6.15-stable review patch. If anyone has any objections, please let me know.
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From: Arnd Bergmann arnd@arndb.de
[ Upstream commit d5fa96dc5590915f060fee3209143313e4f5b03b ]
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 arnd@arndb.de Acked-by: Ard Biesheuvel ardb@kernel.org Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Sasha Levin sashal@kernel.org --- 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 f6be80b5938b..2fad3a0c0563 100644 --- a/arch/arm/crypto/aes-neonbs-glue.c +++ b/arch/arm/crypto/aes-neonbs-glue.c @@ -232,7 +232,7 @@ 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,