From 09c8b9718a7af674036643fa2e0dbb2f09aba75e Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 9 May 2018 09:50:22 -0700 Subject: tipc: fix one byte leak in tipc_sk_set_orig_addr() 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 Reported-by: syzbot Cc: Jon Maloy Cc: Ying Xue Acked-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/socket.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'net/tipc') diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 252a52ae0893..6be21575503a 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -1516,10 +1516,10 @@ static void tipc_sk_set_orig_addr(struct msghdr *m, struct sk_buff *skb) 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)) @@ -1528,6 +1528,7 @@ static void tipc_sk_set_orig_addr(struct msghdr *m, struct sk_buff *skb) /* 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; -- cgit v1.2.3