libvhost-user: Handling potential memory allocation failures

[PATCH] libvhost-user: Handling potential memory allocation failures

Posted by jianchunfu 1 year, 5 months ago

Add malloc check of virtqueue element in libvhost-user.

Signed-off-by: jianchunfu <jianchunfu@cmss.chinamobile.com>
---
 subprojects/libvhost-user/libvhost-user.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/subprojects/libvhost-user/libvhost-user.c b/subprojects/libvhost-user/libvhost-user.c
index 47d2efc60f..901cd7a2c0 100644
--- a/subprojects/libvhost-user/libvhost-user.c
+++ b/subprojects/libvhost-user/libvhost-user.c
@@ -2551,6 +2551,10 @@ virtqueue_alloc_element(size_t sz,
 
     assert(sz >= sizeof(VuVirtqElement));
     elem = malloc(out_sg_end);
+    if (!elem) {
+        DPRINT("%s: failed to malloc virtqelement\n", __func__);
+        exit(0);
+    }
     elem->out_num = out_num;
     elem->in_num = in_num;
     elem->in_sg = (void *)elem + in_sg_ofs;
-- 
2.18.4

Re: [PATCH] libvhost-user: Handling potential memory allocation failures

Posted by Michael S. Tsirkin 1 year, 5 months ago

On Tue, Nov 08, 2022 at 04:01:41PM +0800, jianchunfu wrote:
> Add malloc check of virtqueue element in libvhost-user.
> 
> Signed-off-by: jianchunfu <jianchunfu@cmss.chinamobile.com>
> ---
>  subprojects/libvhost-user/libvhost-user.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/subprojects/libvhost-user/libvhost-user.c b/subprojects/libvhost-user/libvhost-user.c
> index 47d2efc60f..901cd7a2c0 100644
> --- a/subprojects/libvhost-user/libvhost-user.c
> +++ b/subprojects/libvhost-user/libvhost-user.c
> @@ -2551,6 +2551,10 @@ virtqueue_alloc_element(size_t sz,
>  
>      assert(sz >= sizeof(VuVirtqElement));
>      elem = malloc(out_sg_end);
> +    if (!elem) {
> +        DPRINT("%s: failed to malloc virtqelement\n", __func__);
> +        exit(0);
> +    }

exit is certainly not the right way to handle such errors.


>      elem->out_num = out_num;
>      elem->in_num = in_num;
>      elem->in_sg = (void *)elem + in_sg_ofs;
> -- 
> 2.18.4
> 
>

[RFC] libvhost-user: Add report when allocation failures

Posted by jianchunfu 1 year, 5 months ago

Add error report when malloc fails of virtqueue element.
It's a little pointless to return NULL, wouldn't it be right
to report error and exit when malloc fails since it is in a
standalone project while not QEMU.

Signed-off-by: jianchunfu <jianchunfu@cmss.chinamobile.com>
---
 subprojects/libvhost-user/libvhost-user.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/subprojects/libvhost-user/libvhost-user.c b/subprojects/libvhost-user/libvhost-user.c
index 47d2efc60f..c2bdf0fcc1 100644
--- a/subprojects/libvhost-user/libvhost-user.c
+++ b/subprojects/libvhost-user/libvhost-user.c
@@ -2551,6 +2551,10 @@ virtqueue_alloc_element(size_t sz,
 
     assert(sz >= sizeof(VuVirtqElement));
     elem = malloc(out_sg_end);
+    if (!elem) {
+        DPRINT("%s: failed to malloc virtqelement\n", __func__);
+        return NULL;
+    }
     elem->out_num = out_num;
     elem->in_num = in_num;
     elem->in_sg = (void *)elem + in_sg_ofs;
-- 
2.18.4