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authorJohannes Berg <johannes.berg@intel.com>2013-10-11 14:47:05 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-11-04 04:23:42 -0800
commit5b81d479d6b12a0c44e261de0e454ed740c7f81d (patch)
tree42023e79e4327230580502195e9df88baa9b06c8
parent60c6aa3ad74360adfaa171598a0ea9d0783ad532 (diff)
downloadlwn-5b81d479d6b12a0c44e261de0e454ed740c7f81d.tar.gz
lwn-5b81d479d6b12a0c44e261de0e454ed740c7f81d.zip
wireless: radiotap: fix parsing buffer overrun
commit f5563318ff1bde15b10e736e97ffce13be08bc1a upstream. When parsing an invalid radiotap header, the parser can overrun the buffer that is passed in because it doesn't correctly check 1) the minimum radiotap header size 2) the space for extended bitmaps The first issue doesn't affect any in-kernel user as they all check the minimum size before calling the radiotap function. The second issue could potentially affect the kernel if an skb is passed in that consists only of the radiotap header with a lot of extended bitmaps that extend past the SKB. In that case a read-only buffer overrun by at most 4 bytes is possible. Fix this by adding the appropriate checks to the parser. Reported-by: Evan Huus <eapache@gmail.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/wireless/radiotap.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/net/wireless/radiotap.c b/net/wireless/radiotap.c
index c4ad7958af52..617a310025b1 100644
--- a/net/wireless/radiotap.c
+++ b/net/wireless/radiotap.c
@@ -95,6 +95,10 @@ int ieee80211_radiotap_iterator_init(
struct ieee80211_radiotap_header *radiotap_header,
int max_length, const struct ieee80211_radiotap_vendor_namespaces *vns)
{
+ /* check the radiotap header can actually be present */
+ if (max_length < sizeof(struct ieee80211_radiotap_header))
+ return -EINVAL;
+
/* Linux only supports version 0 radiotap format */
if (radiotap_header->it_version)
return -EINVAL;
@@ -129,7 +133,8 @@ int ieee80211_radiotap_iterator_init(
*/
if ((unsigned long)iterator->_arg -
- (unsigned long)iterator->_rtheader >
+ (unsigned long)iterator->_rtheader +
+ sizeof(uint32_t) >
(unsigned long)iterator->_max_length)
return -EINVAL;
}