From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A29D876413; Mon, 8 Apr 2024 13:28:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712582909; cv=none; b=tT7W0UlcxFLP+gCU6italyQCd3NPpraWxJ2j/Ox1pZSr4ExoReLFuKAmuF/rQAzIm1MBJq1LVa/IHAxwpWmSXJ6cO4LFFzY3B8gDkzpxGQKsgfO4cP6B55EDVsgDobTxzB6eeiWjAiCf+c9M/RC4phaNuNkF4kMBeqKvPuYmECk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712582909; c=relaxed/simple; bh=KaYlK6hUfQW4bm77aV5salT0dlyLWVobp1V3p1wHBwo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=N0KS60Jc3IDv246m0FoE2EbKhdHOqyLvbYBj0HKpC7WY76zPNY9GddQjf+qd+bCZ6wowcgh38f00bBp36ctaCgGTBF+9ppkuxmQhxQapFyDroauUXVJ54Ir/tmqVuIiCpiA65LrhEHJLdntXvk4jZ2dDehFHBYd55PFkB2Qo2vU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=HDPJ0kmS; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="HDPJ0kmS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 29F13C433C7; Mon, 8 Apr 2024 13:28:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1712582909; bh=KaYlK6hUfQW4bm77aV5salT0dlyLWVobp1V3p1wHBwo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HDPJ0kmS0PCHeosUn1/yyllc1A2C9kYQVBa2hxszIzubSTxjNV22jYh5F1AZ76yxi sAZtH5SH3j1RUYqHLAYvfdooq4w+cBeuC2YwyHDvu0SLI+2XfEuMrT6BVSHy8YeTn/ PwF2FHdSUGNdqdl976pLS0eWFwDJkdejCaxSOHSc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Duoming Zhou , Simon Horman , Jakub Kicinski Subject: [PATCH 6.8 116/273] ax25: fix use-after-free bugs caused by ax25_ds_del_timer Date: Mon, 8 Apr 2024 14:56:31 +0200 Message-ID: <20240408125312.903812770@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240408125309.280181634@linuxfoundation.org> References: <20240408125309.280181634@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Duoming Zhou commit fd819ad3ecf6f3c232a06b27423ce9ed8c20da89 upstream. When the ax25 device is detaching, the ax25_dev_device_down() calls ax25_ds_del_timer() to cleanup the slave_timer. When the timer handler is running, the ax25_ds_del_timer() that calls del_timer() in it will return directly. As a result, the use-after-free bugs could happen, one of the scenarios is shown below: (Thread 1) | (Thread 2) | ax25_ds_timeout() ax25_dev_device_down() | ax25_ds_del_timer() | del_timer() | ax25_dev_put() //FREE | | ax25_dev-> //USE In order to mitigate bugs, when the device is detaching, use timer_shutdown_sync() to stop the timer. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Duoming Zhou Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20240329015023.9223-1-duoming@zju.edu.cn Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/ax25/ax25_dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/ax25/ax25_dev.c +++ b/net/ax25/ax25_dev.c @@ -105,7 +105,7 @@ void ax25_dev_device_down(struct net_dev spin_lock_bh(&ax25_dev_lock); #ifdef CONFIG_AX25_DAMA_SLAVE - ax25_ds_del_timer(ax25_dev); + timer_shutdown_sync(&ax25_dev->dama.slave_timer); #endif /*