syzbot


KMSAN: uninit-value in rtnl_stats_dump

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: 1940d, last: 1910d

Sample crash report:
IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready
8021q: adding VLAN 0 to HW filter on device batadv0
8021q: adding VLAN 0 to HW filter on device batadv0
8021q: adding VLAN 0 to HW filter on device batadv0
==================================================================
BUG: KMSAN: uninit-value in rtnl_stats_dump+0xe05/0x1240 net/core/rtnetlink.c:5052
CPU: 1 PID: 10633 Comm: syz-executor.5 Not tainted 5.1.0-rc4+ #1
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_dump+0xe05/0x1240 net/core/rtnetlink.c:5052
 netlink_dump+0xa84/0x1ab0 net/netlink/af_netlink.c:2252
 __netlink_dump_start+0xa3b/0xb30 net/netlink/af_netlink.c:2360
 netlink_dump_start include/linux/netlink.h:226 [inline]
 rtnetlink_rcv_msg+0x1423/0x1550 net/core/rtnetlink.c:5155
 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:651 [inline]
 sock_sendmsg net/socket.c:661 [inline]
 ___sys_sendmsg+0xdb3/0x1220 net/socket.c:2260
 __sys_sendmmsg+0x580/0xad0 net/socket.c:2355
 __do_sys_sendmmsg net/socket.c:2384 [inline]
 __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2381
 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2381
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x458c29
Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fba678b5c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000458c29
RDX: 0492492492492805 RSI: 0000000020000140 RDI: 0000000000000003
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fba678b66d4
R13: 00000000004c5c4b R14: 00000000004da078 R15: 00000000ffffffff

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:442 [inline]
 slab_alloc_node mm/slub.c:2771 [inline]
 __kmalloc_node_track_caller+0xead/0x1000 mm/slub.c:4399
 __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:651 [inline]
 sock_sendmsg net/socket.c:661 [inline]
 ___sys_sendmsg+0xdb3/0x1220 net/socket.c:2260
 __sys_sendmmsg+0x580/0xad0 net/socket.c:2355
 __do_sys_sendmmsg net/socket.c:2384 [inline]
 __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2381
 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2381
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
==================================================================

Crashes (14):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/04/12 16:59 https://github.com/google/kmsan.git master 199a02db1f61 8916f5e1 .config console log report syz ci-upstream-kmsan-gce
2019/04/07 17:58 https://github.com/google/kmsan.git master 46200eb9666d c34fde03 .config console log report syz ci-upstream-kmsan-gce
2019/04/02 09:19 https://github.com/google/kmsan.git master 088c01ea0855 a9ca43d4 .config console log report syz ci-upstream-kmsan-gce
2019/04/27 06:54 https://github.com/google/kmsan.git master 199a02db1f61 b617407b .config console log report ci-upstream-kmsan-gce
2019/04/23 01:43 https://github.com/google/kmsan.git master 199a02db1f61 53199d6e .config console log report ci-upstream-kmsan-gce
2019/04/12 09:32 https://github.com/google/kmsan.git master 199a02db1f61 8916f5e1 .config console log report ci-upstream-kmsan-gce
2019/04/07 13:07 https://github.com/google/kmsan.git master 46200eb9666d c34fde03 .config console log report ci-upstream-kmsan-gce
2019/04/05 04:07 https://github.com/google/kmsan.git master 46200eb9666d e5d1b3ac .config console log report ci-upstream-kmsan-gce
2019/04/02 03:29 https://github.com/google/kmsan.git master 088c01ea0855 a9ca43d4 .config console log report ci-upstream-kmsan-gce
2019/04/01 21:21 https://github.com/google/kmsan.git master 088c01ea0855 a9ca43d4 .config console log report ci-upstream-kmsan-gce
2019/03/28 13:37 https://github.com/google/kmsan.git master 35def5ce9fa7 f94f56fe .config console log report ci-upstream-kmsan-gce
2019/03/28 13:34 https://github.com/google/kmsan.git master 35def5ce9fa7 f94f56fe .config console log report ci-upstream-kmsan-gce
2019/03/28 12:54 https://github.com/google/kmsan.git master 35def5ce9fa7 f94f56fe .config console log report ci-upstream-kmsan-gce
2019/03/28 12:33 https://github.com/google/kmsan.git master 35def5ce9fa7 f94f56fe .config console log report ci-upstream-kmsan-gce
* Struck through repros no longer work on HEAD.