Hi Xiaoxu,
On Tue, Nov 26, 2019 at 09:38:09PM +0800, Zhang Xiaoxu wrote:
> When set posix acl, it maybe call posix_acl_update_mode in some
> filesystem, eg. ext4. It may set acl to NULL, so, we can't free
> the acl which allocated in posix_acl_xattr_set.
>
> Use an temp value to store the acl address for posix_acl_release.
>
> Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@xxxxxxxxxx>
> ---
> fs/posix_acl.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/fs/posix_acl.c b/fs/posix_acl.c
> index 84ad1c90d535..0a359d06274c 100644
> --- a/fs/posix_acl.c
> +++ b/fs/posix_acl.c
> @@ -882,7 +882,7 @@ posix_acl_xattr_set(const struct xattr_handler *handler,
> const char *name, const void *value,
> size_t size, int flags)
> {
> - struct posix_acl *acl = NULL;
> + struct posix_acl *acl = NULL, *p = NULL;
> int ret;
>
> if (value) {
> @@ -890,8 +890,15 @@ posix_acl_xattr_set(const struct xattr_handler *handler,
> if (IS_ERR(acl))
> return PTR_ERR(acl);
> }
> +
> + /*
> + * when call set_posix_acl, posix_acl_update_mode may set acl
> + * to NULL,use temporary variables p for posix_acl_release.
> + */
> + p = acl;
> ret = set_posix_acl(inode, handler->flags, acl);
IMO, variable acl in this function won't be affected, yes?
Am I missing something?
Thanks,
Gao Xiang
> - posix_acl_release(acl);
> +
> + posix_acl_release(p);
> return ret;
> }
>
> --
> 2.17.2
>
