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authorMathias Krause <minipli@googlemail.com>2012-08-15 11:31:54 +0000
committerDavid S. Miller <davem@davemloft.net>2012-08-15 21:36:31 -0700
commit276bdb82dedb290511467a5a4fdbe9f0b52dce6f (patch)
tree0882e07c971f4254c5fe07c0e3eefadb8c6cfda0
parent3592aaeb80290bda0f2cf0b5456c97bfc638b192 (diff)
dccp: check ccid before dereferencing
ccid_hc_rx_getsockopt() and ccid_hc_tx_getsockopt() might be called with a NULL ccid pointer leading to a NULL pointer dereference. This could lead to a privilege escalation if the attacker is able to map page 0 and prepare it with a fake ccid_ops pointer. Signed-off-by: Mathias Krause <minipli@googlemail.com> Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk> Cc: stable@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/dccp/ccid.h4
1 files changed, 2 insertions, 2 deletions
diff --git a/net/dccp/ccid.h b/net/dccp/ccid.h
index 75c3582a7678..fb85d371a8de 100644
--- a/net/dccp/ccid.h
+++ b/net/dccp/ccid.h
@@ -246,7 +246,7 @@ static inline int ccid_hc_rx_getsockopt(struct ccid *ccid, struct sock *sk,
u32 __user *optval, int __user *optlen)
{
int rc = -ENOPROTOOPT;
- if (ccid->ccid_ops->ccid_hc_rx_getsockopt != NULL)
+ if (ccid != NULL && ccid->ccid_ops->ccid_hc_rx_getsockopt != NULL)
rc = ccid->ccid_ops->ccid_hc_rx_getsockopt(sk, optname, len,
optval, optlen);
return rc;
@@ -257,7 +257,7 @@ static inline int ccid_hc_tx_getsockopt(struct ccid *ccid, struct sock *sk,
u32 __user *optval, int __user *optlen)
{
int rc = -ENOPROTOOPT;
- if (ccid->ccid_ops->ccid_hc_tx_getsockopt != NULL)
+ if (ccid != NULL && ccid->ccid_ops->ccid_hc_tx_getsockopt != NULL)
rc = ccid->ccid_ops->ccid_hc_tx_getsockopt(sk, optname, len,
optval, optlen);
return rc;