From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Linux trace kernel <linux-trace-kernel@vger.kernel.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Mark Rutland <mark.rutland@arm.com>
Subject: Re: [PATCH] eventfs: Test for dentries array allocated in eventfs_release()
Date: Sun, 1 Oct 2023 00:12:53 +0900 [thread overview]
Message-ID: <20231001001253.19971f4357e85d372ef34fc2@kernel.org> (raw)
In-Reply-To: <20230930090106.1c3164e9@rorschach.local.home>
On Sat, 30 Sep 2023 09:01:06 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:
> From: "Steven Rostedt (Google)" <rostedt@goodmis.org>
>
> The dcache_dir_open_wrapper() could be called when a dynamic event is
> being deleted leaving a dentry with no children. In this case the
> dlist->dentries array will never be allocated. This needs to be checked
> for in eventfs_release(), otherwise it will trigger a NULL pointer
> dereference.
Looks good to me.
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Thank you,
>
> Fixes: ef36b4f92868 ("eventfs: Remember what dentries were created on dir open")
> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
> ---
> fs/tracefs/event_inode.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c
> index 5f1714089884..8c8d64e76103 100644
> --- a/fs/tracefs/event_inode.c
> +++ b/fs/tracefs/event_inode.c
> @@ -421,7 +421,7 @@ static int eventfs_release(struct inode *inode, struct file *file)
> if (WARN_ON_ONCE(!dlist))
> return -EINVAL;
>
> - for (i = 0; dlist->dentries[i]; i++) {
> + for (i = 0; dlist->dentries && dlist->dentries[i]; i++) {
> dput(dlist->dentries[i]);
> }
>
> --
> 2.40.1
>
--
Masami Hiramatsu (Google) <mhiramat@kernel.org>
prev parent reply other threads:[~2023-09-30 15:13 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-30 13:01 [PATCH] eventfs: Test for dentries array allocated in eventfs_release() Steven Rostedt
2023-09-30 15:12 ` Masami Hiramatsu [this message]
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