From 47f76ca3a34cd6571a2de39da2926123ca39a4c1 Mon Sep 17 00:00:00 2001 From: Michael Buesch Date: Thu, 27 Dec 2007 22:15:11 +0100 Subject: b43: Fix tim search buffer overrun Use the length of the variable section of the beacon instead of the whole beacon length for bounds checking. Signed-off-by: Michael Buesch Signed-off-by: John W. Linville --- drivers/net/wireless/b43/main.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'drivers') diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c index 345ac3862e1..a15a45b789b 100644 --- a/drivers/net/wireless/b43/main.c +++ b/drivers/net/wireless/b43/main.c @@ -1163,7 +1163,7 @@ static void b43_write_beacon_template(struct b43_wldev *dev, u16 ram_offset, u16 shm_size_offset, u8 rate) { - int i, len; + unsigned int i, len, variable_len; const struct ieee80211_mgmt *bcn; const u8 *ie; bool tim_found = 0; @@ -1178,7 +1178,8 @@ static void b43_write_beacon_template(struct b43_wldev *dev, /* Find the position of the TIM and the DTIM_period value * and write them to SHM. */ ie = bcn->u.beacon.variable; - for (i = 0; i < len - 2; ) { + variable_len = len - offsetof(struct ieee80211_mgmt, u.beacon.variable); + for (i = 0; i < variable_len - 2; ) { uint8_t ie_id, ie_len; ie_id = ie[i]; @@ -1189,7 +1190,7 @@ static void b43_write_beacon_template(struct b43_wldev *dev, /* This is the TIM Information Element */ /* Check whether the ie_len is in the beacon data range. */ - if (len < ie_len + 2 + i) + if (variable_len < ie_len + 2 + i) break; /* A valid TIM is at least 4 bytes long. */ if (ie_len < 4) -- cgit v1.2.3