syzbot


BUG: unable to handle page fault for address = ADDR

Status: fixed on 2019/05/27 12:48
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+45474c076a4927533d2e@syzkaller.appspotmail.com
Fix commit: baf76f0c58ae slip: make slhc_free() silently accept an error pointer
First crash: 1886d, last: 1885d
Cause bisection: introduced by (bisect log) :
commit bcdd0ca8cb8730573afebcaae4138f8f4c8eaa20
Author: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Wed Apr 25 11:12:31 2018 +0000

  tty: Use __GFP_NOFAIL for tty_ldisc_get()

Crash: BUG: unable to handle kernel paging request in slhc_free (log)
Repro: C syz .config
  
Discussions (8)
Title Replies (including bot) Last reply
[PATCH 3.16 000/157] 3.16.72-rc1 review 162 (162) 2019/08/11 15:25
[PATCH 4.4 000/266] 4.4.180-stable review 282 (282) 2019/05/17 09:42
[PATCH 3.18 00/86] 3.18.140-stable review 93 (93) 2019/05/16 14:59
[PATCH 5.0 00/89] 5.0.11-stable review 106 (106) 2019/05/03 11:48
[PATCH 4.19 000/100] 4.19.38-stable review 108 (108) 2019/05/02 05:30
[PATCH 4.14 00/53] 4.14.115-stable review 59 (59) 2019/05/01 16:44
[PATCH 4.9 00/41] 4.9.172-stable review 47 (47) 2019/05/01 16:43
BUG: unable to handle page fault for address = ADDR 3 (4) 2019/04/27 01:27

Sample crash report:
 do_syscall_64+0x103/0x670 arch/x86/entry/common.c:298
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x441149
Code: e8 5c ae 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 bb 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fffd8ae1c38 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441149
RDX: 0000000020000140 RSI: 0000000000005423 RDI: 0000000000000003
RBP: 00007fffd8ae1c50 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff
R13: 0000000000000004 R14: 0000000000000000 R15: 0000000000000000
BUG: unable to handle page fault for address = fffffffffffffff4
#PF: supervisor-privileged read access from kernel code
#PF: error_code(0x0000) - not-present page
PGD 8870067 P4D 8870067 PUD 8872067 PMD 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 7949 Comm: syz-executor714 Not tainted 5.1.0-rc6-next-20190424 #30
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:slhc_free+0x31/0xb0 drivers/net/slip/slhc.c:159
Code: 54 49 89 fc e8 c0 b3 15 fd 4d 85 e4 74 77 e8 b6 b3 15 fd 4c 89 e2 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 75 6d <4d> 8b 2c 24 4d 85 ed 74 0d e8 91 b3 15 fd 4c 89 ef e8 09 5b 4e fd
RSP: 0018:ffff8880a3e7f9f0 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: fffffffffffffff4 RCX: 1ffff1101426e1c6
RDX: 1ffffffffffffffe RSI: ffffffff845b7bea RDI: fffffffffffffff4
RBP: ffff8880a3e7fa00 R08: ffff8880a1370540 R09: ffff8880a1370e30
R10: 0000000000000000 R11: 0000000000000000 R12: fffffffffffffff4
R13: ffff88809f531040 R14: 00000000ffffff97 R15: ffff8880a3dff2c0
FS:  0000555556f4d880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffff4 CR3: 000000008b56d000 CR4: 00000000001406e0
Call Trace:
 sl_alloc_bufs drivers/net/slip/slip.c:196 [inline]
 slip_open+0xe16/0x1138 drivers/net/slip/slip.c:821
 tty_ldisc_open.isra.0+0x8b/0xe0 drivers/tty/tty_ldisc.c:469
 tty_set_ldisc+0x2d7/0x690 drivers/tty/tty_ldisc.c:596
 tiocsetd drivers/tty/tty_io.c:2332 [inline]
 tty_ioctl+0x5dc/0x15c0 drivers/tty/tty_io.c:2592
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0xd6e/0x1390 fs/ioctl.c:696
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0x103/0x670 arch/x86/entry/common.c:298
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x441149
Code: e8 5c ae 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 bb 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fffd8ae1c38 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441149
RDX: 0000000020000140 RSI: 0000000000005423 RDI: 0000000000000003
RBP: 00007fffd8ae1c50 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff
R13: 0000000000000004 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
CR2: fffffffffffffff4
---[ end trace c314d2d667c67584 ]---
RIP: 0010:slhc_free+0x31/0xb0 drivers/net/slip/slhc.c:159
Code: 54 49 89 fc e8 c0 b3 15 fd 4d 85 e4 74 77 e8 b6 b3 15 fd 4c 89 e2 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 75 6d <4d> 8b 2c 24 4d 85 ed 74 0d e8 91 b3 15 fd 4c 89 ef e8 09 5b 4e fd
RSP: 0018:ffff8880a3e7f9f0 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: fffffffffffffff4 RCX: 1ffff1101426e1c6
RDX: 1ffffffffffffffe RSI: ffffffff845b7bea RDI: fffffffffffffff4
RBP: ffff8880a3e7fa00 R08: ffff8880a1370540 R09: ffff8880a1370e30
R10: 0000000000000000 R11: 0000000000000000 R12: fffffffffffffff4
R13: ffff88809f531040 R14: 00000000ffffff97 R15: ffff8880a3dff2c0
FS:  0000555556f4d880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffff4 CR3: 000000008b56d000 CR4: 00000000001406e0

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/04/25 09:28 linux-next c392798a85ab 8e3c52b1 .config console log report syz C ci-upstream-linux-next-kasan-gce-root
2019/04/25 09:10 linux-next c392798a85ab 8e3c52b1 .config console log report ci-upstream-linux-next-kasan-gce-root
2019/04/25 03:32 linux-next c392798a85ab 8e3c52b1 .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.