lkml.org 
[lkml]   [2019]   [Sep]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] udf: prevent memory leak in udf_new_inode
On Thu, Sep 26, 2019 at 10:00:31AM +0200, Jan Kara wrote:
> On Wed 25-09-19 23:24:08, Al Viro wrote:
> > On Wed, Sep 25, 2019 at 04:39:03PM -0500, Navid Emamdoost wrote:
> > > In udf_new_inode if either udf_new_block or insert_inode_locked fials
> > > the allocated memory for iinfo->i_ext.i_data should be released.
> >
> > "... because of such-and-such reasons" part appears to be missing.
> > Why should it be released there?
> >
> > > Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
> > > ---
> > > fs/udf/ialloc.c | 2 ++
> > > 1 file changed, 2 insertions(+)
> > >
> > > diff --git a/fs/udf/ialloc.c b/fs/udf/ialloc.c
> > > index 0adb40718a5d..b8ab3acab6b6 100644
> > > --- a/fs/udf/ialloc.c
> > > +++ b/fs/udf/ialloc.c
> > > @@ -86,6 +86,7 @@ struct inode *udf_new_inode(struct inode *dir, umode_t mode)
> > > dinfo->i_location.partitionReferenceNum,
> > > start, &err);
> > > if (err) {
> > > + kfree(iinfo->i_ext.i_data);
> > > iput(inode);
> > > return ERR_PTR(err);
> > > }
> >
> > Have you tested that? Because it has all earmarks of double-free;
> > normal eviction pathway ought to free the damn thing. <greps around
> > a bit>
> >
> > Mind explaining what's to stop ->evict_inode (== udf_evict_inode) from
> > hitting
> > kfree(iinfo->i_ext.i_data);
> > considering that this call of kfree() appears to be unconditional there?
>
> Exactly. udf_evict_inode() is responsible for freeing iinfo->i_ext.i_data
> so the patch would result in double free.
>
> Honza
Thanks for clarification.
> --
> Jan Kara <jack@suse.com>
> SUSE Labs, CR

\
 
 \ /
  Last update: 2019-09-27 05:03    [W:0.026 / U:0.788 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site