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authorJohannes Berg <johannes.berg@intel.com>2013-12-16 15:04:36 +0400
committerBen Hutchings <ben@decadent.org.uk>2014-02-15 23:20:13 +0400
commit39e87a9623c8b1fe690dccc18b885b56a2891aca (patch)
tree1df97d749e5861e51c17584555aa28be052b216e
parent50226b9992e79d43579b92650ecbfdbc1479980c (diff)
downloadlinux-39e87a9623c8b1fe690dccc18b885b56a2891aca.tar.xz
radiotap: fix bitmap-end-finding buffer overrun
commit bd02cd2549cfcdfc57cb5ce57ffc3feb94f70575 upstream. Evan Huus found (by fuzzing in wireshark) that the radiotap iterator code can access beyond the length of the buffer if the first bitmap claims an extension but then there's no data at all. Fix this. Reported-by: Evan Huus <eapache@gmail.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r--net/wireless/radiotap.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/net/wireless/radiotap.c b/net/wireless/radiotap.c
index 617a310025b1..60549a4a2f98 100644
--- a/net/wireless/radiotap.c
+++ b/net/wireless/radiotap.c
@@ -122,6 +122,10 @@ int ieee80211_radiotap_iterator_init(
/* find payload start allowing for extended bitmap(s) */
if (iterator->_bitmap_shifter & (1<<IEEE80211_RADIOTAP_EXT)) {
+ if ((unsigned long)iterator->_arg -
+ (unsigned long)iterator->_rtheader + sizeof(uint32_t) >
+ (unsigned long)iterator->_max_length)
+ return -EINVAL;
while (get_unaligned_le32(iterator->_arg) &
(1 << IEEE80211_RADIOTAP_EXT)) {
iterator->_arg += sizeof(uint32_t);