linux-kernel - Re: [PATCH] proc: readdir race fix.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 04 Sep 2006 20:54:30 -0600
From:	ebiederm@...ssion.com (Eric W. Biederman)
To:	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
Cc:	linux-kernel@...r.kernel.org, akpm@...l.org,
	saito.tadashi@...t.fujitsu.com, ak@...e.de, oleg@...sign.ru,
	jdelvare@...e.de
Subject: Re: [PATCH] proc: readdir race fix.

KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com> writes:

> On Mon, 04 Sep 2006 17:13:10 -0600
> ebiederm@...ssion.com (Eric W. Biederman) wrote:
> Hi, Hit OOM-Killer, because of memory leak of task struct.
>
> patch is attached.
> -Kame
>
> task struct should be put always.

Good catch. I actually have a pending cleanup that works better if the
task struct is held across the filldir so the incremental patch should look like:

I also noticed a benign typo in TGID_OFFSET (1 subtract one that I shouldn't)

Complete patch in just a moment.

Eric

diff --git a/fs/proc/base.c b/fs/proc/base.c
index b7650b9..03f6680 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2186,7 +2186,7 @@ int proc_pid_readdir(struct file * filp,
        tgid = filp->f_pos - TGID_OFFSET;
        for (task = next_tgid(tgid);
             task;
-            task = next_tgid(tgid + 1)) {
+            put_task_struct(task), task = next_tgid(tgid + 1)) {
                int len;
                ino_t ino;
                tgid = task->pid;

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/