diff mbox series

[v2,1/1] nis: Fix leak on realloc failure in nis_getnames [BZ #28150]

Message ID 20210728182331.1363922-1-rharwood@redhat.com
State Committed
Commit 60698263122b7c54ded3f70a466176e17a529480
Delegated to: Carlos O'Donell
Headers show
Series [v2,1/1] nis: Fix leak on realloc failure in nis_getnames [BZ #28150] | expand

Checks

Context Check Description
dj/TryBot-apply_patch success Patch applied to master at the time it was sent

Commit Message

Robbie Harwood July 28, 2021, 6:23 p.m. UTC
If pos >= count but realloc fails, tmp will not have been placed in
getnames[pos] yet, and so will not be freed in free_null.  Detected
by Coverity.

Also remove misleading comment from nis_getnames(), since it actually
did properly release getnames when out of memory.
---
 nis/nis_subr.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Comments

Carlos O'Donell Aug. 2, 2021, 3:24 p.m. UTC | #1
On 7/28/21 2:23 PM, Robbie Harwood via Libc-alpha wrote:
> If pos >= count but realloc fails, tmp will not have been placed in
> getnames[pos] yet, and so will not be freed in free_null.  Detected
> by Coverity.
> 
> Also remove misleading comment from nis_getnames(), since it actually
> did properly release getnames when out of memory.

The CI/CD patchwork trybot didn't trigger for this patch and I need
to review that with DJ.

I tested on x86_64 and i686 without regression. Florian reviewed.
I'm pushing this fix.

Tested-by: Carlos O'Donell <carlos@redhat.com>

> ---
>  nis/nis_subr.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/nis/nis_subr.c b/nis/nis_subr.c
> index dd0e30071d..6784fc353f 100644
> --- a/nis/nis_subr.c
> +++ b/nis/nis_subr.c
> @@ -103,9 +103,6 @@ count_dots (const_nis_name str)
>    return count;
>  }
>  
> -/* If we run out of memory, we don't give already allocated memory
> -   free. The overhead for bringing getnames back in a safe state to
> -   free it is to big. */
>  nis_name *
>  nis_getnames (const_nis_name name)
>  {
> @@ -271,7 +268,10 @@ nis_getnames (const_nis_name name)
>  	      nis_name *newp = realloc (getnames,
>  					(count + 1) * sizeof (char *));
>  	      if (__glibc_unlikely (newp == NULL))
> -		goto free_null;
> +		{
> +		  free (tmp);
> +		  goto free_null;
> +		}
>  	      getnames = newp;
>  	    }
>  	  getnames[pos] = tmp;
>
diff mbox series

Patch

diff --git a/nis/nis_subr.c b/nis/nis_subr.c
index dd0e30071d..6784fc353f 100644
--- a/nis/nis_subr.c
+++ b/nis/nis_subr.c
@@ -103,9 +103,6 @@  count_dots (const_nis_name str)
   return count;
 }
 
-/* If we run out of memory, we don't give already allocated memory
-   free. The overhead for bringing getnames back in a safe state to
-   free it is to big. */
 nis_name *
 nis_getnames (const_nis_name name)
 {
@@ -271,7 +268,10 @@  nis_getnames (const_nis_name name)
 	      nis_name *newp = realloc (getnames,
 					(count + 1) * sizeof (char *));
 	      if (__glibc_unlikely (newp == NULL))
-		goto free_null;
+		{
+		  free (tmp);
+		  goto free_null;
+		}
 	      getnames = newp;
 	    }
 	  getnames[pos] = tmp;