From: Amitkumar Karwar <akarwar@xxxxxxxxxxx>
As tlv_buf_len is decremented at the end of the loop, we may have
accessed invalid memory in the last iteration.
Modify the while condition and add a break statement at the
begining of the loop to fix the problem.
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Amitkumar Karwar <akarwar@xxxxxxxxxxx>
Signed-off-by: Bing Zhao <bzhao@xxxxxxxxxxx>
---
drivers/net/wireless/mwifiex/sta_cmdresp.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)
diff --git a/drivers/net/wireless/mwifiex/sta_cmdresp.c b/drivers/net/wireless/mwifiex/sta_cmdresp.c
index 5edea4d..2675ca7 100644
--- a/drivers/net/wireless/mwifiex/sta_cmdresp.c
+++ b/drivers/net/wireless/mwifiex/sta_cmdresp.c
@@ -274,17 +274,20 @@ static int mwifiex_ret_tx_rate_cfg(struct mwifiex_private *priv,
struct host_cmd_ds_tx_rate_cfg *rate_cfg = &resp->params.tx_rate_cfg;
struct mwifiex_rate_scope *rate_scope;
struct mwifiex_ie_types_header *head;
- u16 tlv, tlv_buf_len;
+ u16 tlv, tlv_buf_len, tlv_buf_left;
u8 *tlv_buf;
u32 i;
- tlv_buf = ((u8 *)rate_cfg) +
- sizeof(struct host_cmd_ds_tx_rate_cfg);
- tlv_buf_len = le16_to_cpu(*(__le16 *) (tlv_buf + sizeof(u16)));
+ tlv_buf = ((u8 *)rate_cfg) + sizeof(struct host_cmd_ds_tx_rate_cfg);
+ tlv_buf_left = le16_to_cpu(resp->size) - S_DS_GEN - sizeof(*rate_cfg);
- while (tlv_buf && tlv_buf_len > 0) {
- tlv = (*tlv_buf);
- tlv = tlv | (*(tlv_buf + 1) << 8);
+ while (tlv_buf_left >= sizeof(*head)) {
+ head = (struct mwifiex_ie_types_header *)tlv_buf;
+ tlv = le16_to_cpu(head->type);
+ tlv_buf_len = le16_to_cpu(head->len);
+
+ if (tlv_buf_left < (sizeof(*head) + tlv_buf_len))
+ break;
switch (tlv) {
case TLV_TYPE_RATE_SCOPE:
@@ -304,9 +307,8 @@ static int mwifiex_ret_tx_rate_cfg(struct mwifiex_private *priv,
/* Add RATE_DROP tlv here */
}
- head = (struct mwifiex_ie_types_header *) tlv_buf;
- tlv_buf += le16_to_cpu(head->len) + sizeof(*head);
- tlv_buf_len -= le16_to_cpu(head->len);
+ tlv_buf += (sizeof(*head) + tlv_buf_len);
+ tlv_buf_left -= (sizeof(*head) + tlv_buf_len);
}
priv->is_data_rate_auto = mwifiex_is_rate_auto(priv);
--
1.8.2.3
--
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