zcomp_create() verifies the success of zcomp_strm_{multi,siggle}_create()
through comp->stream, which can potentially be pointing to memory that was
freed if these functions returned an error.
While at it, replace a 'ERR_PTR(-ENOMEM)' by a more generic
'ERR_PTR(error)' as in the future zcomp_strm_{multi,siggle}_create() could
return other error codes. Function documentation updated accordingly.
Fixes: beca3ec71fe5 ("zram: add multi stream functionality")
Cc: sta...@vger.kernel.org
Cc: Sergey Senozhatsky <sergey.senozhatsky.w...@gmail.com>
Cc: Minchan Kim <minc...@kernel.org>
Signed-off-by: Luis Henriques <luis.henriq...@canonical.com>
---
Changes since v2:
* Renamed local variable 'ret' to 'error'
* Usage of 'ERR_PTR(error)' to accommodate future error codes returned by
zcomp_strm_{multi,siggle}_create
(all suggested by Minchan)
Changes since v1:
* Check zcomp_strm_{multi,siggle}_create() return code instead
comp->stream (suggested by Sergey)
drivers/block/zram/zcomp.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c
index 965d1afb0eaa..5cb13ca3a3ac 100644
--- a/drivers/block/zram/zcomp.c
+++ b/drivers/block/zram/zcomp.c
@@ -330,12 +330,14 @@ void zcomp_destroy(struct zcomp *comp)
* allocate new zcomp and initialize it. return compressing
* backend pointer or ERR_PTR if things went bad. ERR_PTR(-EINVAL)
* if requested algorithm is not supported, ERR_PTR(-ENOMEM) in
- * case of allocation error.
+ * case of allocation error, or any other error potentially
+ * returned by functions zcomp_strm_{multi,single}_create.
*/
struct zcomp *zcomp_create(const char *compress, int max_strm)
{
struct zcomp *comp;
struct zcomp_backend *backend;
+ int error;
backend = find_backend(compress);
if (!backend)
@@ -347,12 +349,12 @@ struct zcomp *zcomp_create(const char *compress, int
max_strm)
comp->backend = backend;
if (max_strm > 1)
- zcomp_strm_multi_create(comp, max_strm);
+ error = zcomp_strm_multi_create(comp, max_strm);
else
- zcomp_strm_single_create(comp);
- if (!comp->stream) {
+ error = zcomp_strm_single_create(comp);
+ if (error) {
kfree(comp);
- return ERR_PTR(-ENOMEM);
+ return ERR_PTR(error);
}
return comp;
}
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
