From d5fa96dc5590915f060fee3209143313e4f5b03b Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 10 Jun 2025 11:32:52 +0200 Subject: [PATCH] crypto: arm/aes-neonbs - work around gcc-15 warning I get a very rare -Wstringop-overread warning with gcc-15 for one function in aesbs_ctr_encrypt(): arch/arm/crypto/aes-neonbs-glue.c: In function 'ctr_encrypt': arch/arm/crypto/aes-neonbs-glue.c:212:1446: error: '__builtin_memcpy' offset [17, 2147483647] is out of the bounds [0, 16] of object 'buf' with type 'u8[16]' {aka 'unsigned char[16]'} [-Werror=array-bounds=] 212 | src = dst = memcpy(buf + sizeof(buf) - bytes, arch/arm/crypto/aes-neonbs-glue.c: In function 'ctr_encrypt': arch/arm/crypto/aes-neonbs-glue.c:218:17: error: 'aesbs_ctr_encrypt' reading 1 byte from a region of size 0 [-Werror=stringop-overread] 218 | aesbs_ctr_encrypt(dst, src, ctx->rk, ctx->rounds, bytes, walk.iv); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/arm/crypto/aes-neonbs-glue.c:218:17: note: referencing argument 2 of type 'const u8[0]' {aka 'const unsigned char[]'} arch/arm/crypto/aes-neonbs-glue.c:218:17: note: referencing argument 3 of type 'const u8[0]' {aka 'const unsigned char[]'} arch/arm/crypto/aes-neonbs-glue.c:218:17: note: referencing argument 6 of type 'u8[0]' {aka 'unsigned char[]'} arch/arm/crypto/aes-neonbs-glue.c:36:17: note: in a call to function 'aesbs_ctr_encrypt' 36 | asmlinkage void aesbs_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[], This could happen in theory if walk.nbytes is larger than INT_MAX and gets converted to a negative local variable. Keep the type unsigned like the orignal nbytes to be sure there is no integer overflow. Fixes: c8bf850e991a ("crypto: arm/aes-neonbs-ctr - deal with non-multiples of AES block size") Signed-off-by: Arnd Bergmann Acked-by: Ard Biesheuvel Signed-off-by: Herbert Xu --- arch/arm/crypto/aes-neonbs-glue.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/crypto/aes-neonbs-glue.c b/arch/arm/crypto/aes-neonbs-glue.c index c60104dc15852..df5afe601e4a5 100644 --- a/arch/arm/crypto/aes-neonbs-glue.c +++ b/arch/arm/crypto/aes-neonbs-glue.c @@ -206,7 +206,7 @@ static int ctr_encrypt(struct skcipher_request *req) while (walk.nbytes > 0) { const u8 *src = walk.src.virt.addr; u8 *dst = walk.dst.virt.addr; - int bytes = walk.nbytes; + unsigned int bytes = walk.nbytes; if (unlikely(bytes < AES_BLOCK_SIZE)) src = dst = memcpy(buf + sizeof(buf) - bytes, -- 2.47.2