ath10k: add sanity check to ie_len before parsing fw/board ie

Commit Message

Ryan Hsu Jan. 8, 2018, 11:51 p.m. UTC

From: Ryan Hsu <[e-mail]>

Validate ie_len after the alignment padding before access the buffer
to avoid potential overflow.

Signed-off-by: Ryan Hsu <[e-mail]>
---
 drivers/net/wireless/ath/ath10k/core.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

Comments

Kalle Valo Jan. 16, 2018, 2:31 p.m. UTC | #1

[e-mail] wrote:

> Validate ie_len after the alignment padding before access the buffer
> to avoid potential overflow.
> 
> Signed-off-by: Ryan Hsu <[e-mail]>
> Signed-off-by: Kalle Valo <[e-mail]>

Patch applied to ath-next branch of ath.git, thanks.

9ed4f9162873 ath10k: add sanity check to ie_len before parsing fw/board ie

Patch

diff --git a/drivers/net/wireless/ath/ath10k/core.c b/drivers/net/wireless/ath/ath10k/core.c
index 51444d3..64713d1 100644
--- a/drivers/net/wireless/ath/ath10k/core.c
+++ b/drivers/net/wireless/ath/ath10k/core.c
@@ -1276,7 +1276,10 @@  static int ath10k_core_fetch_board_data_api_n(struct ath10k *ar,
 		len -= sizeof(*hdr);
 		data = hdr->data;
 
-		if (len < ALIGN(ie_len, 4)) {
+		/* jump over the padding */
+		ie_len = ALIGN(ie_len, 4);
+
+		if (len < ie_len) {
 			ath10k_err(ar, "invalid length for board ie_id %d ie_len %zu len %zu\n",
 				   ie_id, ie_len, len);
 			ret = -EINVAL;
@@ -1315,8 +1318,6 @@  static int ath10k_core_fetch_board_data_api_n(struct ath10k *ar,
 			goto out;
 		}
 
-		/* jump over the padding */
-		ie_len = ALIGN(ie_len, 4);
 
 		len -= ie_len;
 		data += ie_len;
@@ -1448,6 +1449,9 @@  int ath10k_core_fetch_firmware_api_n(struct ath10k *ar, const char *name,
 		len -= sizeof(*hdr);
 		data += sizeof(*hdr);
 
+		/* jump over the padding */
+		ie_len = ALIGN(ie_len, 4);
+
 		if (len < ie_len) {
 			ath10k_err(ar, "invalid length for FW IE %d (%zu < %zu)\n",
 				   ie_id, len, ie_len);
@@ -1553,9 +1557,6 @@  int ath10k_core_fetch_firmware_api_n(struct ath10k *ar, const char *name,
 			break;
 		}
 
-		/* jump over the padding */
-		ie_len = ALIGN(ie_len, 4);
-
 		len -= ie_len;
 		data += ie_len;
 	}