KMSAN: uninit-value in pppol2tp_connect

Status: fixed on 2018/05/08 18:30
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+a70ac890b23b1bf29f5c@syzkaller.appspotmail.com
Fix commit: eb1c28c05894 l2tp: check sockaddr length in pppol2tp_connect()
First crash: 3027d, last: 3010d
▶ ▼ Discussions (8)
Title Replies (including bot) Last reply
[PATCH 3.16 000/366] 3.16.60-rc1 review 370 (370) 2019/03/29 15:47
[PATCH 4.4 00/50] 4.4.130-stable review 69 (69) 2018/05/12 19:44
[PATCH 4.16 00/81] 4.16.6-stable review 88 (88) 2018/04/28 15:52
[PATCH 4.14 00/80] 4.14.38-stable review 90 (90) 2018/04/28 14:28
[PATCH 4.9 00/74] 4.9.97-stable review 80 (80) 2018/04/28 14:26
[PATCH 3.18 00/24] 3.18.107-stable review 36 (36) 2018/04/28 14:24
[PATCH net] l2tp: check sockaddr length in pppol2tp_connect() 3 (3) 2018/04/24 08:23
KMSAN: uninit-value in pppol2tp_connect 0 (1) 2018/04/23 08:24

Sample crash report:
==================================================================
BUG: KMSAN: uninit-value in pppol2tp_connect+0x258/0x1c50 net/l2tp/l2tp_ppp.c:622
CPU: 1 PID: 4524 Comm: syzkaller735385 Not tainted 4.16.0+ #85
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+0x185/0x1d0 lib/dump_stack.c:53
 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:683
 pppol2tp_connect+0x258/0x1c50 net/l2tp/l2tp_ppp.c:622
 SYSC_connect+0x41a/0x510 net/socket.c:1639
 SyS_connect+0x54/0x80 net/socket.c:1620
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x445559
RSP: 002b:00007f0b96f0ddb8 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00000000006dac24 RCX: 0000000000445559
RDX: 0000000000000000 RSI: 0000000020000200 RDI: 0000000000000003
RBP: 00000000006dac20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffec2b0929f R14: 00007f0b96f0e9c0 R15: 0000000000000001

Local variable description: ----address@SYSC_connect
Variable was created at:
 SYSC_connect+0x6f/0x510 net/socket.c:1622
 SyS_connect+0x54/0x80 net/socket.c:1620
==================================================================

Crashes (13):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/04/21 20:18 https://github.com/google/kmsan.git master a7f95e9c8a95 d23fcf6c .config console log report syz C ci-upstream-kmsan-gce
2018/05/08 09:36 https://github.com/google/kmsan.git master d2d741e5d189 045bbd4a .config console log report ci-upstream-kmsan-gce
2018/05/07 23:53 https://github.com/google/kmsan.git master d2d741e5d189 9e0846e8 .config console log report ci-upstream-kmsan-gce
2018/05/07 20:40 https://github.com/google/kmsan.git master d2d741e5d189 9e0846e8 .config console log report ci-upstream-kmsan-gce
2018/05/07 11:34 https://github.com/google/kmsan.git master d2d741e5d189 a211da1a .config console log report ci-upstream-kmsan-gce
2018/05/06 04:23 https://github.com/google/kmsan.git master d2d741e5d189 78b251cb .config console log report ci-upstream-kmsan-gce
2018/05/03 16:21 https://github.com/google/kmsan.git master d2d741e5d189 9ce14f4b .config console log report ci-upstream-kmsan-gce
2018/05/02 03:18 https://github.com/google/kmsan.git master d2d741e5d189 d5b114b4 .config console log report ci-upstream-kmsan-gce
2018/04/27 15:01 https://github.com/google/kmsan.git master d2d741e5d189 7785e404 .config console log report ci-upstream-kmsan-gce
2018/04/26 02:44 https://github.com/google/kmsan.git master d2d741e5d189 73417389 .config console log report ci-upstream-kmsan-gce
2018/04/25 06:41 https://github.com/google/kmsan.git master d2d741e5d189 37e76fe2 .config console log report ci-upstream-kmsan-gce
2018/04/23 06:06 https://github.com/google/kmsan.git master d2d741e5d189 d23fcf6c .config console log report ci-upstream-kmsan-gce
2018/04/21 19:30 https://github.com/google/kmsan.git master a7f95e9c8a95 d23fcf6c .config console log report ci-upstream-kmsan-gce
* Struck through repros no longer work on HEAD.