From: Al Viro <viro@zeniv.linux.org.uk>
To: Navid Emamdoost <navid.emamdoost@gmail.com>
Cc: emamd001@umn.edu, kjlu@umn.edu, smccaman@umn.edu,
Jan Kara <jack@suse.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] udf: prevent memory leak in udf_new_inode
Date: Wed, 25 Sep 2019 23:24:08 +0100 [thread overview]
Message-ID: <20190925222408.GN26530@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20190925213904.12128-1-navid.emamdoost@gmail.com>
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.
next prev parent reply other threads:[~2019-09-25 22:24 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-25 21:39 [PATCH] udf: prevent memory leak in udf_new_inode Navid Emamdoost
2019-09-25 22:24 ` Al Viro [this message]
2019-09-26 8:00 ` Jan Kara
2019-09-27 3:02 ` Navid Emamdoost
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