On 7/16/21 11:57 AM, syzbot wrote: > Hello, > > syzbot has tested the proposed patch but the reproducer is still triggering an issue: > WARNING in io_uring_cancel_generic __arm_poll doesn't remove a second poll entry in case of failed __io_queue_proc(), it's most likely the cause here. #syz test: https://github.com/isilence/linux.git syztest_sqpoll_hang > > ctx ffff8880467ee000 submitted 1, dismantled 0, crefs 0, inflight 1, fallbacks 0, poll1 0, poll2 0, tw 0, hash 0, cs 0, issued 1 > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 18216 at fs/io_uring.c:9142 io_dump fs/io_uring.c:9142 [inline] > WARNING: CPU: 0 PID: 18216 at fs/io_uring.c:9142 io_uring_cancel_generic+0x608/0xea0 fs/io_uring.c:9198 > Modules linked in: > CPU: 0 PID: 18216 Comm: iou-sqp-18211 Not tainted 5.14.0-rc1-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:io_dump fs/io_uring.c:9142 [inline] > RIP: 0010:io_uring_cancel_generic+0x608/0xea0 fs/io_uring.c:9198 > Code: 48 c1 ea 03 80 3c 02 00 0f 85 d5 02 00 00 48 8b 44 24 10 48 8b a8 98 00 00 00 48 39 6c 24 08 0f 85 02 03 00 00 e8 f8 97 92 ff <0f> 0b e9 af fe ff ff e8 ec 97 92 ff 48 8b 74 24 20 b9 08 00 00 00 > RSP: 0018:ffffc9000afefc40 EFLAGS: 00010293 > RAX: 0000000000000000 RBX: ffff88802a09d4c0 RCX: 0000000000000000 > RDX: ffff88802a09d4c0 RSI: ffffffff81e2f0b8 RDI: ffff8880467ee510 > RBP: ffff8880462fb788 R08: 0000000000000081 R09: 0000000000000000 > R10: ffffffff815d066e R11: 0000000000000000 R12: ffff8880462fa458 > R13: ffffc9000afefd40 R14: 0000000000000001 R15: 0000000000000000 > FS: 00007f9295c2d700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f1c3f1a3000 CR3: 0000000018755000 CR4: 0000000000350ee0 > Call Trace: > io_sq_thread+0xaac/0x1250 fs/io_uring.c:6932 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 > Kernel panic - not syncing: panic_on_warn set ... > CPU: 0 PID: 18216 Comm: iou-sqp-18211 Not tainted 5.14.0-rc1-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:88 [inline] > dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105 > panic+0x306/0x73d kernel/panic.c:232 > __warn.cold+0x35/0x44 kernel/panic.c:606 > report_bug+0x1bd/0x210 lib/bug.c:199 > handle_bug+0x3c/0x60 arch/x86/kernel/traps.c:239 > exc_invalid_op+0x14/0x40 arch/x86/kernel/traps.c:259 > asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:566 > RIP: 0010:io_dump fs/io_uring.c:9142 [inline] > RIP: 0010:io_uring_cancel_generic+0x608/0xea0 fs/io_uring.c:9198 > Code: 48 c1 ea 03 80 3c 02 00 0f 85 d5 02 00 00 48 8b 44 24 10 48 8b a8 98 00 00 00 48 39 6c 24 08 0f 85 02 03 00 00 e8 f8 97 92 ff <0f> 0b e9 af fe ff ff e8 ec 97 92 ff 48 8b 74 24 20 b9 08 00 00 00 > RSP: 0018:ffffc9000afefc40 EFLAGS: 00010293 > RAX: 0000000000000000 RBX: ffff88802a09d4c0 RCX: 0000000000000000 > RDX: ffff88802a09d4c0 RSI: ffffffff81e2f0b8 RDI: ffff8880467ee510 > RBP: ffff8880462fb788 R08: 0000000000000081 R09: 0000000000000000 > R10: ffffffff815d066e R11: 0000000000000000 R12: ffff8880462fa458 > R13: ffffc9000afefd40 R14: 0000000000000001 R15: 0000000000000000 > io_sq_thread+0xaac/0x1250 fs/io_uring.c:6932 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 > Kernel Offset: disabled > Rebooting in 86400 seconds.. > > > Tested on: > > commit: 81fee56e io_uring: add syz debug info > git tree: https://github.com/isilence/linux.git syztest_sqpoll_hang > console output: https://syzkaller.appspot.com/x/log.txt?x=12bb485c300000 > kernel config: https://syzkaller.appspot.com/x/.config?x=cfe2c0e42bc9993d > dashboard link: https://syzkaller.appspot.com/bug?extid=ac957324022b7132accf > compiler: > -- Pavel Begunkov
