On Tue, Jul 10, 2018 at 10:09 AM, Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote: > On Tue, Jul 10, 2018 at 10:08 AM, syzbot > <syzbot+3a0570f93c0d6ca388f5@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: >> Hello, >> >> syzbot found the following crash on: >> >> HEAD commit: d00d6d9a339d Add linux-next specific files for 20180709 >> git tree: linux-next >> console output: https://syzkaller.appspot.com/x/log.txt?x=17fdd90c400000 >> kernel config: https://syzkaller.appspot.com/x/.config?x=94fe2b586beccacd >> dashboard link: https://syzkaller.appspot.com/bug?extid=3a0570f93c0d6ca388f5 >> compiler: gcc (GCC) 8.0.1 20180413 (experimental) >> >> Unfortunately, I don't have any reproducer for this crash yet. >> >> IMPORTANT: if you fix the bug, please add the following tag to the commit: >> Reported-by: syzbot+3a0570f93c0d6ca388f5@xxxxxxxxxxxxxxxxxxxxxxxxx > > > Look similar to the other hangs in 9p, this time caused by the > following program: > > 21:30:55 executing program 0: > pipe2$9p(&(0x7f0000000100)={<r0=>0xffffffffffffffff, > <r1=>0xffffffffffffffff}, 0x0) > write$P9_RUNLINKAT(r1, &(0x7f0000000040)={0xffffffffffffffca, 0x4d}, 0x7) > mkdir(&(0x7f0000000300)='./file0\x00', 0x0) > mount$9p_fd(0x0, &(0x7f00000000c0)='./file0\x00', > &(0x7f0000000340)='9p\x00', 0x0, &(0x7f00000001c0)={'trans=fd,', > {'rfdno', 0x3d, r0}, 0x2c, {'wfdno', 0x3d, r1}, 0x2c}) > write$P9_RREADDIR(r1, &(0x7f0000000480)={0x2a, 0x29, 0x1, {0x0, [{{}, > 0x0, 0x0, 0x7, './file0'}]}}, 0x2a) > write$P9_RGETATTR(r1, &(0x7f0000000200)={0xa0, 0x19, 0x1}, 0xa0) > write$P9_RWALK(r1, &(0x7f0000000500)=ANY=[@ANYBLOB="090100006f01000000"], 0x9) > mount$9p_fd(0x0, &(0x7f0000000080)='./file0\x00', > &(0x7f0000000900)='9p\x00', 0x0, &(0x7f0000000840)={'trans=fd,', > {'rfdno', 0x3d, r0}, 0x2c, {'wfdno', 0x3d, r1}, 0x2c, > {[{@access_uid={'access', 0x3d}, 0x2c}]}}) > r2 = socket$inet6(0xa, 0x1000000000002, 0x0) > ioctl(r2, 0x8912, &(0x7f0000000280)="025cc83d6d345f8f762070") > utimes(&(0x7f0000000180)='./file0\x00', &(0x7f0000000380)) #syz dup: INFO: task hung in flush_work >> 9pnet_virtio: no channels available for device (null) >> Unknown ioctl 44801 >> 9pnet_virtio: no channels available for device (null) >> 9pnet: Insufficient options for proto=fd >> 9pnet: Insufficient options for proto=fd >> INFO: task syz-executor0:12044 blocked for more than 140 seconds. >> Not tainted 4.18.0-rc3-next-20180709+ #2 >> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. >> syz-executor0 D25408 12044 4539 0x00000004 >> Call Trace: >> context_switch kernel/sched/core.c:2853 [inline] >> __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 >> schedule+0xfb/0x450 kernel/sched/core.c:3545 >> __rwsem_down_write_failed_common+0x95d/0x1630 >> kernel/locking/rwsem-xadd.c:566 >> rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595 >> call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 >> __down_write arch/x86/include/asm/rwsem.h:142 [inline] >> down_write+0xaa/0x130 kernel/locking/rwsem.c:72 >> inode_lock include/linux/fs.h:748 [inline] >> utimes_common.isra.1+0x45c/0x8e0 fs/utimes.c:90 >> do_utimes+0x1f7/0x380 fs/utimes.c:156 >> do_futimesat+0x249/0x350 fs/utimes.c:212 >> __do_sys_utimes fs/utimes.c:225 [inline] >> __se_sys_utimes fs/utimes.c:222 [inline] >> __x64_sys_utimes+0x59/0x80 fs/utimes.c:222 >> do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 >> entry_SYSCALL_64_after_hwframe+0x49/0xbe >> RIP: 0033:0x455e29 >> Code: cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 0f 86 ab 04 00 00 48 83 ec >> 58 48 89 6c 24 50 48 8d 6c 24 50 48 8b 44 24 60 c6 00 00 <48> 8b 4c 24 68 48 >> 89 ca 48 89 50 08 48 8b 59 20 48 01 da 31 db 31 >> RSP: 002b:00007fac7c8b4c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000eb >> RAX: ffffffffffffffda RBX: 00007fac7c8b56d4 RCX: 0000000000455e29 >> RDX: 0000000000000000 RSI: 0000000020000380 RDI: 0000000020000180 >> RBP: 000000000072bff0 R08: 0000000000000000 R09: 0000000000000000 >> R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff >> R13: 00000000004c2af0 R14: 00000000004d4600 R15: 0000000000000002 >> INFO: lockdep is turned off. >> NMI backtrace for cpu 1 >> CPU: 1 PID: 898 Comm: khungtaskd Not tainted 4.18.0-rc3-next-20180709+ #2 >> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS >> Google 01/01/2011 >> Call Trace: >> __dump_stack lib/dump_stack.c:77 [inline] >> dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 >> nmi_cpu_backtrace.cold.5+0x19/0xce lib/nmi_backtrace.c:103 >> nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62 >> arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 >> trigger_all_cpu_backtrace include/linux/nmi.h:143 [inline] >> check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] >> watchdog+0xb39/0x10b0 kernel/hung_task.c:265 >> kthread+0x345/0x410 kernel/kthread.c:246 >> ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 >> Sending NMI from CPU 1 to CPUs 0: >> NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 >> arch/x86/include/asm/irqflags.h:54 >> >> >> --- >> This bug 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 bug report. See: >> https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with >> syzbot. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "syzkaller-bugs" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/syzkaller-bugs/0000000000000bafc80570a0a1db%40google.com. >> For more options, visit https://groups.google.com/d/optout.
