[PATCH wireless-next] brcmsmac: avoid 512 byte stack variable

From: Tim Gardner
Date: Thu Feb 07 2013 - 15:14:21 EST


Dynamically allocate the probe response template which
avoids potential stack corruption. Observed with smatch:

drivers/net/wireless/brcm80211/brcmsmac/main.c:7412 brcms_c_bss_update_probe_resp()
warn: 'prb_resp' puts 512 bytes on stack

Cc: Brett Rudley <brudley@xxxxxxxxxxxx>
Cc: Arend van Spriel <arend@xxxxxxxxxxxx>
Cc: "Franky (Zhenhui) Lin" <frankyl@xxxxxxxxxxxx>
Cc: Hante Meuleman <meuleman@xxxxxxxxxxxx>
Cc: "John W. Linville" <linville@xxxxxxxxxxxxx>
Cc: Seth Forshee <seth.forshee@xxxxxxxxxxxxx>
Cc: Pieter-Paul Giesberts <pieterpg@xxxxxxxxxxxx>
Cc: Hauke Mehrtens <hauke@xxxxxxxxxx>
Cc: linux-wireless@xxxxxxxxxxxxxxx
Cc: brcm80211-dev-list@xxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
Signed-off-by: Tim Gardner <tim.gardner@xxxxxxxxxxxxx>
---
drivers/net/wireless/brcm80211/brcmsmac/main.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/brcm80211/brcmsmac/main.c b/drivers/net/wireless/brcm80211/brcmsmac/main.c
index c26992a..e392e76 100644
--- a/drivers/net/wireless/brcm80211/brcmsmac/main.c
+++ b/drivers/net/wireless/brcm80211/brcmsmac/main.c
@@ -7408,9 +7408,16 @@ brcms_c_bss_update_probe_resp(struct brcms_c_info *wlc,
struct brcms_bss_cfg *cfg,
bool suspend)
{
- u16 prb_resp[BCN_TMPL_LEN / 2];
+ u16 *prb_resp;
int len = BCN_TMPL_LEN;

+ prb_resp = kmalloc(BCN_TMPL_LEN, GFP_ATOMIC);
+ if (!prb_resp) {
+ wiphy_err(wlc->wiphy, "wl: %s: failed to alloc %u bytes\n",
+ __func__, BCN_TMPL_LEN);
+ return;
+ }
+
/*
* write the probe response to hardware, or save in
* the config structure
@@ -7444,6 +7451,8 @@ brcms_c_bss_update_probe_resp(struct brcms_c_info *wlc,

if (suspend)
brcms_c_enable_mac(wlc);
+
+ kfree(prb_resp);
}

void brcms_c_update_probe_resp(struct brcms_c_info *wlc, bool suspend)
--
1.7.9.5

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