KMSAN: uninit-value in gre_parse_header
From: syzbot
Date: Sun Jun 23 2019 - 06:37:13 EST
Hello,
syzbot found the following crash on:
HEAD commit: 088c01ea kmsan: fix comment, NFC
git tree: kmsan
console output: https://syzkaller.appspot.com/x/log.txt?x=15efc163200000
kernel config: https://syzkaller.appspot.com/x/.config?x=68044283f8b8640d
dashboard link: https://syzkaller.appspot.com/bug?extid=f583ce3d4ddf9836b27a
compiler: clang version 8.0.0 (trunk 350509)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10775ecd200000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1364b30f200000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+f583ce3d4ddf9836b27a@xxxxxxxxxxxxxxxxxxxxxxxxx
IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready
8021q: adding VLAN 0 to HW filter on device batadv0
raw_sendmsg: syz-executor949 forgot to set AF_INET. Fix it!
==================================================================
BUG: KMSAN: uninit-value in __arch_swab32
arch/x86/include/uapi/asm/swab.h:10 [inline]
BUG: KMSAN: uninit-value in __fswab32 include/uapi/linux/swab.h:59 [inline]
BUG: KMSAN: uninit-value in gre_parse_header+0x1396/0x1690
net/ipv4/gre_demux.c:136
CPU: 1 PID: 10485 Comm: syz-executor949 Not tainted 5.1.0-rc2+ #21
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
<IRQ>
__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:624
__msan_warning+0x7a/0xf0 mm/kmsan/kmsan_instr.c:310
__arch_swab32 arch/x86/include/uapi/asm/swab.h:10 [inline]
__fswab32 include/uapi/linux/swab.h:59 [inline]
gre_parse_header+0x1396/0x1690 net/ipv4/gre_demux.c:136
gre_rcv+0x1c3/0x1800 net/ipv4/ip_gre.c:409
gre_rcv+0x2dd/0x3c0 net/ipv4/gre_demux.c:160
ip_protocol_deliver_rcu+0x584/0xbb0 net/ipv4/ip_input.c:208
ip_local_deliver_finish net/ipv4/ip_input.c:234 [inline]
NF_HOOK include/linux/netfilter.h:289 [inline]
ip_local_deliver+0x624/0x7b0 net/ipv4/ip_input.c:255
dst_input include/net/dst.h:450 [inline]
ip_rcv_finish net/ipv4/ip_input.c:414 [inline]
NF_HOOK include/linux/netfilter.h:289 [inline]
ip_rcv+0x6bd/0x740 net/ipv4/ip_input.c:524
__netif_receive_skb_one_core net/core/dev.c:4973 [inline]
__netif_receive_skb net/core/dev.c:5083 [inline]
process_backlog+0x756/0x10e0 net/core/dev.c:5923
napi_poll net/core/dev.c:6346 [inline]
net_rx_action+0x78b/0x1a60 net/core/dev.c:6412
__do_softirq+0x53f/0x93a kernel/softirq.c:294
do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1039
</IRQ>
do_softirq kernel/softirq.c:339 [inline]
__local_bh_enable_ip+0x1a3/0x1f0 kernel/softirq.c:191
local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
rcu_read_unlock_bh include/linux/rcupdate.h:684 [inline]
ip_finish_output2+0x1721/0x1930 net/ipv4/ip_output.c:231
ip_finish_output+0xd2b/0xfd0 net/ipv4/ip_output.c:317
NF_HOOK_COND include/linux/netfilter.h:278 [inline]
ip_output+0x53f/0x610 net/ipv4/ip_output.c:405
dst_output include/net/dst.h:444 [inline]
ip_local_out net/ipv4/ip_output.c:124 [inline]
ip_send_skb net/ipv4/ip_output.c:1465 [inline]
ip_push_pending_frames+0x243/0x460 net/ipv4/ip_output.c:1485
raw_sendmsg+0x2e31/0x4650 net/ipv4/raw.c:676
inet_sendmsg+0x54a/0x720 net/ipv4/af_inet.c:798
sock_sendmsg_nosec net/socket.c:622 [inline]
sock_sendmsg net/socket.c:632 [inline]
___sys_sendmsg+0xdb3/0x1220 net/socket.c:2137
__sys_sendmmsg+0x580/0xad0 net/socket.c:2232
__do_sys_sendmmsg net/socket.c:2261 [inline]
__se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2258
__x64_sys_sendmmsg+0x56/0x70 net/socket.c:2258
do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x441999
