Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-25 05:32:00 +00:00
Code Issues Packages Projects Releases Wiki Activity

ipv4: fix uninit-value in ip_route_output_key_hash_rcu()

Browse Source 
syzbot complained that res.type could be used while not initialized.

Using RTN_UNSPEC as initial value seems better than using garbage.

BUG: KMSAN: uninit-value in __mkroute_output net/ipv4/route.c:2200 [inline]
BUG: KMSAN: uninit-value in ip_route_output_key_hash_rcu+0x31f0/0x3940 net/ipv4/route.c:2493
CPU: 1 PID: 12207 Comm: syz-executor0 Not tainted 4.16.0+ #81
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
 __mkroute_output net/ipv4/route.c:2200 [inline]
 ip_route_output_key_hash_rcu+0x31f0/0x3940 net/ipv4/route.c:2493
 ip_route_output_key_hash net/ipv4/route.c:2322 [inline]
 __ip_route_output_key include/net/route.h:126 [inline]
 ip_route_output_flow+0x1eb/0x3c0 net/ipv4/route.c:2577
 raw_sendmsg+0x1861/0x3ed0 net/ipv4/raw.c:653
 inet_sendmsg+0x48d/0x740 net/ipv4/af_inet.c:764
 sock_sendmsg_nosec net/socket.c:630 [inline]
 sock_sendmsg net/socket.c:640 [inline]
 SYSC_sendto+0x6c3/0x7e0 net/socket.c:1747
 SyS_sendto+0x8a/0xb0 net/socket.c:1715
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x455259
RSP: 002b:00007fdc0625dc68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fdc0625e6d4 RCX: 0000000000455259
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000020000080 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000004f7 R14: 00000000006fa7c8 R15: 0000000000000000

Local variable description: ----res.i.i@ip_route_output_flow
Variable was created at:
 ip_route_output_flow+0x75/0x3c0 net/ipv4/route.c:2576
 raw_sendmsg+0x1861/0x3ed0 net/ipv4/raw.c:653

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2018-04-07 13:42:42 -07:00 committed by David S. Miller
parent b855ff8274
commit d0ea2b1250
1 changed files with 6 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
net/ipv4/route.c
View File

@ -2297,13 +2297,14 @@ struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
const struct sk_buff *skb)
{
__u8 tos = RT_FL_TOS(fl4);
struct fib_result res;
struct fib_result res = {
.type = RTN_UNSPEC,
.fi = NULL,
.table = NULL,
.tclassid = 0,
};
struct rtable *rth;
res.tclassid = 0;
res.fi = NULL;
res.table = NULL;
fl4->flowi4_iif = LOOPBACK_IFINDEX;
fl4->flowi4_tos = tos & IPTOS_RT_MASK;
fl4->flowi4_scope = ((tos & RTO_ONLINK) ?