* [PATCH] wl1251: Fix possible buffer overflow in wl1251_cmd_scan
@ 2021-03-17 12:18 Lee Gibson
2021-04-18 6:54 ` Kalle Valo
2021-04-28 11:55 ` [PATCH v2] " Lee Gibson
0 siblings, 2 replies; 4+ messages in thread
From: Lee Gibson @ 2021-03-17 12:18 UTC (permalink / raw)
To: kvalo; +Cc: davem, kuba, linux-wireless, netdev, linux-kernel, Lee Gibson
Function wl1251_cmd_scan calls memcpy without checking the length.
A user could control that length and trigger a buffer overflow.
Fix by checking the length is within the maximum allowed size.
Signed-off-by: Lee Gibson <leegib@gmail.com>
---
drivers/net/wireless/ti/wl1251/cmd.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/ti/wl1251/cmd.c b/drivers/net/wireless/ti/wl1251/cmd.c
index 498c8db2eb48..e4d028a53d91 100644
--- a/drivers/net/wireless/ti/wl1251/cmd.c
+++ b/drivers/net/wireless/ti/wl1251/cmd.c
@@ -455,8 +455,11 @@ int wl1251_cmd_scan(struct wl1251 *wl, u8 *ssid, size_t ssid_len,
}
cmd->params.ssid_len = ssid_len;
- if (ssid)
- memcpy(cmd->params.ssid, ssid, ssid_len);
+ if (ssid) {
+ int len = min_t(int, ssid_len, IEEE80211_MAX_SSID_LEN);
+
+ memcpy(cmd->params.ssid, ssid, len);
+ }
ret = wl1251_cmd_send(wl, CMD_SCAN, cmd, sizeof(*cmd));
if (ret < 0) {
--
2.25.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] wl1251: Fix possible buffer overflow in wl1251_cmd_scan
2021-03-17 12:18 [PATCH] wl1251: Fix possible buffer overflow in wl1251_cmd_scan Lee Gibson
@ 2021-04-18 6:54 ` Kalle Valo
2021-04-28 11:55 ` [PATCH v2] " Lee Gibson
1 sibling, 0 replies; 4+ messages in thread
From: Kalle Valo @ 2021-04-18 6:54 UTC (permalink / raw)
To: Lee Gibson; +Cc: davem, kuba, linux-wireless, netdev, linux-kernel
Lee Gibson <leegib@gmail.com> writes:
> Function wl1251_cmd_scan calls memcpy without checking the length.
> A user could control that length and trigger a buffer overflow.
> Fix by checking the length is within the maximum allowed size.
>
> Signed-off-by: Lee Gibson <leegib@gmail.com>
Please fix the commit log, the user cannot control this length as
cfg80211 checks it before handling it to wl1251. Unless I'm missing
something.
> ---
> drivers/net/wireless/ti/wl1251/cmd.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/ti/wl1251/cmd.c b/drivers/net/wireless/ti/wl1251/cmd.c
> index 498c8db2eb48..e4d028a53d91 100644
> --- a/drivers/net/wireless/ti/wl1251/cmd.c
> +++ b/drivers/net/wireless/ti/wl1251/cmd.c
> @@ -455,8 +455,11 @@ int wl1251_cmd_scan(struct wl1251 *wl, u8 *ssid, size_t ssid_len,
> }
>
> cmd->params.ssid_len = ssid_len;
If you are checking the length, you should also check ssid_len here.
> - if (ssid)
> - memcpy(cmd->params.ssid, ssid, ssid_len);
> + if (ssid) {
> + int len = min_t(int, ssid_len, IEEE80211_MAX_SSID_LEN);
> +
> + memcpy(cmd->params.ssid, ssid, len);
> + }
Please use clamp_val().
Also another (and IMHO better) way to cleanup this is to provide a
pointer to struct cfg80211_ssid, which makes it clear that the length
can be trusted and not length checking is not needed. So something like
this:
int wl1251_cmd_scan(struct wl1251 *wl, const struct cfg80211_ssid *ssid,
struct ieee80211_channel *channels[],
unsigned int n_channels, unsigned int n_probes)
--
https://patchwork.kernel.org/project/linux-wireless/list/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
^ permalink raw reply [flat|nested] 4+ messages in thread* [PATCH v2] wl1251: Fix possible buffer overflow in wl1251_cmd_scan
2021-03-17 12:18 [PATCH] wl1251: Fix possible buffer overflow in wl1251_cmd_scan Lee Gibson
2021-04-18 6:54 ` Kalle Valo
@ 2021-04-28 11:55 ` Lee Gibson
2021-06-15 13:36 ` Kalle Valo
1 sibling, 1 reply; 4+ messages in thread
From: Lee Gibson @ 2021-04-28 11:55 UTC (permalink / raw)
To: kvalo; +Cc: davem, kuba, linux-wireless, netdev, linux-kernel, Lee Gibson
Function wl1251_cmd_scan calls memcpy without checking the length.
Harden by checking the length is within the maximum allowed size.
Signed-off-by: Lee Gibson <leegib@gmail.com>
---
v2: use clamp_val() instead of min_t()
drivers/net/wireless/ti/wl1251/cmd.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/net/wireless/ti/wl1251/cmd.c b/drivers/net/wireless/ti/wl1251/cmd.c
index 498c8db2eb48..d7a869106782 100644
--- a/drivers/net/wireless/ti/wl1251/cmd.c
+++ b/drivers/net/wireless/ti/wl1251/cmd.c
@@ -454,9 +454,12 @@ int wl1251_cmd_scan(struct wl1251 *wl, u8 *ssid, size_t ssid_len,
cmd->channels[i].channel = channels[i]->hw_value;
}
- cmd->params.ssid_len = ssid_len;
- if (ssid)
- memcpy(cmd->params.ssid, ssid, ssid_len);
+ if (ssid) {
+ int len = clamp_val(ssid_len, 0, IEEE80211_MAX_SSID_LEN);
+
+ cmd->params.ssid_len = len;
+ memcpy(cmd->params.ssid, ssid, len);
+ }
ret = wl1251_cmd_send(wl, CMD_SCAN, cmd, sizeof(*cmd));
if (ret < 0) {
--
2.25.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-06-15 13:36 UTC | newest]
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2021-03-17 12:18 [PATCH] wl1251: Fix possible buffer overflow in wl1251_cmd_scan Lee Gibson
2021-04-18 6:54 ` Kalle Valo
2021-04-28 11:55 ` [PATCH v2] " Lee Gibson
2021-06-15 13:36 ` Kalle Valo
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