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 bb 10 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffd647de1c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441999
RDX: 0000000000000001 RSI: 00000000200006c0 RDI: 0000000000000004
RBP: 00000000004a9030 R08: 0000000001bbbbbb R09: 0000000001bbbbbb
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402ee0
R13: 0000000000402f70 R14: 0000000000000000 R15: 0000000000000000
Uninit was stored to memory at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:205 [inline]
kmsan_save_stack mm/kmsan/kmsan.c:220 [inline]
kmsan_internal_chain_origin+0x134/0x230 mm/kmsan/kmsan.c:426
kmsan_memcpy_memmove_metadata+0xb5b/0xfe0 mm/kmsan/kmsan.c:304
kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:324
__msan_memcpy+0x58/0x70 mm/kmsan/kmsan_instr.c:139
pskb_expand_head+0x3aa/0x1a30 net/core/skbuff.c:1478
__skb_cow include/linux/skbuff.h:3029 [inline]
skb_cow_head include/linux/skbuff.h:3063 [inline]
ip_tunnel_xmit+0x2c4e/0x3310 net/ipv4/ip_tunnel.c:824
__gre_xmit net/ipv4/ip_gre.c:444 [inline]
erspan_xmit+0x1f5e/0x3640 net/ipv4/ip_gre.c:679
__netdev_start_xmit include/linux/netdevice.h:4411 [inline]
netdev_start_xmit include/linux/netdevice.h:4420 [inline]
xmit_one net/core/dev.c:3278 [inline]
dev_hard_start_xmit+0x604/0xc40 net/core/dev.c:3294
sch_direct_xmit+0x58a/0x880 net/sched/sch_generic.c:327
qdisc_restart net/sched/sch_generic.c:390 [inline]
__qdisc_run+0x1cd7/0x34b0 net/sched/sch_generic.c:398
qdisc_run include/net/pkt_sched.h:121 [inline]
__dev_xmit_skb net/core/dev.c:3473 [inline]
__dev_queue_xmit+0x1e51/0x3ce0 net/core/dev.c:3832
dev_queue_xmit+0x4b/0x60 net/core/dev.c:3897
neigh_resolve_output+0xab7/0xb40 net/core/neighbour.c:1487
neigh_output include/net/neighbour.h:508 [inline]
ip_finish_output2+0x1709/0x1930 net/ipv4/ip_output.c:229
ip_finish_output+0xd2b/0xfd0 net/ipv4/ip_output.c:317
NF_HOOK_COND include/linux/netfilter.h:278 [inline]
ip_output+0x53f/0x610 net/ipv4/ip_output.c:405
dst_output include/net/dst.h:444 [inline]
ip_local_out net/ipv4/ip_output.c:124 [inline]
ip_send_skb net/ipv4/ip_output.c:1465 [inline]
ip_push_pending_frames+0x243/0x460 net/ipv4/ip_output.c:1485
raw_sendmsg+0x2e31/0x4650 net/ipv4/raw.c:676
inet_sendmsg+0x54a/0x720 net/ipv4/af_inet.c:798
sock_sendmsg_nosec net/socket.c:622 [inline]
sock_sendmsg net/socket.c:632 [inline]
___sys_sendmsg+0xdb3/0x1220 net/socket.c:2137
__sys_sendmmsg+0x580/0xad0 net/socket.c:2232
__do_sys_sendmmsg net/socket.c:2261 [inline]
__se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2258
__x64_sys_sendmmsg+0x56/0x70 net/socket.c:2258
do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
entry_SYSCALL_64_after_hwframe+0x63/0xe7
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:173
kmsan_slab_alloc+0xe/0x10 mm/kmsan/kmsan_hooks.c:182
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]
__ip_append_data+0x3671/0x5000 net/ipv4/ip_output.c:1005
ip_append_data+0x324/0x480 net/ipv4/ip_output.c:1220
raw_sendmsg+0x2d2a/0x4650 net/ipv4/raw.c:670
inet_sendmsg+0x54a/0x720 net/ipv4/af_inet.c:798
sock_sendmsg_nosec net/socket.c:622 [inline]
sock_sendmsg net/socket.c:632 [inline]
___sys_sendmsg+0xdb3/0x1220 net/socket.c:2137
__sys_sendmmsg+0x580/0xad0 net/socket.c:2232
__do_sys_sendmmsg net/socket.c:2261 [inline]
__se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2258
__x64_sys_sendmmsg+0x56/0x70 net/socket.c:2258
do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
entry_SYSCALL_64_after_hwframe+0x63/0xe7
==================================================================
---
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