Re: [PATCH v2] ocxl: Fix potential memory leak on context creation
From: Greg Kurz <hidden>
Date: 2019-05-20 09:12:50
On Mon, 20 May 2019 09:16:18 +0200 Frederic Barrat [off-list ref] wrote:
If we couldn't fully init a context, we were leaking memory.
Fixes: b9721d275cc2 ("ocxl: Allow external drivers to use OpenCAPI contexts")Oops... missed that during review :-\
Signed-off-by: Frederic Barrat <redacted> --- Changelog: v2: reset context pointer in case of allocation failure (Andrew)
Alternatively you could change the code to do:
ctx = kzalloc(sizeof(struct ocxl_context), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
.
.
.
if (pasid < 0) {
mutex_unlock(&afu->contexts_lock);
kfree(ctx);
return pasid;
}
.
.
.
*context = ctx;
return 0;
}
This has the advantage of clearing any risk of side-effect with
*context forever, which is a safer practice IMHO.
Patch is correct anyway, so:
Reviewed-by: Greg Kurz <redacted>
quoted hunk ↗ jump to hunk
drivers/misc/ocxl/context.c | 2 ++ 1 file changed, 2 insertions(+)diff --git a/drivers/misc/ocxl/context.c b/drivers/misc/ocxl/context.c index bab9c9364184..24e4fb010275 100644 --- a/drivers/misc/ocxl/context.c +++ b/drivers/misc/ocxl/context.c@@ -22,6 +22,8 @@ int ocxl_context_alloc(struct ocxl_context **context, struct ocxl_afu *afu, afu->pasid_base + afu->pasid_max, GFP_KERNEL); if (pasid < 0) { mutex_unlock(&afu->contexts_lock); + kfree(*context); + *context = NULL; return pasid; } afu->pasid_count++;