From bd02cd2549cfcdfc57cb5ce57ffc3feb94f70575 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Mon, 16 Dec 2013 12:04:36 +0100 Subject: radiotap: fix bitmap-end-finding buffer overrun 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. Cc: stable@vger.kernel.org Reported-by: Evan Huus Signed-off-by: Johannes Berg --- net/wireless/radiotap.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/wireless/radiotap.c b/net/wireless/radiotap.c index a271c27fac77..722da616438c 100644 --- a/net/wireless/radiotap.c +++ b/net/wireless/radiotap.c @@ -124,6 +124,10 @@ int ieee80211_radiotap_iterator_init( /* find payload start allowing for extended bitmap(s) */ if (iterator->_bitmap_shifter & (1<_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); -- cgit v1.2.3