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ray_cs: Avoid reading past end of buffer

PATCH In review Kees Cook 2 participants 2 messages May 5, 2017 – May 22, 2017

Subsystems (3)
Networking Network drivers Networking drivers (wireless)
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Kees Cook

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#0 lore raw

PATCH 1/1 ray_cs: Avoid reading past end of buffer

Using memcpy() from a buffer that is shorter than the length copied means the destination buffer is being filled with arbitrary data from the kernel rodata segment. In this case, the source was made longer, since it did not match the destination structure size. Additionally removes a needless cast.

This was found with the future CONFIG_FORTIFY_SOURCE feature.

Cc Daniel Micay <[email protected]>
Signed-off-by Kees Cook <[email protected]>
---
 drivers/net/wireless/ray_cs.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
drivers/net/wireless/ray_cs.c +5 -2
index b94479441b0c..170cd504e8ff 100644
@@ -247,7 +247,10 @@ static const UCHAR b4_default_startup_parms[] = {
 	0x04, 0x08,		/* Noise gain, limit offset */
 	0x28, 0x28,		/* det rssi, med busy offsets */
 	7,			/* det sync thresh */
-	0, 2, 2			/* test mode, min, max */
+	0, 2, 2,		/* test mode, min, max */
+	0,			/* rx/tx delay */
+	0, 0, 0, 0, 0, 0,	/* current BSS id */
+	0			/* hop set */
 };
 
 /*===========================================================================*/

@@ -597,7 +600,7 @@ static void init_startup_params(ray_dev_t *local)
 	 *    a_beacon_period = hops    a_beacon_period = KuS
 	 *//* 64ms = 010000 */
 	if (local->fw_ver == 0x55) {
-		memcpy((UCHAR *) &local->sparm.b4, b4_default_startup_parms,
+		memcpy(&local->sparm.b4, b4_default_startup_parms,
 		       sizeof(struct b4_startup_params));
 		/* Translate sane kus input values to old build 4/5 format */
 		/* i = hop time in uS truncated to 3 bytes */
Signature · 6 lines
2.7.4


-- 
Kees Cook
Pixel Security
#1 lore raw
Quoted 9 lines · Kees Cook

Using memcpy() from a buffer that is shorter than the length copied means the destination buffer is being filled with arbitrary data from the kernel rodata segment. In this case, the source was made longer, since it did not match the destination structure size. Additionally removes a needless cast.

This was found with the future CONFIG_FORTIFY_SOURCE feature.

Cc Daniel Micay <[email protected]>
Signed-off-by Kees Cook <[email protected]>

Patch applied to wireless-drivers-next.git, thanks.

e48d661eb13f ray_cs: Avoid reading past end of buffer

Signature · 3 lines
https://patchwork.kernel.org/patch/9714453/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches