Messages in this thread Patch in this message | | | From | Mathias Krause <> | Subject | [PATCH 11/14] dccp: check ccid before dereferencing | Date | Wed, 15 Aug 2012 23:31:54 +0200 |
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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 --- net/dccp/ccid.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/dccp/ccid.h b/net/dccp/ccid.h index 75c3582..fb85d37 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; -- 1.7.10.4
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