On 8/11/20 9:23 AM, Jens Axboe wrote: > On 8/11/20 8:59 AM, Jens Axboe wrote: >> On 8/11/20 7:57 AM, syzbot wrote: >>> Hello, >>> >>> syzbot found the following issue on: >>> >>> HEAD commit: d6efb3ac Merge tag 'tty-5.9-rc1' of git://git.kernel.org/p.. >>> git tree: upstream >>> console output: https://syzkaller.appspot.com/x/log.txt?x=13cb0762900000 >>> kernel config: https://syzkaller.appspot.com/x/.config?x=42163327839348a9 >>> dashboard link: https://syzkaller.appspot.com/bug?extid=a730016dc0bdce4f6ff5 >>> compiler: gcc (GCC) 10.1.0-syz 20200507 >>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16e877dc900000 >>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1608291a900000 >>> >>> IMPORTANT: if you fix the issue, please add the following tag to the commit: >>> Reported-by: syzbot+a730016dc0bdce4f6ff5@xxxxxxxxxxxxxxxxxxxxxxxxx >>> >>> executing program >>> executing program >>> executing program >>> executing program >>> executing program >>> BUG: memory leak >>> unreferenced object 0xffff888124949100 (size 256): >>> comm "syz-executor808", pid 6480, jiffies 4294949911 (age 33.960s) >>> hex dump (first 32 bytes): >>> 00 78 74 2a 81 88 ff ff 00 00 00 00 00 00 00 00 .xt*............ >>> 90 b0 51 81 ff ff ff ff 00 00 00 00 00 00 00 00 ..Q............. >>> backtrace: >>> [<0000000084e46f34>] io_alloc_req fs/io_uring.c:1503 [inline] >>> [<0000000084e46f34>] io_submit_sqes+0x5dc/0xc00 fs/io_uring.c:6306 >>> [<000000006d4e19eb>] __do_sys_io_uring_enter+0x582/0x830 fs/io_uring.c:8036 >>> [<00000000a4116b07>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 >>> [<0000000067b2aefc>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 >>> >>> BUG: memory leak >>> unreferenced object 0xffff88811751d200 (size 96): >>> comm "syz-executor808", pid 6480, jiffies 4294949911 (age 33.960s) >>> hex dump (first 32 bytes): >>> 00 78 74 2a 81 88 ff ff 00 00 00 00 00 00 00 00 .xt*............ >>> 0e 01 00 00 00 00 75 22 00 00 00 00 00 0f 1f 04 ......u"........ >>> backtrace: >>> [<00000000073ea2ba>] kmalloc include/linux/slab.h:555 [inline] >>> [<00000000073ea2ba>] io_arm_poll_handler fs/io_uring.c:4773 [inline] >>> [<00000000073ea2ba>] __io_queue_sqe+0x445/0x6b0 fs/io_uring.c:5988 >>> [<000000001551bde0>] io_queue_sqe+0x309/0x550 fs/io_uring.c:6060 >>> [<000000002dfb908f>] io_submit_sqe fs/io_uring.c:6130 [inline] >>> [<000000002dfb908f>] io_submit_sqes+0x8b8/0xc00 fs/io_uring.c:6327 >>> [<000000006d4e19eb>] __do_sys_io_uring_enter+0x582/0x830 fs/io_uring.c:8036 >>> [<00000000a4116b07>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 >>> [<0000000067b2aefc>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 >> >> This one looks very odd, and I cannot reproduce it. The socket() calls >> reliably fails for me, and even if I hack it to use 0 for protocol instead >> of 2, I don't see anything interesting happening here. An IORING_OP_WRITEV >> is submitted on the socket, which just fails with ENOTCONN. > > Dug a bit deeper and found the missing option, I can now reproduce this! > I'll take a look. This should fix it. diff --git a/fs/io_uring.c b/fs/io_uring.c index 99582cf5106b..8a2afd8c33c9 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -4883,7 +4883,7 @@ static bool io_arm_poll_handler(struct io_kiocb *req) ret = __io_arm_poll_handler(req, &apoll->poll, &ipt, mask, io_async_wake); - if (ret) { + if (ret || ipt.error) { io_poll_remove_double(req, apoll->double_poll); spin_unlock_irq(&ctx->completion_lock); kfree(apoll->double_poll); -- Jens Axboe
