[PATCH v2] ecryptfs: replace BUG_ON with error handling code

[PATCH v2] ecryptfs: replace BUG_ON with error handling code

[Aditya Pakki]

In crypt_scatterlist, if the crypt_stat argument is not set up
correctly, the kernel crashes. Instead, by returning an error code
upstream, the error is handled safely.

The issue is detected via a static analysis tool written by us.

Fixes: 237fead619984 (ecryptfs: fs/Makefile and fs/Kconfig)
Signed-off-by: Aditya Pakki <pakki001@umn.edu>
---
v1: Add missing fixes tag suggested by Markus and Tyler.
---
 fs/ecryptfs/crypto.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index db1ef144c63a..2c449aed1b92 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -311,8 +311,10 @@ static int crypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat,
 	struct extent_crypt_result ecr;
 	int rc = 0;
 
-	BUG_ON(!crypt_stat || !crypt_stat->tfm
-	       || !(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED));
+	if (!crypt_stat || !crypt_stat->tfm
+	       || !(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
+		return -EINVAL;
+
 	if (unlikely(ecryptfs_verbosity > 0)) {
 		ecryptfs_printk(KERN_DEBUG, "Key size [%zd]; key:\n",
 				crypt_stat->key_size);
-- 
2.20.1

Re: [PATCH v2] ecryptfs: replace BUG_ON with error handling code

[Tyler Hicks]

On 2020-02-14 12:21:01, Aditya Pakki wrote:
> In crypt_scatterlist, if the crypt_stat argument is not set up
> correctly, the kernel crashes. Instead, by returning an error code
> upstream, the error is handled safely.
> 
> The issue is detected via a static analysis tool written by us.
> 
> Fixes: 237fead619984 (ecryptfs: fs/Makefile and fs/Kconfig)
> Signed-off-by: Aditya Pakki <pakki001@umn.edu>

Thanks! This looks good to me and passes the eCryptfs regression tests.
I've queued it up in my tree.

Tyler

> ---
> v1: Add missing fixes tag suggested by Markus and Tyler.
> ---
>  fs/ecryptfs/crypto.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
> index db1ef144c63a..2c449aed1b92 100644
> --- a/fs/ecryptfs/crypto.c
> +++ b/fs/ecryptfs/crypto.c
> @@ -311,8 +311,10 @@ static int crypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat,
>  	struct extent_crypt_result ecr;
>  	int rc = 0;
>  
> -	BUG_ON(!crypt_stat || !crypt_stat->tfm
> -	       || !(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED));
> +	if (!crypt_stat || !crypt_stat->tfm
> +	       || !(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
> +		return -EINVAL;
> +
>  	if (unlikely(ecryptfs_verbosity > 0)) {
>  		ecryptfs_printk(KERN_DEBUG, "Key size [%zd]; key:\n",
>  				crypt_stat->key_size);
> -- 
> 2.20.1
>