[PATCH] crypto: lskcipher - propagate errors from unaligned crypt

From: Karl Mehltretter

Date: Sat Aug 08 2026 - 07:50:19 EST


The while loop declares a second err variable that shadows the outer
one. When the crypt callback fails, the goto out path returns the outer
err, which still holds the -ENOMEM value assigned before the successful
allocation check. The real error from the cipher is discarded and the
caller sees -ENOMEM instead.

Drop the inner declaration so the callback error reaches the caller.

Verified with a test module that registers an lskcipher whose encrypt
callback fails with -EIO and calls it through a misaligned buffer.
An unpatched kernel returns -ENOMEM, a patched kernel returns -EIO.

Found with Clang's -Wshadow.

Fixes: 31865c4c4db2b ("crypto: skcipher - Add lskcipher")
Assisted-by: Claude:claude-fable-5
Signed-off-by: Karl Mehltretter <kmehltretter@xxxxxxxxx>
---
crypto/lskcipher.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/crypto/lskcipher.c b/crypto/lskcipher.c
index e4328df6e26c0..a79c9a246e5d7 100644
--- a/crypto/lskcipher.c
+++ b/crypto/lskcipher.c
@@ -95,7 +95,6 @@ static int crypto_lskcipher_crypt_unaligned(

while (len >= bs) {
unsigned chunk = min((unsigned)PAGE_SIZE, len);
- int err;

if (chunk > cs)
chunk &= ~(cs - 1);
--
2.53.0