Re: [PATCH 3/5] fs: f2fs: initialize fsdata in pagecache_write()

Eric Biggers
2022-11-21T19:54:33Z

On Mon, Nov 21, 2022 at 12:21:32PM +0100, Alexander Potapenko wrote:
> When aops->write_begin() does not initialize fsdata, KMSAN may report
> an error passing the latter to aops->write_end().
>
> Fix this by unconditionally initializing fsdata.
>
> Suggested-by: Eric Biggers <ebiggers@kernel.org>
> Fixes: 95ae251fe828 ("f2fs: add fs-verity support")
> Signed-off-by: Alexander Potapenko <glider@google.com>
> ---
> fs/f2fs/verity.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/f2fs/verity.c b/fs/f2fs/verity.c
> index c352fff88a5e6..3f4f3295f1c66 100644
> --- a/fs/f2fs/verity.c
> +++ b/fs/f2fs/verity.c
> @@ -81,7 +81,7 @@ static int pagecache_write(struct inode *inode, const void *buf, size_t count,
> size_t n = min_t(size_t, count,
> PAGE_SIZE - offset_in_page(pos));
> struct page *page;
> - void *fsdata;
> + void *fsdata = NULL;
> int res;
>
> res = aops->write_begin(NULL, mapping, pos, n, &page, &fsdata);

Reviewed-by: Eric Biggers <ebiggers@google.com>

- Eric