[PATCH 4.16 47/55] tipc: fix one byte leak in tipc_sk_set_orig_addr()

Greg Kroah-Hartman
2018-05-18T08:15:43Z

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit 09c8b9718a7af674036643fa2e0dbb2f09aba75e ]

sysbot/KMSAN reported an uninit-value in recvmsg() that
I tracked down to tipc_sk_set_orig_addr(), missing
srcaddr->member.scope initialization.

This patches moves srcaddr->sock.scope init to follow
fields order and ease future verifications.

BUG: KMSAN: uninit-value in copy_to_user include/linux/uaccess.h:184 [inline]
BUG: KMSAN: uninit-value in move_addr_to_user+0x32e/0x530 net/socket.c:226
CPU: 0 PID: 4549 Comm: syz-executor287 Not tainted 4.17.0-rc3+ #88
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+0x185/0x1d0 lib/dump_stack.c:113
kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
kmsan_internal_check_memory+0x135/0x1e0 mm/kmsan/kmsan.c:1157
kmsan_copy_to_user+0x69/0x160 mm/kmsan/kmsan.c:1199
copy_to_user include/linux/uaccess.h:184 [inline]
move_addr_to_user+0x32e/0x530 net/socket.c:226
___sys_recvmsg+0x4e2/0x810 net/socket.c:2285
__sys_recvmsg net/socket.c:2328 [inline]
__do_sys_recvmsg net/socket.c:2338 [inline]
__se_sys_recvmsg net/socket.c:2335 [inline]
__x64_sys_recvmsg+0x325/0x460 net/socket.c:2335
do_syscall_64+0x154/0x220 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4455e9
RSP: 002b:00007fe3bd36ddb8 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00000000006dac24 RCX: 00000000004455e9
RDX: 0000000000002002 RSI: 0000000020000400 RDI: 0000000000000003
RBP: 00000000006dac20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff98ce4b6f R14: 00007fe3bd36e9c0 R15: 0000000000000003

Local variable description: ----addr@___sys_recvmsg
Variable was created at:
___sys_recvmsg+0xd5/0x810 net/socket.c:2246
__sys_recvmsg net/socket.c:2328 [inline]
__do_sys_recvmsg net/socket.c:2338 [inline]
__se_sys_recvmsg net/socket.c:2335 [inline]
__x64_sys_recvmsg+0x325/0x460 net/socket.c:2335

Byte 19 of 32 is uninitialized

Fixes: 31c82a2d9d51 ("tipc: add second source address to recvmsg()/recvfrom()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/tipc/socket.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -1518,10 +1518,10 @@ static void tipc_sk_set_orig_addr(struct

srcaddr->sock.family = AF_TIPC;
srcaddr->sock.addrtype = TIPC_ADDR_ID;
+ srcaddr->sock.scope = 0;
srcaddr->sock.addr.id.ref = msg_origport(hdr);
srcaddr->sock.addr.id.node = msg_orignode(hdr);
srcaddr->sock.addr.name.domain = 0;
- srcaddr->sock.scope = 0;
m->msg_namelen = sizeof(struct sockaddr_tipc);

if (!msg_in_group(hdr))
@@ -1530,6 +1530,7 @@ static void tipc_sk_set_orig_addr(struct
/* Group message users may also want to know sending member's id */
srcaddr->member.family = AF_TIPC;
srcaddr->member.addrtype = TIPC_ADDR_NAME;
+ srcaddr->member.scope = 0;
srcaddr->member.addr.name.name.type = msg_nametype(hdr);
srcaddr->member.addr.name.name.instance = TIPC_SKB_CB(skb)->orig_member;
srcaddr->member.addr.name.domain = 0;