From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Lizhi Xu <lizhi.xu@windriver.com>, Dmitry Vyukov <dvyukov@google.com>
Cc: syzbot+2ff22910687ee0dfd48e@syzkaller.appspotmail.com,
dakr@kernel.org, djrscally@gmail.com, gregkh@linuxfoundation.org,
heikki.krogerus@linux.intel.com, jgg@nvidia.com,
kevin.tian@intel.com, linux-acpi@vger.kernel.org,
linux-kernel@vger.kernel.org, nicolinc@nvidia.com,
rafael@kernel.org, sakari.ailus@linux.intel.com,
syzkaller-bugs@googlegroups.com, yi.l.liu@intel.com
Subject: Re: [PATCH] software node: Prevent link creation failure from causing kobj reference count imbalance
Date: Mon, 14 Apr 2025 09:20:30 +0300 [thread overview]
Message-ID: <Z_ypLhYQwGf41hVK@smile.fi.intel.com> (raw)
In-Reply-To: <20250411004203.2932899-1-lizhi.xu@windriver.com>
On Fri, Apr 11, 2025 at 08:42:02AM +0800, Lizhi Xu wrote:
> syzbot reported a uaf in software_node_notify_remove. [1]
>
> When any of the two sysfs_create_link() in software_node_notify() fails,
> the swnode->kobj reference count will not increase normally, which will
> cause swnode to be released incorrectly due to the imbalance of kobj reference
> count when executing software_node_notify_remove().
>
> Increase the reference count of kobj before creating the link to avoid uaf.
>
> [1]
Please, reduce this to ~5-7 lines only. This is how Submitting Patches document
recommends to put backtraces in the commit messages:
https://www.kernel.org/doc/html/latest/process/submitting-patches.html#backtraces-in-commit-messages
> Fixes: 9eb59204d519 ("iommufd/selftest: Add set_dev_pasid in mock iommu")
> Reported-by: syzbot+2ff22910687ee0dfd48e@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=2ff22910687ee0dfd48e
> Tested-by: syzbot+2ff22910687ee0dfd48e@syzkaller.appspotmail.com
Where is the positive result of it? I can't find the respective log.
To me this one
https://syzkaller.appspot.com/x/report.txt?x=158af070580000
doesn't sound as a useful report as I don't know if this patch fixes one
regression and introduced another.
Dmitry?
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2025-04-14 6:20 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-06 11:37 [syzbot] [acpi?] KASAN: slab-use-after-free Read in software_node_notify_remove syzbot
2025-04-06 13:13 ` Andy Shevchenko
2025-04-06 13:31 ` syzbot
2025-04-06 13:24 ` Andy Shevchenko
2025-04-06 14:09 ` syzbot
2025-04-08 14:54 ` Andy Shevchenko
2025-04-11 0:42 ` [PATCH] software node: Prevent link creation failure from causing kobj reference count imbalance Lizhi Xu
2025-04-14 6:20 ` Andy Shevchenko [this message]
2025-04-14 6:27 ` Andy Shevchenko
2025-04-14 7:08 ` Lizhi Xu
2025-04-14 7:16 ` Andy Shevchenko
2025-04-14 7:11 ` [PATCH V2] " Lizhi Xu
2025-04-14 7:22 ` Andy Shevchenko
2025-04-14 8:41 ` Sakari Ailus
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