staging: rtl8192e: Annotate struct rtllib_txb 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 checking 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 rtllib_txb.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Greg Kroah-Hartman <[email protected]>
Cc: Philipp Hortmann <[email protected]>
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: "Gustavo A. R. Silva" <[email protected]>
Tested-by: Philipp Hortmann <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

diff --git a/drivers/staging/rtl8192e/rtllib.h b/drivers/staging/rtl8192e/rtllib.h
index afde4812a221b903e8fac1acefac017a79933d38..bfa4dbf94d605a38492fae864ab5929d9d0db6be 100644 (file)
--- a/drivers/staging/rtl8192e/rtllib.h
+++ b/drivers/staging/rtl8192e/rtllib.h
@@ -814,7 +814,7 @@ struct rtllib_txb {
        u16 reserved;
        __le16 frag_size;
        __le16 payload_size;
-       struct sk_buff *fragments[];
+       struct sk_buff *fragments[] __counted_by(nr_frags);
 };
 
 #define MAX_SUBFRAME_COUNT               64