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. -- Jens Axboe
