syzbot


general protection fault in tty_release
Status: fixed on 2020/10/08 10:30
Reported-by: syzbot+3bf98ab1173aa091fe1a@syzkaller.appspotmail.com
Fix commit: c5c6e00f6cc5 fix regression in "epoll: Keep a reference on files added to the check list"
First crash: 637d, last: 628d

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 (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-54 general protection fault in tty_release C 11 626d 637d 0/2 upstream: reported C repro on 2020/08/29 05:22
linux-4.19 general protection fault in tty_release C done 9 631d 637d 1/1 fixed on 2020/10/05 13:12

Sample crash report:
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: 6472 Comm: syz-executor777 Not tainted 4.14.195-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff888097fdc3c0 task.stack: ffff888098780000
RIP: 0010:file_tty drivers/tty/tty_io.c:179 [inline]
RIP: 0010:__tty_fasync drivers/tty/tty_io.c:2109 [inline]
RIP: 0010:tty_release+0xf0/0xe20 drivers/tty/tty_io.c:1655
RSP: 0018:ffff888098787d80 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff888097184960
RBP: ffff888097184500 R08: ffffffff8a0a19e8 R09: 0000000000000001
R10: 0000000000000000 R11: ffff888097fdc3c0 R12: ffff8880a477eb70
R13: ffff88809e18bd3c R14: ffffffff834296d0 R15: ffff8880a694a600
FS:  00007fe2715d1700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe2715afe78 CR3: 00000000a4c25000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __fput+0x25f/0x7a0 fs/file_table.c:210
 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: 0033:0x4468a9
RSP: 002b:00007fe2715d0db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e9
RAX: 0000000000000000 RBX: 00000000006dbc58 RCX: 00000000004468a9
RDX: 0000000000000006 RSI: 0000000000000001 RDI: 0000000000000007
RBP: 00000000006dbc50 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020000380 R11: 0000000000000246 R12: 00000000006dbc5c
R13: 00007fff7b71419f R14: 00007fe2715d19c0 R15: 20c49ba5e353f7cf
Code: df 48 c1 ea 03 80 3c 02 00 0f 85 10 0c 00 00 48 8b 04 24 48 8b 98 90 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 <80> 3c 02 00 0f 85 ab 0b 00 00 48 8b 04 24 48 8b 1b 48 8d 78 20 
RIP: file_tty drivers/tty/tty_io.c:179 [inline] RSP: ffff888098787d80
RIP: __tty_fasync drivers/tty/tty_io.c:2109 [inline] RSP: ffff888098787d80
RIP: tty_release+0xf0/0xe20 drivers/tty/tty_io.c:1655 RSP: ffff888098787d80
---[ end trace 5737d22b212a06be ]---

Crashes (10):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-14 2020/08/29 06:15 linux-4.14.y d7e78d08fa77 d5a3ae1f .config log report syz C
ci2-linux-4-14 2020/09/08 02:08 linux-4.14.y 2f166cdcf8a9 abf9ba4f .config log report syz
ci2-linux-4-14 2020/09/04 21:44 linux-4.14.y 2f166cdcf8a9 abf9ba4f .config log report syz
ci2-linux-4-14 2020/09/04 17:27 linux-4.14.y 2f166cdcf8a9 abf9ba4f .config log report syz
ci2-linux-4-14 2020/09/03 22:50 linux-4.14.y 2f166cdcf8a9 abf9ba4f .config log report syz
ci2-linux-4-14 2020/08/31 06:26 linux-4.14.y d7e78d08fa77 d5a3ae1f .config log report syz
ci2-linux-4-14 2020/08/29 07:28 linux-4.14.y d7e78d08fa77 d5a3ae1f .config log report syz
ci2-linux-4-14 2020/08/29 06:48 linux-4.14.y d7e78d08fa77 d5a3ae1f .config log report syz
ci2-linux-4-14 2020/08/29 05:57 linux-4.14.y d7e78d08fa77 d5a3ae1f .config log report syz
ci2-linux-4-14 2020/08/29 05:22 linux-4.14.y d7e78d08fa77 d5a3ae1f .config log report syz