Messages in this thread | | | From | Dmitry Vyukov <> | Date | Fri, 2 Nov 2018 16:33:37 +0100 | Subject | Re: WARNING: refcount bug in kobject_put |
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On Fri, Nov 2, 2018 at 4:31 PM, syzbot <syzbot+3ed2626dbfac197ce4d4@syzkaller.appspotmail.com> wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: e468f5c06b5e Merge tag 'compiler-attributes-for-linus-4.20.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=17ad34b9400000 > kernel config: https://syzkaller.appspot.com/x/.config?x=9384ecb1c973baed > dashboard link: https://syzkaller.appspot.com/bug?extid=3ed2626dbfac197ce4d4 > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16f6882b400000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1423f983400000
Looks the same as:
https://syzkaller.appspot.com/bug?id=b52dec65c1aaaec9b3893458b13a3304303de321
#syz dup: WARNING in kernfs_get
> IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+3ed2626dbfac197ce4d4@syzkaller.appspotmail.com > > ------------[ cut here ]------------ > refcount_t: underflow; use-after-free. > WARNING: CPU: 1 PID: 7046 at lib/refcount.c:187 > refcount_sub_and_test_checked+0x2c9/0x310 lib/refcount.c:187 > Kernel panic - not syncing: panic_on_warn set ... > CPU: 1 PID: 7046 Comm: syz-executor895 Not tainted 4.19.0+ #315 > 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+0x244/0x39d lib/dump_stack.c:113 > panic+0x2ad/0x55c kernel/panic.c:188 > __warn.cold.8+0x20/0x45 kernel/panic.c:540 > report_bug+0x254/0x2d0 lib/bug.c:186 > fixup_bug arch/x86/kernel/traps.c:178 [inline] > do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271 > do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:290 > invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:969 > RIP: 0010:refcount_sub_and_test_checked+0x2c9/0x310 lib/refcount.c:187 > Code: 89 de e8 0a 87 ed fd 84 db 74 07 31 db e9 4d ff ff ff e8 2a 86 ed fd > 48 c7 c7 20 9d 60 88 c6 05 85 5e 7f 06 01 e8 c7 e6 b6 fd <0f> 0b 31 db e9 2c > ff ff ff 48 89 cf e8 56 cd 30 fe e9 41 fe ff ff > RSP: 0018:ffff8801bcdd76a8 EFLAGS: 00010286 > RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 > RDX: 0000000000000000 RSI: ffffffff8165d6c5 RDI: 0000000000000005 > RBP: ffff8801bcdd7790 R08: ffff8801bcb98700 R09: ffffed003b5e5020 > R10: ffffed003b5e5020 R11: ffff8801daf28107 R12: ffff8801d72459b8 > R13: 00000000ffffffff R14: ffff8801bcdd7768 R15: ffff8801bcdfa620 > refcount_dec_and_test_checked+0x1a/0x20 lib/refcount.c:212 > kref_put include/linux/kref.h:69 [inline] > kobject_put+0x6c/0xe0 lib/kobject.c:708 > kset_put include/linux/kobject.h:218 [inline] > kobj_kset_leave+0x25b/0x3f0 lib/kobject.c:201 > kobject_del.part.4+0x79/0xf0 lib/kobject.c:596 > kobject_del+0x1f/0x30 lib/kobject.c:588 > cleanup_glue_dir.part.19+0x1c2/0x210 drivers/base/core.c:1651 > cleanup_glue_dir drivers/base/core.c:681 [inline] > device_del+0x813/0xb70 drivers/base/core.c:2094 > hci_unregister_dev+0x3a2/0x990 net/bluetooth/hci_core.c:3355 > vhci_release+0x76/0xf0 drivers/bluetooth/hci_vhci.c:354 > __fput+0x385/0xa30 fs/file_table.c:278 > ____fput+0x15/0x20 fs/file_table.c:309 > task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 > tracehook_notify_resume include/linux/tracehook.h:188 [inline] > exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 > prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] > syscall_return_slowpath arch/x86/entry/common.c:268 [inline] > do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x400dd0 > Code: 01 f0 ff ff 0f 83 b0 0a 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f > 44 00 00 83 3d fd 18 2d 00 00 75 14 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff ff > 0f 83 84 0a 00 00 c3 48 83 ec 08 e8 3a 01 00 00 > RSP: 002b:00007ffc5caf19d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 > RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000400dd0 > RDX: 0000000000000002 RSI: 00000000200000c0 RDI: 0000000000000003 > RBP: 0000000000000000 R08: 00000000004002c8 R09: 00000000004002c8 > R10: 0000000000b0c880 R11: 0000000000000246 R12: 000000000000b95f > R13: 0000000000401d70 R14: 0000000000000000 R15: 0000000000000000 > Kernel Offset: disabled > Rebooting in 86400 seconds.. > > > --- > 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@googlegroups.com. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with > syzbot. > syzbot can test patches for this bug, for details see: > https://goo.gl/tpsmEJ#testing-patches > > -- > 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@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/syzkaller-bugs/0000000000001c5bd90579b039b8%40google.com. > For more options, visit https://groups.google.com/d/optout.
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