[PATCH 6.6 016/160] crypto: caam - fix overflow on long hmac keys

Greg Kroah-Hartman
2026-04-08T18:21:00Z

From: Horia Geantă <horia.geanta@nxp.com>

[ Upstream commit 80688afb9c35b3934ce2d6be9973758915e2e0ef ]

When a key longer than block size is supplied, it is copied and then
hashed into the real key. The memory allocated for the copy needs to
be rounded to DMA cache alignment, as otherwise the hashed key may
corrupt neighbouring memory.

The copying is performed using kmemdup, however this leads to an overflow:
reading more bytes (aligned_len - keylen) from the keylen source buffer.
Fix this by replacing kmemdup with kmalloc, followed by memcpy.

Fixes: 199354d7fb6e ("crypto: caam - Remove GFP_DMA and add DMA alignment padding")
Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/crypto/caam/caamalg_qi2.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/caam/caamalg_qi2.c b/drivers/crypto/caam/caamalg_qi2.c
index a148ff1f0872c..06e0681fdbe15 100644
--- a/drivers/crypto/caam/caamalg_qi2.c
+++ b/drivers/crypto/caam/caamalg_qi2.c
@@ -3325,9 +3325,10 @@ static int ahash_setkey(struct crypto_ahash *ahash, const u8 *key,
if (aligned_len < keylen)
return -EOVERFLOW;

- hashed_key = kmemdup(key, aligned_len, GFP_KERNEL);
+ hashed_key = kmalloc(aligned_len, GFP_KERNEL);
if (!hashed_key)
return -ENOMEM;
+ memcpy(hashed_key, key, keylen);
ret = hash_digest_key(ctx, &keylen, hashed_key, digestsize);
if (ret)
goto bad_free_key;
--
2.53.0