syzbot


general protection fault in kmem_cache_free

Status: fixed on 2020/10/03 03:40
Reported-by: syzbot+34def952a19f0cae39dd@syzkaller.appspotmail.com
Fix commit: c5c6e00f6cc5 fix regression in "epoll: Keep a reference on files added to the check list"
First crash: 888d, last: 888d

Fix bisection: fixed by (bisect log) :
commit c5c6e00f6cc5d3ed0d6464b14e33f2f5c8505888
Author: Al Viro <viro@zeniv.linux.org.uk>
Date: Wed Sep 2 15:30:48 2020 +0000

  fix regression in "epoll: Keep a reference on files added to the check list"

similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in kmem_cache_free C 1 1676d 1676d 0/24 closed as invalid on 2018/07/07 11:48

Sample crash report:
batman_adv: batadv0: Interface activated: batadv_slave_1
IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 6619 Comm: syz-executor.0 Not tainted 4.14.195-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff888094daa640 task.stack: ffff8880955d8000
RIP: 0010:__read_once_size include/linux/compiler.h:183 [inline]
RIP: 0010:kasan_slab_free+0x34/0x1a0 mm/kasan/kasan.c:512
RSP: 0018:ffff8880955dfb78 EFLAGS: 00010096
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: 0000000000000004 RSI: 0000000000000000 RDI: dffffc0000000000
RBP: ffff8880955dfda8 R08: ffffffff8a083a68 R09: 0000000000000000
R10: 0000000000000000 R11: ffff888094daa640 R12: ffff8880aa50b380
R13: 0000000000000000 R14: ffffffff84e70bd0 R15: ffff888096f94310
FS:  000000000224a940(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0a77fbc740 CR3: 000000008d29d000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __cache_free mm/slab.c:3496 [inline]
 kmem_cache_free+0x7c/0x2b0 mm/slab.c:3758
 security_file_free+0x42/0x80 security/security.c:879
 __fput+0x26c/0x7a0 fs/file_table.c:211
 task_work_run+0x11f/0x190 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x1ad/0x200 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x416f01
RSP: 002b:00007ffcd789a020 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000416f01
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000001190358 R09: 0000000000000000
R10: 00007ffcd789a100 R11: 0000000000000293 R12: 0000000001190360
R13: 0000000000000000 R14: ffffffffffffffff R15: 000000000118cf4c
Code: 00 48 b9 00 00 00 00 00 fc ff df 55 48 89 e5 41 55 49 89 f5 41 54 49 89 fc 48 89 f7 48 c1 ef 03 53 48 01 cf 48 81 ec 18 02 00 00 <0f> b6 07 3c 07 0f 87 20 01 00 00 49 63 44 24 74 48 83 e8 01 48 
RIP: __read_once_size include/linux/compiler.h:183 [inline] RSP: ffff8880955dfb78
RIP: kasan_slab_free+0x34/0x1a0 mm/kasan/kasan.c:512 RSP: ffff8880955dfb78
---[ end trace 318c1ca1c963698f ]---

Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-linux-4-14 2020/09/02 08:52 linux-4.14.y d7e78d08fa77 abf9ba4f .config console log report syz
ci2-linux-4-14 2020/09/01 20:54 linux-4.14.y d7e78d08fa77 abf9ba4f .config console log report syz
ci2-linux-4-14 2020/09/01 19:28 linux-4.14.y d7e78d08fa77 abf9ba4f .config console log report
* Struck through repros no longer work on HEAD.