Re: [PATCH] jffs2: free jffs2_sb_info through jffs2_kill_sb()

[Boris Brezillon]

On Tue, 16 Oct 2018 18:26:34 +0800
Hou Tao <houtao1@xxxxxxxxxx> wrote:

> On 2018/10/16 14:41, Richard Weinberger wrote:
> > On Tue, Oct 16, 2018 at 7:53 AM Hou Tao <houtao1@xxxxxxxxxx> wrote:  
> >>
> >> ping ?
> >>
> >> On 2018/10/6 17:09, Hou Tao wrote:  
> >>> When an invalid mount option is passed to jffs2, jffs2_parse_options()
> >>> will fail and jffs2_sb_info will be freed, but then jffs2_sb_info will
> >>> be used (use-after-free) and freeed (double-free) in jffs2_kill_sb().
> >>>
> >>> Fix it by removing the buggy invocation of kfree() when getting invalid
> >>> mount options.
> >>>
> >>> Cc: stable@xxxxxxxxxx
> >>> Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
> >>> ---
> >>>  fs/jffs2/super.c | 4 +---
> >>>  1 file changed, 1 insertion(+), 3 deletions(-)
> >>>
> >>> diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
> >>> index 87bdf0f4cba1..902a7dd10e5c 100644
> >>> --- a/fs/jffs2/super.c
> >>> +++ b/fs/jffs2/super.c
> >>> @@ -285,10 +285,8 @@ static int jffs2_fill_super(struct super_block *sb, void *data, int silent)
> >>>       sb->s_fs_info = c;
> >>>
> >>>       ret = jffs2_parse_options(c, data);
> >>> -     if (ret) {
> >>> -             kfree(c);
> >>> +     if (ret)
> >>>               return -EINVAL;
> >>> -     }  
> > 
> > Reviewed-by: Richard Weinberger <richard@xxxxxx>
> > 
> > We can carry this via the MTD tree.  
> Thanks for that.

Applied after adding

Fixes: 92abc475d8de ("jffs2: implement mount option parsing and compression overriding")

> 
> Regards,
> Tao
> 
> 
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