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

[Boris Brezillon]

On Tue, 16 Oct 2018 18:26:34 +0800
Hou Tao  wrote:

> On 2018/10/16 14:41, Richard Weinberger wrote:
> > On Tue, Oct 16, 2018 at 7:53 AM Hou Tao  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: sta...@kernel.org
> >>> Signed-off-by: Hou Tao 
> >>> ---
> >>>  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 
> > 
> > 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
> 
> 
> __
> Linux MTD discussion mailing list
> http://lists.infradead.org/mailman/listinfo/linux-mtd/

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

[Hou Tao]

On 2018/10/16 14:41, Richard Weinberger wrote:
> On Tue, Oct 16, 2018 at 7:53 AM Hou Tao  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: sta...@kernel.org
>>> Signed-off-by: Hou Tao 
>>> ---
>>>  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 
> 
> We can carry this via the MTD tree.
Thanks for that.

Regards,
Tao

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

[Richard Weinberger]

On Tue, Oct 16, 2018 at 7:53 AM Hou Tao  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: sta...@kernel.org
> > Signed-off-by: Hou Tao 
> > ---
> >  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 

We can carry this via the MTD tree.

-- 
Thanks,
//richard

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

[Hou Tao]

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: sta...@kernel.org
> Signed-off-by: Hou Tao 
> ---
>  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;
> - }
>  
>   /* Initialize JFFS2 superblock locks, the further initialization will
>* be done later */
> 

[PATCH] jffs2: free jffs2_sb_info through jffs2_kill_sb()

[Hou Tao]

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: sta...@kernel.org
Signed-off-by: Hou Tao 
---
 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;
-   }
 
/* Initialize JFFS2 superblock locks, the further initialization will
 * be done later */
-- 
2.16.2.dirty