From: Johannes Berg <johannes@sipsolutions.net>
To: Moon Hee Lee <moonhee.lee.ca@gmail.com>
Cc: linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org,
linux-kernel-mentees@lists.linux.dev, netdev@vger.kernel.org,
syzkaller-bugs@googlegroups.com,
syzbot+d6ccd49ae046542a0641@syzkaller.appspotmail.com,
skhan@linuxfoundation.org, david.hunter.linux@gmail.com
Subject: Re: [PATCH wireless-next] wifi: mac80211: fix use-after-free risk in sta debugfs removal
Date: Thu, 24 Jul 2025 09:18:07 +0200 [thread overview]
Message-ID: <b81013d8f7cccb19ab126aebc7bc442c641d0f4a.camel@sipsolutions.net> (raw)
In-Reply-To: <20250724071555.442634-2-moonhee.lee.ca@gmail.com> (sfid-20250724_091629_457606_AC325110)
On Thu, 2025-07-24 at 00:15 -0700, Moon Hee Lee wrote:
> A NULL pointer dereference may occur in ieee80211_sta_debugfs_remove()
> when debugfs_remove_recursive() is called on a dentry whose inode has
> already been freed. This can happen due to a race between STA teardown
> and debugfs cleanup.
>
> Fix this by checking that both sta->debugfs_dir and its d_inode are
> valid before invoking debugfs_remove_recursive().
>
> This avoids the crash reported in syzbot bug:
Maybe so, but it really looks like a bandaid?! Why are we trying to
remove it twice in the first place?
johannes
next prev parent reply other threads:[~2025-07-24 7:18 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-24 7:15 [PATCH wireless-next] wifi: mac80211: fix use-after-free risk in sta debugfs removal Moon Hee Lee
2025-07-24 7:18 ` Johannes Berg [this message]
2025-07-24 7:48 ` Moon Hee Lee
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