* [PATCH] udf: prevent memory leak in udf_new_inode
@ 2019-09-25 21:39 Navid Emamdoost
2019-09-25 22:24 ` Al Viro
0 siblings, 1 reply; 4+ messages in thread
From: Navid Emamdoost @ 2019-09-25 21:39 UTC (permalink / raw)
Cc: emamd001, kjlu, smccaman, Navid Emamdoost, Jan Kara, linux-kernel
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.
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);
}
@@ -130,6 +131,7 @@ struct inode *udf_new_inode(struct inode *dir, umode_t mode)
inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
iinfo->i_crtime = inode->i_mtime;
if (unlikely(insert_inode_locked(inode) < 0)) {
+ kfree(iinfo->i_ext.i_data);
make_bad_inode(inode);
iput(inode);
return ERR_PTR(-EIO);
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] udf: prevent memory leak in udf_new_inode
2019-09-25 21:39 [PATCH] udf: prevent memory leak in udf_new_inode Navid Emamdoost
@ 2019-09-25 22:24 ` Al Viro
2019-09-26 8:00 ` Jan Kara
0 siblings, 1 reply; 4+ messages in thread
From: Al Viro @ 2019-09-25 22:24 UTC (permalink / raw)
To: Navid Emamdoost; +Cc: emamd001, kjlu, smccaman, Jan Kara, linux-kernel
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?
> @@ -130,6 +131,7 @@ struct inode *udf_new_inode(struct inode *dir, umode_t mode)
> inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
> iinfo->i_crtime = inode->i_mtime;
> if (unlikely(insert_inode_locked(inode) < 0)) {
> + kfree(iinfo->i_ext.i_data);
> make_bad_inode(inode);
> iput(inode);
> return ERR_PTR(-EIO);
And the same here.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] udf: prevent memory leak in udf_new_inode
2019-09-25 22:24 ` Al Viro
@ 2019-09-26 8:00 ` Jan Kara
2019-09-27 3:02 ` Navid Emamdoost
0 siblings, 1 reply; 4+ messages in thread
From: Jan Kara @ 2019-09-26 8:00 UTC (permalink / raw)
To: Al Viro; +Cc: Navid Emamdoost, Jan Kara, emamd001, kjlu, smccaman, linux-kernel
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
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] udf: prevent memory leak in udf_new_inode
2019-09-26 8:00 ` Jan Kara
@ 2019-09-27 3:02 ` Navid Emamdoost
0 siblings, 0 replies; 4+ messages in thread
From: Navid Emamdoost @ 2019-09-27 3:02 UTC (permalink / raw)
To: Jan Kara; +Cc: Al Viro, Jan Kara, emamd001, kjlu, smccaman, linux-kernel
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
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-09-27 3:02 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2019-09-25 21:39 [PATCH] udf: prevent memory leak in udf_new_inode Navid Emamdoost
2019-09-25 22:24 ` Al Viro
2019-09-26 8:00 ` Jan Kara
2019-09-27 3:02 ` Navid Emamdoost
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