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| author | Xin Long <lucien.xin@gmail.com> | 2019-03-31 16:50:08 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-04-01 01:45:57 +0200 |
| commit | 6f07e5f06c8712acc423485f657799fc8e11e56c (patch) | |
| tree | 5d93cf099573caa4f8b8a9b3aa6103ace0f1ac07 /net | |
| parent | Merge branch 'net-stmmac-fix-handling-of-oversized-frames' (diff) | |
| download | linux-6f07e5f06c8712acc423485f657799fc8e11e56c.tar.xz linux-6f07e5f06c8712acc423485f657799fc8e11e56c.zip | |
tipc: check bearer name with right length in tipc_nl_compat_bearer_enable
Syzbot reported the following crash:
BUG: KMSAN: uninit-value in memchr+0xce/0x110 lib/string.c:961
memchr+0xce/0x110 lib/string.c:961
string_is_valid net/tipc/netlink_compat.c:176 [inline]
tipc_nl_compat_bearer_enable+0x2c4/0x910 net/tipc/netlink_compat.c:401
__tipc_nl_compat_doit net/tipc/netlink_compat.c:321 [inline]
tipc_nl_compat_doit+0x3aa/0xaf0 net/tipc/netlink_compat.c:354
tipc_nl_compat_handle net/tipc/netlink_compat.c:1162 [inline]
tipc_nl_compat_recv+0x1ae7/0x2750 net/tipc/netlink_compat.c:1265
genl_family_rcv_msg net/netlink/genetlink.c:601 [inline]
genl_rcv_msg+0x185f/0x1a60 net/netlink/genetlink.c:626
netlink_rcv_skb+0x431/0x620 net/netlink/af_netlink.c:2477
genl_rcv+0x63/0x80 net/netlink/genetlink.c:637
netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
netlink_unicast+0xf3e/0x1020 net/netlink/af_netlink.c:1336
netlink_sendmsg+0x127f/0x1300 net/netlink/af_netlink.c:1917
sock_sendmsg_nosec net/socket.c:622 [inline]
sock_sendmsg net/socket.c:632 [inline]
Uninit was created at:
__alloc_skb+0x309/0xa20 net/core/skbuff.c:208
alloc_skb include/linux/skbuff.h:1012 [inline]
netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline]
netlink_sendmsg+0xb82/0x1300 net/netlink/af_netlink.c:1892
sock_sendmsg_nosec net/socket.c:622 [inline]
sock_sendmsg net/socket.c:632 [inline]
It was triggered when the bearer name size < TIPC_MAX_BEARER_NAME,
it would check with a wrong len/TLV_GET_DATA_LEN(msg->req), which
also includes priority and disc_domain length.
This patch is to fix it by checking it with a right length:
'TLV_GET_DATA_LEN(msg->req) - offsetof(struct tipc_bearer_config, name)'.
Reported-by: syzbot+8b707430713eb46e1e45@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/tipc/netlink_compat.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/net/tipc/netlink_compat.c b/net/tipc/netlink_compat.c index 4ad3586da8f0..5f8e53cca222 100644 --- a/net/tipc/netlink_compat.c +++ b/net/tipc/netlink_compat.c @@ -397,7 +397,12 @@ static int tipc_nl_compat_bearer_enable(struct tipc_nl_compat_cmd_doit *cmd, if (!bearer) return -EMSGSIZE; - len = min_t(int, TLV_GET_DATA_LEN(msg->req), TIPC_MAX_BEARER_NAME); + len = TLV_GET_DATA_LEN(msg->req); + len -= offsetof(struct tipc_bearer_config, name); + if (len <= 0) + return -EINVAL; + + len = min_t(int, len, TIPC_MAX_BEARER_NAME); if (!string_is_valid(b->name, len)) return -EINVAL; |