On Mon, Jul 9, 2018 at 3:25 PM, syzbot <syzbot+6cd4d2845f652967921c@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=1414611c400000 > kernel config: https://syzkaller.appspot.com/x/.config?x=94fe2b586beccacd > dashboard link: https://syzkaller.appspot.com/bug?extid=6cd4d2845f652967921c > 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+6cd4d2845f652967921c@xxxxxxxxxxxxxxxxxxxxxxxxx >From the log it looks like the following program caused the hang. +9p maintainers 03:43:44 executing program 3: pipe2$9p(&(0x7f0000000100)={<r0=>0xffffffffffffffff, <r1=>0xffffffffffffffff}, 0x0) write$P9_RUNLINKAT(r1, &(0x7f0000000040)={0xffffffffffffffca, 0x4d}, 0x7) mkdir(&(0x7f0000000300)='./file0\x00', 0x100) 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_RSTATFS(r1, &(0x7f0000000640)={0x43, 0x9, 0x1}, 0x43) write$P9_RREADDIR(r1, &(0x7f00000004c0)={0x3ea, 0x29, 0x1, {0x0, [{{0x46, 0x2, 0x8}, 0x1000, 0x7, 0x7, './file0'}, {{0x40, 0x0, 0x2}, 0x9, 0x7ff, 0x7, './file0'}, {{0x10, 0x3, 0x5}, 0x9, 0x2, 0x7, './file0'}, {{0x40, 0x1, 0x4}, 0x400, 0x2, 0x7, './file0'}]}}, 0x87) write$P9_RREMOVE(r1, &(0x7f0000000180)={0x7, 0x7b, 0x1}, 0x7) mount$9p_fd(0x0, &(0x7f0000000000)='./file0\x00', &(0x7f0000000900)='9p\x00', 0x0, &(0x7f0000000840)={'trans=fd,', {'rfdno', 0x3d, r0}, 0x2c, {'wfdno', 0x3d, r1}, 0x2c, {[{@access_uid={'access', 0x3d}, 0x2c}]}}) setxattr(&(0x7f0000000140)='./file0\x00', &(0x7f0000000380)=@known='system.posix_acl_default\x00', &(0x7f0000000400)=':\x00', 0x2, 0x0) > FAT-fs (loop6): Unrecognized mount option "uid=" or missing value > INFO: task syz-executor3:28571 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-executor3 D25408 28571 4477 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] > vfs_setxattr+0x96/0x100 fs/xattr.c:218 > setxattr+0x2ea/0x450 fs/xattr.c:450 > path_setxattr+0x1e3/0x230 fs/xattr.c:469 > __do_sys_setxattr fs/xattr.c:484 [inline] > __se_sys_setxattr fs/xattr.c:480 [inline] > __x64_sys_setxattr+0xc4/0x150 fs/xattr.c:480 > do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x455e29 > Code: Bad RIP value. > RSP: 002b:00007f1c60d88c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc > RAX: ffffffffffffffda RBX: 00007f1c60d896d4 RCX: 0000000000455e29 > RDX: 0000000020000400 RSI: 0000000020000380 RDI: 0000000020000140 > RBP: 000000000072bff0 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000002 R11: 0000000000000246 R12: 00000000ffffffff > R13: 00000000004bbff8 R14: 00000000004d3370 R15: 0000000000000002 > INFO: lockdep is turned off. > NMI backtrace for cpu 1 > CPU: 1 PID: 897 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 > CPU: 0 PID: 2419 Comm: udevd Not tainted 4.18.0-rc3-next-20180709+ #2 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > RIP: 0033:0x4043d1 > Code: d5 b0 00 00 bf a0 54 62 00 e8 9b fb 00 00 bf b0 54 62 00 e8 91 fb 00 > 00 44 89 7c 24 64 4c 89 6c 24 50 49 89 df 44 89 74 24 58 <80> 3d b0 11 22 00 > 00 0f 84 88 07 00 00 83 7c 24 58 00 78 1e 8b 54 > RSP: 002b:00007ffee90bf370 EFLAGS: 00000246 > RAX: 0000000000000001 RBX: 0000000000000000 RCX: 00007ffee90bf46c > RDX: 0000000000000004 RSI: 0000000000000001 RDI: 00000000006254a0 > RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 > R10: 0000000000000008 R11: 0000000000000004 R12: 0000000000000003 > R13: 0000000000000000 R14: 0000000000891520 R15: 0000000000883250 > FS: 00007f96fedce7a0(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffffffffff600400 CR3: 00000001ca6fa000 CR4: 00000000001406f0 > DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 > > > --- > 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/000000000000df6781057090f03d%40google.com. > For more options, visit https://groups.google.com/d/optout.