diff options
| author | Eric Biggers <ebiggers@kernel.org> | 2025-07-06 16:10:58 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-08-28 16:34:14 +0200 |
| commit | ef74efa598b7bbc5c24509f7f56af2806f81c339 (patch) | |
| tree | 2d07edf4b5ada1fb87cee1d9cbaf0d1fffd5ba29 | |
| parent | 87bdfba903be7084cb3ee04032b14a81181fe413 (diff) | |
lib/crypto: arm64/poly1305: Fix register corruption in no-SIMD contexts
commit eec76ea5a7213c48529a46eed1b343e5cee3aaab upstream.
Restore the SIMD usability check that was removed by commit a59e5468a921
("crypto: arm64/poly1305 - Add block-only interface").
This safety check is cheap and is well worth eliminating a footgun.
While the Poly1305 functions should not be called when SIMD registers
are unusable, if they are anyway, they should just do the right thing
instead of corrupting random tasks' registers and/or computing incorrect
MACs. Fixing this is also needed for poly1305_kunit to pass.
Just use may_use_simd() instead of the original crypto_simd_usable(),
since poly1305_kunit won't rely on crypto_simd_disabled_for_test.
Fixes: a59e5468a921 ("crypto: arm64/poly1305 - Add block-only interface")
Cc: stable@vger.kernel.org
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250706231100.176113-4-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/arm64/lib/crypto/poly1305-glue.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm64/lib/crypto/poly1305-glue.c b/arch/arm64/lib/crypto/poly1305-glue.c index c9a74766785b..31aea21ce42f 100644 --- a/arch/arm64/lib/crypto/poly1305-glue.c +++ b/arch/arm64/lib/crypto/poly1305-glue.c @@ -7,6 +7,7 @@ #include <asm/hwcap.h> #include <asm/neon.h> +#include <asm/simd.h> #include <crypto/internal/poly1305.h> #include <linux/cpufeature.h> #include <linux/jump_label.h> @@ -33,7 +34,7 @@ void poly1305_blocks_arch(struct poly1305_block_state *state, const u8 *src, unsigned int len, u32 padbit) { len = round_down(len, POLY1305_BLOCK_SIZE); - if (static_branch_likely(&have_neon)) { + if (static_branch_likely(&have_neon) && likely(may_use_simd())) { do { unsigned int todo = min_t(unsigned int, len, SZ_4K); |