syzbot


KMSAN: uninit-value in packet_set_ring

Status: fixed on 2018/05/08 18:30
Subsystems: net
[Documentation on labels]
Fix commit: 5171b37d9596 net: af_packet: fix race in PACKET_{R|T}X_RING
First crash: 2203d, last: 2186d

Sample crash report:
==================================================================
BUG: KMSAN: uninit-value in packet_set_ring+0x1254/0x3870 net/packet/af_packet.c:4249
CPU: 0 PID: 20195 Comm: syzkaller707632 Not tainted 4.16.0+ #83
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:676
 packet_set_ring+0x1254/0x3870 net/packet/af_packet.c:4249
 packet_setsockopt+0x12c6/0x5a90 net/packet/af_packet.c:3662
 SYSC_setsockopt+0x4b8/0x570 net/socket.c:1849
 SyS_setsockopt+0x76/0xa0 net/socket.c:1828
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x449099
RSP: 002b:00007f42b5307ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 000000000070003c RCX: 0000000000449099
RDX: 0000000000000005 RSI: 0000000000000107 RDI: 0000000000000003
RBP: 0000000000700038 R08: 000000000000001c R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000080eecf R14: 00007f42b53089c0 R15: 0000000000000001

Local variable description: ----req_u@packet_setsockopt
Variable was created at:
 packet_setsockopt+0x13f/0x5a90 net/packet/af_packet.c:3612
 SYSC_setsockopt+0x4b8/0x570 net/socket.c:1849
==================================================================

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/04/15 07:38 https://github.com/google/kmsan.git master 35ff515e4bda 7a67784c .config console log report syz C ci-upstream-kmsan-gce
2018/05/02 02:57 https://github.com/google/kmsan.git master d2d741e5d189 d5b114b4 .config console log report syz ci-upstream-kmsan-gce
2018/05/01 14:05 https://github.com/google/kmsan.git master d2d741e5d189 d5b114b4 .config console log report ci-upstream-kmsan-gce
2018/04/30 15:48 https://github.com/google/kmsan.git master d2d741e5d189 06db3cec .config console log report ci-upstream-kmsan-gce
2018/04/24 07:26 https://github.com/google/kmsan.git master d2d741e5d189 e7e85d36 .config console log report ci-upstream-kmsan-gce
2018/04/15 06:59 https://github.com/google/kmsan.git master 35ff515e4bda 7a67784c .config console log report ci-upstream-kmsan-gce
* Struck through repros no longer work on HEAD.