4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Arend Van Spriel <arend.vanspriel@xxxxxxxxxxxx>
commit 17df6453d4be17910456e99c5a85025aa1b7a246 upstream.
Upon handling the firmware notification for scans the length was
checked properly and may result in corrupting kernel heap memory
due to buffer overruns. This fix addresses CVE-2017-0786.
Cc: Kevin Cernekee <cernekee@xxxxxxxxxxxx>
Reviewed-by: Hante Meuleman <hante.meuleman@xxxxxxxxxxxx>
Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@xxxxxxxxxxxx>
Reviewed-by: Franky Lin <franky.lin@xxxxxxxxxxxx>
Signed-off-by: Arend van Spriel <arend.vanspriel@xxxxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/wireless/brcm80211/brcmfmac/cfg80211.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)
--- a/drivers/net/wireless/brcm80211/brcmfmac/cfg80211.c
+++ b/drivers/net/wireless/brcm80211/brcmfmac/cfg80211.c
@@ -2903,6 +2903,7 @@ brcmf_cfg80211_escan_handler(struct brcm
struct brcmf_cfg80211_info *cfg = ifp->drvr->config;
s32 status;
struct brcmf_escan_result_le *escan_result_le;
+ u32 escan_buflen;
struct brcmf_bss_info_le *bss_info_le;
struct brcmf_bss_info_le *bss = NULL;
u32 bi_length;
@@ -2919,11 +2920,23 @@ brcmf_cfg80211_escan_handler(struct brcm
if (status == BRCMF_E_STATUS_PARTIAL) {
brcmf_dbg(SCAN, "ESCAN Partial result\n");
+ if (e->datalen < sizeof(*escan_result_le)) {
+ brcmf_err("invalid event data length\n");
+ goto exit;
+ }
escan_result_le = (struct brcmf_escan_result_le *) data;
if (!escan_result_le) {
brcmf_err("Invalid escan result (NULL pointer)\n");
goto exit;
}
+ escan_buflen = le32_to_cpu(escan_result_le->buflen);
+ if (escan_buflen > WL_ESCAN_BUF_SIZE ||
+ escan_buflen > e->datalen ||
+ escan_buflen < sizeof(*escan_result_le)) {
+ brcmf_err("Invalid escan buffer length: %d\n",
+ escan_buflen);
+ goto exit;
+ }
if (le16_to_cpu(escan_result_le->bss_count) != 1) {
brcmf_err("Invalid bss_count %d: ignoring\n",
escan_result_le->bss_count);
@@ -2940,9 +2953,8 @@ brcmf_cfg80211_escan_handler(struct brcm
}
bi_length = le32_to_cpu(bss_info_le->length);
- if (bi_length != (le32_to_cpu(escan_result_le->buflen) -
- WL_ESCAN_RESULTS_FIXED_SIZE)) {
- brcmf_err("Invalid bss_info length %d: ignoring\n",
+ if (bi_length != escan_buflen - WL_ESCAN_RESULTS_FIXED_SIZE) {
+ brcmf_err("Ignoring invalid bss_info length: %d\n",
bi_length);
goto exit;
}