2010-08-11 10:11:45

by Julia Lawall

Subject: [PATCH 4/5] fs/ecryptfs: Return -ENOMEM on memory allocation failure

From: Julia Lawall <[email protected]>

In this code, 0 is returned on memory allocation failure, even though other
failures return -ENOMEM or other similar values.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
expression ret;
expression x,e1,e2,e3;
@@

ret = 0
... when != ret = e1
*x = \(kmalloc\|kcalloc\|kzalloc\)(...)
... when != ret = e2
if (x == NULL) { ... when != ret = e3
return ret;
}
// </smpl>

Signed-off-by: Julia Lawall <[email protected]>

---
fs/ecryptfs/keystore.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
index 89c5476..73811cf 100644
--- a/fs/ecryptfs/keystore.c
+++ b/fs/ecryptfs/keystore.c
@@ -515,6 +515,7 @@ ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes,
if (!s) {
printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc "
"[%zd] bytes of kernel memory\n", __func__, sizeof(*s));
+ rc = -ENOMEM;
goto out;
}
s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
@@ -806,6 +807,7 @@ ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size,
if (!s) {
printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc "
"[%zd] bytes of kernel memory\n", __func__, sizeof(*s));
+ rc = -ENOMEM;
goto out;
}
s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;

2010-08-12 14:55:01

by Tyler Hicks

Subject: Re: [PATCH 4/5] fs/ecryptfs: Return -ENOMEM on memory allocation failure

Thanks Julia - Applied to
git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs/ecryptfs-2.6.git#next

Tyler

On Wed Aug 11, 2010 at 12:11:41PM +0200, Julia Lawall <[email protected]> wrote:
> From: Julia Lawall <[email protected]>
>
> In this code, 0 is returned on memory allocation failure, even though other
> failures return -ENOMEM or other similar values.
>
> A simplified version of the semantic match that finds this problem is as
> follows: (http://coccinelle.lip6.fr/)
>
> // <smpl>
> @@
> expression ret;
> expression x,e1,e2,e3;
> @@
>
> ret = 0
> ... when != ret = e1
> *x = \(kmalloc\|kcalloc\|kzalloc\)(...)
> ... when != ret = e2
> if (x == NULL) { ... when != ret = e3
> return ret;
> }
> // </smpl>
>
> Signed-off-by: Julia Lawall <[email protected]>
>
> ---
> fs/ecryptfs/keystore.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
> index 89c5476..73811cf 100644
> --- a/fs/ecryptfs/keystore.c
> +++ b/fs/ecryptfs/keystore.c
> @@ -515,6 +515,7 @@ ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes,
> if (!s) {
> printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc "
> "[%zd] bytes of kernel memory\n", __func__, sizeof(*s));
> + rc = -ENOMEM;
> goto out;
> }
> s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
> @@ -806,6 +807,7 @@ ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size,
> if (!s) {
> printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc "
> "[%zd] bytes of kernel memory\n", __func__, sizeof(*s));
> + rc = -ENOMEM;
> goto out;
> }
> s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;