2014-09-22 22:50:09

by Emil Goode

Subject: [PATCH v2] brcmfmac: Fix off by one bug in brcmf_count_20mhz_channels()

In the brcmf_count_20mhz_channels function we are looping through a list
of channels received from firmware. Since the index of the first channel
is 0 the condition leads to an off by one bug. This is causing us to hit
the WARN_ON_ONCE(1) calls in the brcmu_d11n_decchspec function, which is
how I discovered the bug.

Introduced by:
commit b48d891676f756d48b4d0ee131e4a7a5d43ca417
("brcmfmac: rework wiphy structure setup")

Acked-by: Arend van Spriel <[email protected]>
Signed-off-by: Emil Goode <[email protected]>
---
v2: Added Arends "Acked-by" tag.

drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c b/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c
index 12a60ca..0517687 100644
--- a/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c
+++ b/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c
@@ -4924,7 +4924,7 @@ static void brcmf_count_20mhz_channels(struct brcmf_cfg80211_info *cfg,
struct brcmu_chan ch;
int i;

- for (i = 0; i <= total; i++) {
+ for (i = 0; i < total; i++) {
ch.chspec = (u16)le32_to_cpu(chlist->element[i]);
cfg->d11inf.decchspec(&ch);

--
2.1.0

2014-09-23 09:10:11

by Arend van Spriel

Subject: Re: [PATCH v2] brcmfmac: Fix off by one bug in brcmf_count_20mhz_channels()

On 09/23/14 00:49, Emil Goode wrote:
> In the brcmf_count_20mhz_channels function we are looping through a list
> of channels received from firmware. Since the index of the first channel
> is 0 the condition leads to an off by one bug. This is causing us to hit
> the WARN_ON_ONCE(1) calls in the brcmu_d11n_decchspec function, which is
> how I discovered the bug.
>
> Introduced by:
> commit b48d891676f756d48b4d0ee131e4a7a5d43ca417
> ("brcmfmac: rework wiphy structure setup")
>

Hi John,

This bug was introduced in 3.17 so can it still go in the wireless tree?
I verified it applies to wireless/master branch.

Regards,
Arend

> Acked-by: Arend van Spriel<[email protected]>
> Signed-off-by: Emil Goode<[email protected]>
> ---
> v2: Added Arends "Acked-by" tag.
>
> drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c b/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c
> index 12a60ca..0517687 100644
> --- a/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c
> +++ b/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c
> @@ -4924,7 +4924,7 @@ static void brcmf_count_20mhz_channels(struct brcmf_cfg80211_info *cfg,
> struct brcmu_chan ch;
> int i;
>
> - for (i = 0; i<= total; i++) {
> + for (i = 0; i< total; i++) {
> ch.chspec = (u16)le32_to_cpu(chlist->element[i]);
> cfg->d11inf.decchspec(&ch);
>