| Message ID | 20250610093256.2645686-1-arnd@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | ARM: crypto: work around gcc-15 warning | expand |
On Tue, 10 Jun 2025 at 11:33, Arnd Bergmann <arnd@kernel.org> wrote: > > From: Arnd Bergmann <arnd@arndb.de> > > 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> > --- > 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 c60104dc1585..df5afe601e4a 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, > -- > 2.39.5 >
diff --git a/arch/arm/crypto/aes-neonbs-glue.c b/arch/arm/crypto/aes-neonbs-glue.c index c60104dc1585..df5afe601e4a 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,