task_submit+0xbf/0x1b0 fs/io_uring.c:2218
tctx_task_work+0x166/0x610 fs/io_uring.c:2143
task_work_run+0xdd/0x1a0 kernel/task_work.c:164
tracehook_notify_signal include/linux/tracehook.h:212 [inline]
io_run_task_work fs/io_uring.c:2403 [inline]
io_run_task_work fs/io_uring.c:2399 [inline]
io_sq_thread+0x867/0x1370 fs/io_uring.c:7337
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Modules linked in:
---[ end trace f12dea0e85a314d8 ]---
RIP: 0010:file_inode include/linux/fs.h:1344 [inline]
RIP: 0010:__io_file_supports_nowait+0x26/0x500 fs/io_uring.c:2785
Code: 00 00 00 00 41 55 41 54 41 89 f4 55 48 89 fd 53 e8 6f 61 96 ff 48 8d 7d 20 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 2d 04 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b
RSP: 0018:ffffc9000305f800 EFLAGS: 00010212
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffffffff81dfb791 RDI: 0000000000000020
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff81e28292 R11: 0000000000000001 R12: 0000000000000000
R13: ffffc9000305f8d8 R14: 0000000000000000 R15: 0000000000000001
FS: 00007fa1a4652700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7e4803c008 CR3: 0000000027153000 CR4: 0000000000350ee0
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 00 00 add %al,(%rax)
4: 41 55 push %r13
6: 41 54 push %r12
8: 41 89 f4 mov %esi,%r12d
b: 55 push %rbp
c: 48 89 fd mov %rdi,%rbp
f: 53 push %rbx
10: e8 6f 61 96 ff callq 0xff966184
15: 48 8d 7d 20 lea 0x20(%rbp),%rdi
19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
20: fc ff df
23: 48 89 fa mov %rdi,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction
2e: 0f 85 2d 04 00 00 jne 0x461
34: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
3b: fc ff df
3e: 4c rex.WR
3f: 8b .byte 0x8b
next prev parent reply other threads:[~2021-09-01 2:00 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-31 22:05 [syzbot] general protection fault in __io_file_supports_nowait syzbot
2021-09-01 2:00 ` syzbot [this message]
2021-09-01 2:08 ` Jens Axboe
2021-09-01 3:34 ` syzbot
2021-09-01 6:41 ` syzbot
2021-10-06 17:54 ` syzbot
2021-10-06 17:55 ` Jens Axboe
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