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| author | Sean Tranchetti <stranche@codeaurora.org> | 2018-09-20 14:29:45 -0600 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-09-21 18:58:34 -0700 |
| commit | f88b4c01b97e09535505cf3c327fdbce55c27f00 (patch) | |
| tree | ec1b78cc89f9d23fdbd1e3abaea8dd6357648abf /net/netlabel | |
| parent | 652ef42c134da1bbb03bd4c9b4291dfaf8d7febb (diff) | |
| download | lwn-f88b4c01b97e09535505cf3c327fdbce55c27f00.tar.gz lwn-f88b4c01b97e09535505cf3c327fdbce55c27f00.zip | |
netlabel: check for IPV4MASK in addrinfo_get
netlbl_unlabel_addrinfo_get() assumes that if it finds the
NLBL_UNLABEL_A_IPV4ADDR attribute, it must also have the
NLBL_UNLABEL_A_IPV4MASK attribute as well. However, this is
not necessarily the case as the current checks in
netlbl_unlabel_staticadd() and friends are not sufficent to
enforce this.
If passed a netlink message with NLBL_UNLABEL_A_IPV4ADDR,
NLBL_UNLABEL_A_IPV6ADDR, and NLBL_UNLABEL_A_IPV6MASK attributes,
these functions will all call netlbl_unlabel_addrinfo_get() which
will then attempt dereference NULL when fetching the non-existent
NLBL_UNLABEL_A_IPV4MASK attribute:
Unable to handle kernel NULL pointer dereference at virtual address 0
Process unlab (pid: 31762, stack limit = 0xffffff80502d8000)
Call trace:
netlbl_unlabel_addrinfo_get+0x44/0xd8
netlbl_unlabel_staticremovedef+0x98/0xe0
genl_rcv_msg+0x354/0x388
netlink_rcv_skb+0xac/0x118
genl_rcv+0x34/0x48
netlink_unicast+0x158/0x1f0
netlink_sendmsg+0x32c/0x338
sock_sendmsg+0x44/0x60
___sys_sendmsg+0x1d0/0x2a8
__sys_sendmsg+0x64/0xb4
SyS_sendmsg+0x34/0x4c
el0_svc_naked+0x34/0x38
Code: 51001149 7100113f 540000a0 f9401508 (79400108)
---[ end trace f6438a488e737143 ]---
Kernel panic - not syncing: Fatal exception
Signed-off-by: Sean Tranchetti <stranche@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/netlabel')
| -rw-r--r-- | net/netlabel/netlabel_unlabeled.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c index c070dfc0190a..c92894c3e40a 100644 --- a/net/netlabel/netlabel_unlabeled.c +++ b/net/netlabel/netlabel_unlabeled.c @@ -781,7 +781,8 @@ static int netlbl_unlabel_addrinfo_get(struct genl_info *info, { u32 addr_len; - if (info->attrs[NLBL_UNLABEL_A_IPV4ADDR]) { + if (info->attrs[NLBL_UNLABEL_A_IPV4ADDR] && + info->attrs[NLBL_UNLABEL_A_IPV4MASK]) { addr_len = nla_len(info->attrs[NLBL_UNLABEL_A_IPV4ADDR]); if (addr_len != sizeof(struct in_addr) && addr_len != nla_len(info->attrs[NLBL_UNLABEL_A_IPV4MASK])) |