linux-kernel - Re: [PATCH 1/2] coda: fix reference counting in coda_file_mmap error path

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Date:   Thu, 22 Apr 2021 10:11:35 +0200
From:   Daniel Vetter <daniel@...ll.ch>
To:     Christian König 
        <ckoenig.leichtzumerken@...il.com>
Cc:     linux-kernel@...r.kernel.org, linux-unionfs@...r.kernel.org,
        codalist@...a.cs.cmu.edu, dri-devel@...ts.freedesktop.org,
        jgg@...pe.ca, jaharkes@...cmu.edu, akpm@...ux-foundation.org,
        miklos@...redi.hu, coda@...cmu.edu
Subject: Re: [PATCH 1/2] coda: fix reference counting in coda_file_mmap error
 path

On Wed, Apr 21, 2021 at 03:20:11PM +0200, Christian König wrote:
> mmap_region() now calls fput() on the vma->vm_file.
> 
> So we need to drop the extra reference on the coda file instead of the
> host file.
> 
> Signed-off-by: Christian König <christian.koenig@....com>
> Fixes: 1527f926fd04 ("mm: mmap: fix fput in error path v2")
> CC: stable@...r.kernel.org # 5.11+

Reviewed-by: Daniel Vetter <daniel.vetter@...ll.ch>

> ---
>  fs/coda/file.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/coda/file.c b/fs/coda/file.c
> index 128d63df5bfb..ef5ca22bfb3e 100644
> --- a/fs/coda/file.c
> +++ b/fs/coda/file.c
> @@ -175,10 +175,10 @@ coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
>  	ret = call_mmap(vma->vm_file, vma);
>  
>  	if (ret) {
> -		/* if call_mmap fails, our caller will put coda_file so we
> -		 * should drop the reference to the host_file that we got.
> +		/* if call_mmap fails, our caller will put host_file so we
> +		 * should drop the reference to the coda_file that we got.
>  		 */
> -		fput(host_file);
> +		fput(coda_file);
>  		kfree(cvm_ops);
>  	} else {
>  		/* here we add redirects for the open/close vm_operations */
> -- 
> 2.25.1
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@...ts.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

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