From: Antonio Quartulli <[email protected]>
ovpn_peer_endpoints_update() builds the new remote endpoint in an
on-stack struct sockaddr_storage that is left uninitialized. For IPv4
only sin_family/sin_addr/sin_port are written, leaving the 8-byte
sin_zero padding as stack garbage (for IPv6, sin6_flowinfo is left
uninitialized likewise).
ovpn_peer_reset_sockaddr() -> ovpn_bind_from_sockaddr() then memcpy()s
sizeof(struct sockaddr_in)/sizeof(struct sockaddr_in6) bytes - padding
included - into bind->remote. That buffer is later hashed with jhash()
over the same length to place the peer in the by_transp_addr table, so
the garbage padding lands the floated peer in an essentially random
bucket. Lockless lookups in ovpn_peer_get_by_transp_addr() build their
key from a zero-initialized sockaddr_storage, compute a different bucket
and fail to find the peer.
This is also a plain use of uninitialized stack memory in jhash().
Zero-initialize the sockaddr_storage, matching what the lookup and
netlink paths already do.
Fixes: f0281c1d3732 ("ovpn: add support for updating local or remote UDP
endpoint")
Signed-off-by: Antonio Quartulli <[email protected]>
---
drivers/net/ovpn/peer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ovpn/peer.c b/drivers/net/ovpn/peer.c
index bbb1946fa5b4..1d878c3e1514 100644
--- a/drivers/net/ovpn/peer.c
+++ b/drivers/net/ovpn/peer.c
@@ -220,7 +220,7 @@ static void __ovpn_peer_hash_transp_addr(struct ovpn_peer
*peer,
*/
void ovpn_peer_endpoints_update(struct ovpn_peer *peer, struct sk_buff *skb)
{
- struct sockaddr_storage ss;
+ struct sockaddr_storage ss = {};
struct sockaddr_in6 *sa6;
bool reset_cache = false;
struct sockaddr_in *sa;
--
2.53.0
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