From: David Sterba <dsterba@suse.cz>
To: Colin Ian King <colin.king@canonical.com>
Cc: dsterba@suse.cz, Chris Mason <clm@fb.com>,
Josef Bacik <josef@toxicpanda.com>,
David Sterba <dsterba@suse.com>,
linux-btrfs@vger.kernel.org, kernel-janitors@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH][next] btrfs: fix memory leak of path on error return path
Date: Thu, 4 Jul 2019 19:20:07 +0200 [thread overview]
Message-ID: <20190704172007.GB20977@twin.jikos.cz> (raw)
In-Reply-To: <366d87f9-96ea-ecc3-6464-9d20e3050248@canonical.com>
On Thu, Jul 04, 2019 at 05:47:50PM +0100, Colin Ian King wrote:
> >> tmp_ulist = ulist_alloc(GFP_KERNEL);
> >> if (!roots || !tmp_ulist) {
> >> ret = -ENOMEM;
> >> + btrfs_free_path(path);
> >
> > This fixes only one leak, therere are more that I spotted while
> > reviewing this patch. The gotos from the while-loop jump to
> > out_free_list but that leave the path behind>
> > That's why the exit block is a better place for the cleanups. This
> > requires proper nesting of the cleanup calls, that's slightly
> > inconvenient in this case. The free_path is before call to
> > unlock_extent_cached so when the ordre is switched and free_path moved
> > to out_free_ulist, then all the leaks are addressed in one go.
>
> Oh, yes. Even static analysis missed that too!
>
> > Bummer that the leaks escaped sight of original patch author (me), 2
> > reviewers and now 1 fix reviewer.
> >
> Given that you can see more issues, I'll leave the fix in your capable
> hands.
This
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -4764,11 +4764,11 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
ret = emit_last_fiemap_cache(fieinfo, &cache);
free_extent_map(em);
out:
- btrfs_free_path(path);
unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len - 1,
&cached_state);
out_free_ulist:
+ btrfs_free_path(path);
ulist_free(roots);
ulist_free(tmp_ulist);
return ret;
---
should fix it.
next prev parent reply other threads:[~2019-07-04 17:19 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-02 14:10 [PATCH][next] btrfs: fix memory leak of path on error return path Colin King
2019-07-04 16:37 ` David Sterba
2019-07-04 16:47 ` Colin Ian King
2019-07-04 17:20 ` David Sterba [this message]
2019-07-05 1:28 ` Anand Jain
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