Hello, syzbot found the following issue on: HEAD commit: 4ac6d90867a4 Merge tag 'docs-5.15' of git://git.lwn.net/li.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=13a275f5300000 kernel config: https://syzkaller.appspot.com/x/.config?x=3c3a5498e99259cf dashboard link: https://syzkaller.appspot.com/bug?extid=726f2ce6dbbf2ad8d133 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=124a3b49300000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=142e610b300000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+726f2ce6dbbf2ad8d133@xxxxxxxxxxxxxxxxxxxxxxxxx BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 26f41067 P4D 26f41067 PUD 17c87067 PMD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 1 PID: 8473 Comm: iou-wrk-8424 Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 0018:ffffc900016af910 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888036b6c000 RBP: ffff888036b6c000 R08: 0000000000000000 R09: ffff8880191787d7 R10: ffffffff81e263e4 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888036b6c058 R14: ffff888036b6c040 R15: 0000000000000000 FS: 0000000002442400(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 000000001d9bc000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: io_rw_done fs/io_uring.c:2905 [inline] kiocb_done+0x1b3/0x980 fs/io_uring.c:2929 io_read+0x3d3/0x1140 fs/io_uring.c:3503 io_issue_sqe+0x209/0x6ba0 fs/io_uring.c:6558 io_wq_submit_work+0x1d4/0x300 fs/io_uring.c:6707 io_worker_handle_work+0xcb1/0x1950 fs/io-wq.c:560 io_wqe_worker+0x2cc/0xbb0 fs/io-wq.c:609 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Modules linked in: CR2: 0000000000000000 ---[ end trace f60cb53b8a968c33 ]--- RIP: 0010:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 0018:ffffc900016af910 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888036b6c000 RBP: ffff888036b6c000 R08: 0000000000000000 R09: ffff8880191787d7 R10: ffffffff81e263e4 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888036b6c058 R14: ffff888036b6c040 R15: 0000000000000000 FS: 0000000002442400(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 000000001d9bc000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
