Commit 47f76ca3 authored by Michael Buesch's avatar Michael Buesch Committed by David S. Miller
Browse files

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: default avatarMichael Buesch <mb@bu3sch.de>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 280d0e16
......@@ -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)
......
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