All 5 console logs listed on the syzkaller dashboard for this one have io-uring with IORING_OP_POLL_ADD somewhere. Could that be related? On Mon, Jan 16, 2023 at 8:31 AM syzbot <syzbot+1d4c86ac0fed92e3fc78@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following issue on: > > HEAD commit: 0a093b2893c7 Add linux-next specific files for 20230112 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=16a8e102480000 > kernel config: https://syzkaller.appspot.com/x/.config?x=835f3591019836d5 > dashboard link: https://syzkaller.appspot.com/bug?extid=1d4c86ac0fed92e3fc78 > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > > Unfortunately, I don't have any reproducer for this issue yet. > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/8111a570d6cb/disk-0a093b28.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/ecc135b7fc9a/vmlinux-0a093b28.xz > kernel image: https://storage.googleapis.com/syzbot-assets/ca8d73b446ea/bzImage-0a093b28.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+1d4c86ac0fed92e3fc78@xxxxxxxxxxxxxxxxxxxxxxxxx > > ------------[ cut here ]------------ > refcount_t: addition on 0; use-after-free. > WARNING: CPU: 0 PID: 5316 at lib/refcount.c:25 refcount_warn_saturate+0x17c/0x1f0 lib/refcount.c:25 > Modules linked in: > CPU: 0 PID: 5316 Comm: syz-executor.4 Not tainted 6.2.0-rc3-next-20230112-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 > RIP: 0010:refcount_warn_saturate+0x17c/0x1f0 lib/refcount.c:25 > Code: 0a 31 ff 89 de e8 d4 13 78 fd 84 db 0f 85 2e ff ff ff e8 57 17 78 fd 48 c7 c7 60 87 a6 8a c6 05 e0 ce 54 0a 01 e8 98 a7 b2 05 <0f> 0b e9 0f ff ff ff e8 38 17 78 fd 0f b6 1d ca ce 54 0a 31 ff 89 > RSP: 0018:ffffc90005967d80 EFLAGS: 00010286 > RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 > RDX: ffff8880829f3a80 RSI: ffffffff8166972c RDI: fffff52000b2cfa2 > RBP: ffff888082ae3aa8 R08: 0000000000000005 R09: 0000000000000000 > R10: 0000000000000001 R11: 0000000000000000 R12: ffff88807e520900 > R13: ffff888082ae3fa8 R14: 0000000000000000 R15: ffff888082ae3aa8 > FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000001b32f23000 CR3: 000000007716c000 CR4: 00000000003506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > __refcount_add include/linux/refcount.h:199 [inline] > __refcount_inc include/linux/refcount.h:250 [inline] > refcount_inc include/linux/refcount.h:267 [inline] > get_task_struct include/linux/sched/task.h:110 [inline] > mm_update_next_owner+0x585/0x7b0 kernel/exit.c:504 > exit_mm kernel/exit.c:562 [inline] > do_exit+0x9a4/0x2a90 kernel/exit.c:854 > do_group_exit+0xd4/0x2a0 kernel/exit.c:1012 > __do_sys_exit_group kernel/exit.c:1023 [inline] > __se_sys_exit_group kernel/exit.c:1021 [inline] > __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1021 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x63/0xcd > RIP: 0033:0x7f51f5a8c0c9 > Code: Unable to access opcode bytes at 0x7f51f5a8c09f. > RSP: 002b:00007ffe3c730ad8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 > RAX: ffffffffffffffda RBX: 000000000000001e RCX: 00007f51f5a8c0c9 > RDX: 00007f51f5a3df7b RSI: ffffffffffffffb8 RDI: 0000000000000000 > RBP: 0000000000000000 R08: 000000002ed3101e R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 > R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffe3c730bc0 > </TASK> > > > --- > 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.
