[PATCH] crypto: iaa - Fix out-of-bounds index in find_empty_iaa_compression_mode

[PATCH] crypto: iaa - Fix out-of-bounds index in find_empty_iaa_compression_mode

[Thorsten Blum]

The local variable 'i' is initialized with -EINVAL, but the for loop
immediately overwrites it and -EINVAL is never returned.

If no empty compression mode can be found, the function would return the
out-of-bounds index IAA_COMP_MODES_MAX, which would cause an invalid
array access in add_iaa_compression_mode().

Fix both issues by returning either a valid index or -EINVAL.

Cc: stable@vger.kernel.org
Fixes: b190447e0fa3 ("crypto: iaa - Add compression mode management along with fixed mode")
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
 drivers/crypto/intel/iaa/iaa_crypto_main.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/crypto/intel/iaa/iaa_crypto_main.c b/drivers/crypto/intel/iaa/iaa_crypto_main.c
index 23f585219fb4..8ee2a55ec449 100644
--- a/drivers/crypto/intel/iaa/iaa_crypto_main.c
+++ b/drivers/crypto/intel/iaa/iaa_crypto_main.c
@@ -221,15 +221,13 @@ static struct iaa_compression_mode *iaa_compression_modes[IAA_COMP_MODES_MAX];
 
 static int find_empty_iaa_compression_mode(void)
 {
-	int i = -EINVAL;
+	int i;
 
-	for (i = 0; i < IAA_COMP_MODES_MAX; i++) {
-		if (iaa_compression_modes[i])
-			continue;
-		break;
-	}
+	for (i = 0; i < IAA_COMP_MODES_MAX; i++)
+		if (!iaa_compression_modes[i])
+			return i;
 
-	return i;
+	return -EINVAL;
 }
 
 static struct iaa_compression_mode *find_iaa_compression_mode(const char *name, int *idx)
-- 
Thorsten Blum <thorsten.blum@linux.dev>
GPG: 1D60 735E 8AEF 3BE4 73B6  9D84 7336 78FD 8DFE EAD4

RE: [PATCH] crypto: iaa - Fix out-of-bounds index in find_empty_iaa_compression_mode

[Sridhar, Kanchana P]

> -----Original Message-----
> From: Thorsten Blum <thorsten.blum@linux.dev>
> Sent: Thursday, November 27, 2025 6:02 AM
> To: Accardi, Kristen C <kristen.c.accardi@intel.com>; Gomes, Vinicius
> <vinicius.gomes@intel.com>; Sridhar, Kanchana P
> <kanchana.p.sridhar@intel.com>; Herbert Xu
> <herbert@gondor.apana.org.au>; David S. Miller <davem@davemloft.net>;
> Tom Zanussi <tom.zanussi@linux.intel.com>
> Cc: Thorsten Blum <thorsten.blum@linux.dev>; stable@vger.kernel.org;
> linux-crypto@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: [PATCH] crypto: iaa - Fix out-of-bounds index in
> find_empty_iaa_compression_mode
> 
> The local variable 'i' is initialized with -EINVAL, but the for loop
> immediately overwrites it and -EINVAL is never returned.
> 
> If no empty compression mode can be found, the function would return the
> out-of-bounds index IAA_COMP_MODES_MAX, which would cause an invalid
> array access in add_iaa_compression_mode().
> 
> Fix both issues by returning either a valid index or -EINVAL.
> 
> Cc: stable@vger.kernel.org
> Fixes: b190447e0fa3 ("crypto: iaa - Add compression mode management
> along with fixed mode")
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>

Acked-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>


> ---
>  drivers/crypto/intel/iaa/iaa_crypto_main.c | 12 +++++-------
>  1 file changed, 5 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/crypto/intel/iaa/iaa_crypto_main.c
> b/drivers/crypto/intel/iaa/iaa_crypto_main.c
> index 23f585219fb4..8ee2a55ec449 100644
> --- a/drivers/crypto/intel/iaa/iaa_crypto_main.c
> +++ b/drivers/crypto/intel/iaa/iaa_crypto_main.c
> @@ -221,15 +221,13 @@ static struct iaa_compression_mode
> *iaa_compression_modes[IAA_COMP_MODES_MAX];
> 
>  static int find_empty_iaa_compression_mode(void)
>  {
> -	int i = -EINVAL;
> +	int i;
> 
> -	for (i = 0; i < IAA_COMP_MODES_MAX; i++) {
> -		if (iaa_compression_modes[i])
> -			continue;
> -		break;
> -	}
> +	for (i = 0; i < IAA_COMP_MODES_MAX; i++)
> +		if (!iaa_compression_modes[i])
> +			return i;
> 
> -	return i;
> +	return -EINVAL;
>  }
> 
>  static struct iaa_compression_mode *find_iaa_compression_mode(const
> char *name, int *idx)
> --
> Thorsten Blum <thorsten.blum@linux.dev>
> GPG: 1D60 735E 8AEF 3BE4 73B6  9D84 7336 78FD 8DFE EAD4