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authorMathias Krause <minipli@googlemail.com>2012-08-15 11:31:54 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-09-14 10:00:34 -0700
commitaf843972724e172827266e91ba326c069c8c088c (patch)
parent72961d91696071841fa013f11f686eaa7e2d0996 (diff)
dccp: check ccid before dereferencing
commit 276bdb82dedb290511467a5a4fdbe9f0b52dce6f upstream. 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> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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;