On Fri, Aug 11, 2023 at 03:46:33PM +0200, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@xxxxxxxx> > > Some configurations with gcc-12 or gcc-13 produce a warning for the source > and destination of a memcpy() in atmel_sha_hmac_compute_ipad_hash() potentially > overlapping: > > In file included from include/linux/string.h:254, > from drivers/crypto/atmel-sha.c:15: > drivers/crypto/atmel-sha.c: In function 'atmel_sha_hmac_compute_ipad_hash': > include/linux/fortify-string.h:57:33: error: '__builtin_memcpy' accessing 129 or more bytes at offsets 408 and 280 overlaps 1 or more bytes at offset 408 [-Werror=restrict] > 57 | #define __underlying_memcpy __builtin_memcpy > | ^ > include/linux/fortify-string.h:648:9: note: in expansion of macro '__underlying_memcpy' > 648 | __underlying_##op(p, q, __fortify_size); \ > | ^~~~~~~~~~~~~ > include/linux/fortify-string.h:693:26: note: in expansion of macro '__fortify_memcpy_chk' > 693 | #define memcpy(p, q, s) __fortify_memcpy_chk(p, q, s, \ > | ^~~~~~~~~~~~~~~~~~~~ > drivers/crypto/atmel-sha.c:1773:9: note: in expansion of macro 'memcpy' > 1773 | memcpy(hmac->opad, hmac->ipad, bs); > | ^~~~~~ > > The same thing happens in two more drivers that have the same logic: > > drivers/crypto/chelsio/chcr_algo.c: In function 'chcr_ahash_setkey': > include/linux/fortify-string.h:57:33: error: '__builtin_memcpy' accessing 129 or more bytes at offsets 260 and 132 overlaps 1 or more bytes at offset 260 [-Werror=restrict] > drivers/crypto/bcm/cipher.c: In function 'ahash_hmac_setkey': > include/linux/fortify-string.h:57:33: error: '__builtin_memcpy' accessing between 129 and 4294967295 bytes at offsets 840 and 712 overlaps between 1 and 4294967167 bytes at offset 840 [-Werror=restrict] > > I don't think it can actually happen because the size is strictly bounded > to the available block sizes, at most 128 bytes, though inlining decisions > could lead gcc to not see that. > > Use the unsafe_memcpy() helper instead of memcpy(), with the only difference > being that this skips the hardening checks that produce the warning. > > Suggested-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> > --- > drivers/crypto/atmel-sha.c | 3 ++- > drivers/crypto/bcm/cipher.c | 3 ++- > drivers/crypto/chelsio/chcr_algo.c | 3 ++- > 3 files changed, 6 insertions(+), 3 deletions(-) Patch applied. Thanks. -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
