On Thu, Dec 28, 2017 at 10:30:46AM +0100, Dmitry Vyukov wrote: > On Thu, Dec 28, 2017 at 10:20 AM, syzbot > <syzbot+aa0386edb3e128ffa315@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > > > syzkaller hit the following crash on > > 82bcf1def3b5f1251177ad47c44f7e17af039b4b > > git://git.cmpxchg.org/linux-mmots.git/master > > compiler: gcc (GCC) 7.1.1 20170620 > > .config is attached > > Raw console output is attached. > > C reproducer is attached > > syzkaller reproducer is attached. See https://goo.gl/kgGztJ > > for information about syzkaller reproducers > > > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > Reported-by: syzbot+aa0386edb3e128ffa315@xxxxxxxxxxxxxxxxxxxxxxxxx > > It will help syzbot understand when the bug is fixed. See footer for > > details. > > If you forward the report, please keep this part and the footer. > > > > audit: type=1400 audit(1513711793.237:7): avc: denied { map } for > > pid=3151 comm="syzkaller173649" path="/root/syzkaller173649879" dev="sda1" > > ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 > > tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 > > WARNING: CPU: 1 PID: 3151 at kernel/sched/wait.c:79 > > __wake_up_common+0x433/0x770 kernel/sched/wait.c:79 > > Kernel panic - not syncing: panic_on_warn set ... > > > > CPU: 1 PID: 3151 Comm: syzkaller173649 Not tainted 4.15.0-rc2-mm1+ #39 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > > Google 01/01/2011 > > Call Trace: > > __dump_stack lib/dump_stack.c:17 [inline] > > dump_stack+0x194/0x257 lib/dump_stack.c:53 > > panic+0x1e4/0x41c kernel/panic.c:183 > > __warn+0x1dc/0x200 kernel/panic.c:547 > > report_bug+0x211/0x2d0 lib/bug.c:184 > > fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:177 > > fixup_bug arch/x86/kernel/traps.c:246 [inline] > > do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:295 > > do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314 > > invalid_op+0x22/0x40 arch/x86/entry/entry_64.S:1079 > > RIP: 0010:__wake_up_common+0x433/0x770 kernel/sched/wait.c:79 > > RSP: 0018:ffff8801c4897648 EFLAGS: 00010246 > > RAX: 0000000000000000 RBX: ffff8801d8cbfe50 RCX: 0000000000000004 > > RDX: 1ffffffff0c59731 RSI: ffff8801d8cbfe68 RDI: 0000000000000282 > > RBP: ffff8801c4897748 R08: ffff8801c4897858 R09: 0000000000000000 > > R10: 000000000000000b R11: ffffed0038912e48 R12: 0000000000000000 > > R13: ffff8801d8cbfe00 R14: 0000000000000001 R15: ffff8801c4897858 > > __wake_up_locked_key+0x16/0x20 kernel/sched/wait.c:166 > > userfaultfd_release+0x4da/0x750 fs/userfaultfd.c:885 > > __fput+0x333/0x7f0 fs/file_table.c:210 > > ____fput+0x15/0x20 fs/file_table.c:244 > > task_work_run+0x199/0x270 kernel/task_work.c:113 > > exit_task_work include/linux/task_work.h:22 [inline] > > do_exit+0x9bb/0x1ae0 kernel/exit.c:869 > > do_group_exit+0x149/0x400 kernel/exit.c:972 > > SYSC_exit_group kernel/exit.c:983 [inline] > > SyS_exit_group+0x1d/0x20 kernel/exit.c:981 > > entry_SYSCALL_64_fastpath+0x1f/0x96 > > RIP: 0033:0x43e848 > > RSP: 002b:00007ffe33766e08 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 > > RAX: ffffffffffffffda RBX: 00000000006ca800 RCX: 000000000043e848 > > RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 > > RBP: 00000000000014b1 R08: 00000000000000e7 R09: ffffffffffffffd0 > > R10: 0000000000000006 R11: 0000000000000246 R12: 00000000006ca858 > > R13: 00000000006ca858 R14: 0000000000000000 R15: 0000000000002710 > > Dumping ftrace buffer: > > (ftrace buffer empty) > > Kernel Offset: disabled > > Rebooting in 86400 seconds.. > > > This was triggered by just creating a userfaultfd, and happened only > in mmots but stopped happening few days ago. I don't see any recent > commits touching useffaultfd.c in mm tree (other than > "mm/userfaultfd.c: remove duplicate include"). Was a bogus commit > dropped from mm tree? Let's close this bug for now and see if it > happens again: Seems to me it's the same problem as one reported by 01day bot [1]. There was Christoph's patch "sched/wait: assert the wait_queue_head lock is held in __wake_up_common" that Andrew dropped from his tree. This patch revealed, hmm, special wait queue locking in the userfault. [1] https://lkml.org/lkml/2017/12/13/942 > #syz invalid > > > > --- > > This bug is generated by a dumb bot. It may contain errors. > > See https://goo.gl/tpsmEJ for details. > > Direct all questions to syzkaller@xxxxxxxxxxxxxxxx. > > > > syzbot will keep track of this bug report. > > If you forgot to add the Reported-by tag, once the fix for this bug is > > merged > > into any tree, please reply to this email with: > > #syz fix: exact-commit-title > > If you want to test a patch for this bug, please reply with: > > #syz test: git://repo/address.git branch > > and provide the patch inline or as an attachment. > > To mark this as a duplicate of another syzbot report, please reply with: > > #syz dup: exact-subject-of-another-report > > If it's a one-off invalid bug report, please reply with: > > #syz invalid > > Note: if the crash happens again, it will cause creation of a new bug > > report. > > Note: all commands must start from beginning of the line in the email body. > > > > -- > > 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/001a113f542a43cb1f05616305fb%40google.com. > > For more options, visit https://groups.google.com/d/optout. > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@xxxxxxxxx. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> > -- Sincerely yours, Mike. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
