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authorEric Dumazet <edumazet@google.com>2019-08-12 04:57:27 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-09-16 08:20:45 +0200
commit89ea639a2ce5023ccfefc9a85dfd436523efe78f (patch)
tree2b8e278a59a5f81000799d0095d6b83e2de7d27c
parente93482df922b2811bea65c8bbcbd1725c298ec5a (diff)
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batman-adv: fix uninit-value in batadv_netlink_get_ifindex()
commit 3ee1bb7aae97324ec9078da1f00cb2176919563f upstream. batadv_netlink_get_ifindex() needs to make sure user passed a correct u32 attribute. syzbot reported : BUG: KMSAN: uninit-value in batadv_netlink_dump_hardif+0x70d/0x880 net/batman-adv/netlink.c:968 CPU: 1 PID: 11705 Comm: syz-executor888 Not tainted 5.1.0+ #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+0x191/0x1f0 lib/dump_stack.c:113 kmsan_report+0x130/0x2a0 mm/kmsan/kmsan.c:622 __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:310 batadv_netlink_dump_hardif+0x70d/0x880 net/batman-adv/netlink.c:968 genl_lock_dumpit+0xc6/0x130 net/netlink/genetlink.c:482 netlink_dump+0xa84/0x1ab0 net/netlink/af_netlink.c:2253 __netlink_dump_start+0xa3a/0xb30 net/netlink/af_netlink.c:2361 genl_family_rcv_msg net/netlink/genetlink.c:550 [inline] genl_rcv_msg+0xfc1/0x1a40 net/netlink/genetlink.c:627 netlink_rcv_skb+0x431/0x620 net/netlink/af_netlink.c:2486 genl_rcv+0x63/0x80 net/netlink/genetlink.c:638 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline] netlink_unicast+0xf3e/0x1020 net/netlink/af_netlink.c:1337 netlink_sendmsg+0x127e/0x12f0 net/netlink/af_netlink.c:1926 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg net/socket.c:661 [inline] ___sys_sendmsg+0xcc6/0x1200 net/socket.c:2260 __sys_sendmsg net/socket.c:2298 [inline] __do_sys_sendmsg net/socket.c:2307 [inline] __se_sys_sendmsg+0x305/0x460 net/socket.c:2305 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2305 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 RIP: 0033:0x440209 Fixes: b60620cf567b ("batman-adv: netlink: hardif query") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/batman-adv/netlink.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/batman-adv/netlink.c b/net/batman-adv/netlink.c
index ab13b4d58733..edb35bcc046d 100644
--- a/net/batman-adv/netlink.c
+++ b/net/batman-adv/netlink.c
@@ -110,7 +110,7 @@ batadv_netlink_get_ifindex(const struct nlmsghdr *nlh, int attrtype)
{
struct nlattr *attr = nlmsg_find_attr(nlh, GENL_HDRLEN, attrtype);
- return attr ? nla_get_u32(attr) : 0;
+ return (attr && nla_len(attr) == sizeof(u32)) ? nla_get_u32(attr) : 0;
}
/**