Re: [PATCH v2] smb: client: fix possible double free in smb2_set_ea()

[Steve French]

merged into cifs-2.6.git for-next pending additional testing

On Tue, Oct 15, 2024 at 5:45 AM Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
>
> On Tue, Oct 15, 2024 at 06:20:37PM +0800, Su Hui wrote:
> > Clang static checker(scan-build) warning：
> > fs/smb/client/smb2ops.c:1304:2: Attempt to free released memory.
> >  1304 |         kfree(ea);
> >       |         ^~~~~~~~~
> >
> > There is a double free in such case:
> > 'ea is initialized to NULL' -> 'first successful memory allocation for
> > ea' -> 'something failed, goto sea_exit' -> 'first memory release for ea'
> > -> 'goto replay_again' -> 'second goto sea_exit before allocate memory
> > for ea' -> 'second memory release for ea resulted in double free'.
> >
> > Re-initialie 'ea' to NULL near to the replay_again label, it can fix this
> > double free problem.
> >
> > Fixes: 4f1fffa23769 ("cifs: commands that are retried should have replay flag set")
> > Signed-off-by: Su Hui <suhui@xxxxxxxxxxxx>
> > ---
> > v2:
> > - Move 'ea = NULL' near to the replay_again label.(Dan's suggestion)
>
> Thanks!
>
> Reviewed-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
>
> regards,
> dan carpenter
>
>


-- 
Thanks,

Steve