syzbot


KMSAN: uninit-value in rtnl_stats_get

Status: fixed on 2019/05/27 12:48
Subsystems: net
[Documentation on labels]
Fix commit: 69f23a09daf9 rtnetlink: fix rtnl_valid_stats_req() nlmsg_len check
First crash: 1904d, last: 1891d

Sample crash report:
sshd (10414) used greatest stack depth: 53616 bytes left
==================================================================
BUG: KMSAN: uninit-value in rtnl_stats_get+0x6d9/0x11d0 net/core/rtnetlink.c:4997
CPU: 0 PID: 10428 Comm: syz-executor034 Not tainted 5.1.0-rc2+ #24
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x173/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x131/0x2a0 mm/kmsan/kmsan.c:619
 __msan_warning+0x7a/0xf0 mm/kmsan/kmsan_instr.c:310
 rtnl_stats_get+0x6d9/0x11d0 net/core/rtnetlink.c:4997
 rtnetlink_rcv_msg+0x115b/0x1550 net/core/rtnetlink.c:5192
 netlink_rcv_skb+0x431/0x620 net/netlink/af_netlink.c:2485
 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:5210
 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
 netlink_unicast+0xf3e/0x1020 net/netlink/af_netlink.c:1336
 netlink_sendmsg+0x127f/0x1300 net/netlink/af_netlink.c:1925
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg net/socket.c:632 [inline]
 ___sys_sendmsg+0xdb3/0x1220 net/socket.c:2137
 __sys_sendmsg net/socket.c:2175 [inline]
 __do_sys_sendmsg net/socket.c:2184 [inline]
 __se_sys_sendmsg+0x305/0x460 net/socket.c:2182
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2182
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x4401e9
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffc33acd988 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004401e9
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401a70
R13: 0000000000401b00 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:205 [inline]
 kmsan_internal_poison_shadow+0x92/0x150 mm/kmsan/kmsan.c:159
 kmsan_kmalloc+0xa9/0x130 mm/kmsan/kmsan_hooks.c:174
 kmsan_slab_alloc+0xe/0x10 mm/kmsan/kmsan_hooks.c:183
 slab_post_alloc_hook mm/slab.h:441 [inline]
 slab_alloc_node mm/slub.c:2771 [inline]
 __kmalloc_node_track_caller+0xead/0x1000 mm/slub.c:4396
 __kmalloc_reserve net/core/skbuff.c:140 [inline]
 __alloc_skb+0x309/0xa20 net/core/skbuff.c:208
 alloc_skb include/linux/skbuff.h:1059 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline]
 netlink_sendmsg+0xb82/0x1300 net/netlink/af_netlink.c:1900
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg net/socket.c:632 [inline]
 ___sys_sendmsg+0xdb3/0x1220 net/socket.c:2137
 __sys_sendmsg net/socket.c:2175 [inline]
 __do_sys_sendmsg net/socket.c:2184 [inline]
 __se_sys_sendmsg+0x305/0x460 net/socket.c:2182
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2182
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
==================================================================

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/04/07 05:31 https://github.com/google/kmsan.git master 46200eb9666d c34fde03 .config console log report syz C ci-upstream-kmsan-gce
2019/04/20 09:32 https://github.com/google/kmsan.git master 199a02db1f61 b0e8efcb .config console log report ci-upstream-kmsan-gce
2019/04/12 09:52 https://github.com/google/kmsan.git master 199a02db1f61 8916f5e1 .config console log report ci-upstream-kmsan-gce
2019/04/11 01:18 https://github.com/google/kmsan.git master 199a02db1f61 e955ac50 .config console log report ci-upstream-kmsan-gce
2019/04/06 18:55 https://github.com/google/kmsan.git master 46200eb9666d c34fde03 .config console log report ci-upstream-kmsan-gce
* Struck through repros no longer work on HEAD.