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wifi: intersil: hostap: Annotate struct prism2_download_data with __counted_by

PATCH In review Kees Cook 2 participants 2 messages Oct 6, 2023 P54 wireless driver

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Kees Cook

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PATCH 1/1 wifi: intersil: hostap: Annotate struct prism2_download_data with __counted_by

Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions).

As found with Coccinelle[1], add __counted_by for struct prism2_download_data.

Cc Kalle Valo <[email protected]>
Cc "Gustavo A. R. Silva" <[email protected]>
Cc [email protected]
Cc [email protected]
Link https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
Signed-off-by Kees Cook <[email protected]>
---
 drivers/net/wireless/intersil/hostap/hostap_wlan.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/net/wireless/intersil/hostap/hostap_wlan.h +1 -1
index c25cd21d18bd..f71c0545c0be 100644
@@ -617,7 +617,7 @@ struct prism2_download_data {
 		u32 addr; /* wlan card address */
 		u32 len;
 		u8 *data; /* allocated data */
-	} data[];
+	} data[] __counted_by(num_areas);
 };
Signature · 1 line
2.34.1
Reviewed-by on v1 1/1
#1 lore raw
Quoted 9 lines · Kees Cook

Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions).

As found with Coccinelle[1], add __counted_by for struct prism2_download_data.

Quoted 6 lines
Cc Kalle Valo <[email protected]>
Cc "Gustavo A. R. Silva" <[email protected]>
Cc [email protected]
Cc [email protected]
Link https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
Signed-off-by Kees Cook <[email protected]>
Reviewed-by Gustavo A. R. Silva <[email protected]>

Thanks!
--
Gustavo

Quoted 17 lines
---
  drivers/net/wireless/intersil/hostap/hostap_wlan.h | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)
drivers/net/wireless/intersil/hostap/hostap_wlan.h +1 -1
index c25cd21d18bd..f71c0545c0be 100644
@@ -617,7 +617,7 @@ struct prism2_download_data {
  		u32 addr; /* wlan card address */
  		u32 len;
  		u8 *data; /* allocated data */
-	} data[];
+	} data[] __counted_by(num_areas);
  };