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| author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2016-09-13 09:48:53 +0100 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2016-09-13 18:44:59 +0800 |
| commit | 2db34e78f126c6001d79d3b66ab1abb482dc7caa (patch) | |
| tree | 072fdeb208b2b697d729308bbaf1f5851b555188 /arch/arm64 | |
| parent | f82e90b28654804ab72881d577d87c3d5c65e2bc (diff) | |
| download | linux-2db34e78f126c6001d79d3b66ab1abb482dc7caa.tar.gz linux-2db34e78f126c6001d79d3b66ab1abb482dc7caa.tar.bz2 linux-2db34e78f126c6001d79d3b66ab1abb482dc7caa.zip | |
crypto: arm64/aes-ctr - fix NULL dereference in tail processing
The AES-CTR glue code avoids calling into the blkcipher API for the
tail portion of the walk, by comparing the remainder of walk.nbytes
modulo AES_BLOCK_SIZE with the residual nbytes, and jumping straight
into the tail processing block if they are equal. This tail processing
block checks whether nbytes != 0, and does nothing otherwise.
However, in case of an allocation failure in the blkcipher layer, we
may enter this code with walk.nbytes == 0, while nbytes > 0. In this
case, we should not dereference the source and destination pointers,
since they may be NULL. So instead of checking for nbytes != 0, check
for (walk.nbytes % AES_BLOCK_SIZE) != 0, which implies the former in
non-error conditions.
Fixes: 49788fe2a128 ("arm64/crypto: AES-ECB/CBC/CTR/XTS using ARMv8 NEON and Crypto Extensions")
Cc: stable@vger.kernel.org
Reported-by: xiakaixu <xiakaixu@huawei.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/crypto/aes-glue.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm64/crypto/aes-glue.c b/arch/arm64/crypto/aes-glue.c index 5c888049d061..6b2aa0fd6cd0 100644 --- a/arch/arm64/crypto/aes-glue.c +++ b/arch/arm64/crypto/aes-glue.c @@ -216,7 +216,7 @@ static int ctr_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst, err = blkcipher_walk_done(desc, &walk, walk.nbytes % AES_BLOCK_SIZE); } - if (nbytes) { + if (walk.nbytes % AES_BLOCK_SIZE) { u8 *tdst = walk.dst.virt.addr + blocks * AES_BLOCK_SIZE; u8 *tsrc = walk.src.virt.addr + blocks * AES_BLOCK_SIZE; u8 __aligned(8) tail[AES_BLOCK_SIZE]; |