From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
To: Roman Gushchin <roman.gushchin@linux.dev>,
Andrew Morton <akpm@linux-foundation.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH] mm: shrinkers: fix double kfree on shrinker name
Date: Wed, 20 Jul 2022 23:47:55 +0900 [thread overview]
Message-ID: <ffa62ece-6a42-2644-16cf-0d33ef32c676@I-love.SAKURA.ne.jp> (raw)
syzbot is reporting double kfree() at free_prealloced_shrinker() [1], for
destroy_unused_super() calls free_prealloced_shrinker() even if
prealloc_shrinker() returned an error. Explicitly clear shrinker name
when prealloc_shrinker() called kfree().
Link: https://syzkaller.appspot.com/bug?extid=8b481578352d4637f510 [1]
Reported-by: syzbot <syzbot+8b481578352d4637f510@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: e33c267ab70de424 ("mm: shrinkers: provide shrinkers with names")
---
mm/vmscan.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 64ffdcd019a9..3302d9ed332e 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -707,8 +707,10 @@ int register_shrinker(struct shrinker *shrinker, const char *fmt, ...)
return -ENOMEM;
err = __register_shrinker(shrinker);
- if (err)
+ if (err) {
kfree_const(shrinker->name);
+ shrinker->name = NULL;
+ }
return err;
}
#else
--
2.18.4
next reply other threads:[~2022-07-20 14:48 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-20 14:47 Tetsuo Handa [this message]
2022-07-20 16:29 ` [PATCH] mm: shrinkers: fix double kfree on shrinker name Roman Gushchin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=ffa62ece-6a42-2644-16cf-0d33ef32c676@I-love.SAKURA.ne.jp \
--to=penguin-kernel@i-love.sakura.ne.jp \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=roman.gushchin@linux.dev \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).