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 7D20318C003; Tue, 10 Sep 2024 10:27:21 +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=1725964041; cv=none; b=kQh0wyW5S0qJEYAA4hYMewljcuaYuYCIQhbleJiVPWAJ42z6aPSmfvw2uugP7Gvn+kwwRMG7U2rVUX7RA8gfsM1DzPTRIUqLv5vatZtng3ll1xoT+veE5kr8lasaJkXJrYjWvY+2N1LSR/AGghQzk/uy3a2FClf1o5EdaZKP9vA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725964041; c=relaxed/simple; bh=eoNo7AZtGJYU5ksIqKiFekhAInnClN4/rdb43FRZaEk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kdCHdTh+W1HLbx7hHtVQmsBK3qNV6cIWt/Djv6ACyQunD7esI+b8tyhRxdW6p7D3mTnstgnG6HUjjGzlsIuW0sp0pDWCv+OuIhgm1dbS+AL3FxLqMXqp4p4WwVd5Fc4M11yGFghIPQItWviT3IGsXZ6caS0mSHteWx4JUFoX/2k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=lxc1WHVN; 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="lxc1WHVN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9D8CAC4CEC3; Tue, 10 Sep 2024 10:27:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1725964041; bh=eoNo7AZtGJYU5ksIqKiFekhAInnClN4/rdb43FRZaEk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lxc1WHVNzr6vO7W52BVxQFbTjaqjMd1mRz5DMatkCVBRRrunxhB/7s2Xap3dlzGyV GfK0UK4pi2N/RpEHhAGLxI7BYvQVCep8eR2EHoqpsJrxEvGJYopN24D4yPzujcGNet 9Pr5TlzEaQ9i/CyI35C4tbdze8hhOt9u4Ta0IE04= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable@kernel.org, Baokun Li , David Howells , Christian Brauner Subject: [PATCH 6.6 047/269] fscache: delete fscache_cookie_lru_timer when fscache exits to avoid UAF Date: Tue, 10 Sep 2024 11:30:34 +0200 Message-ID: <20240910092609.929071860@linuxfoundation.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240910092608.225137854@linuxfoundation.org> References: <20240910092608.225137854@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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Baokun Li commit 72a6e22c604c95ddb3b10b5d3bb85b6ff4dbc34f upstream. The fscache_cookie_lru_timer is initialized when the fscache module is inserted, but is not deleted when the fscache module is removed. If timer_reduce() is called before removing the fscache module, the fscache_cookie_lru_timer will be added to the timer list of the current cpu. Afterwards, a use-after-free will be triggered in the softIRQ after removing the fscache module, as follows: ================================================================== BUG: unable to handle page fault for address: fffffbfff803c9e9 PF: supervisor read access in kernel mode PF: error_code(0x0000) - not-present page PGD 21ffea067 P4D 21ffea067 PUD 21ffe6067 PMD 110a7c067 PTE 0 Oops: Oops: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G W 6.11.0-rc3 #855 Tainted: [W]=WARN RIP: 0010:__run_timer_base.part.0+0x254/0x8a0 Call Trace: tmigr_handle_remote_up+0x627/0x810 __walk_groups.isra.0+0x47/0x140 tmigr_handle_remote+0x1fa/0x2f0 handle_softirqs+0x180/0x590 irq_exit_rcu+0x84/0xb0 sysvec_apic_timer_interrupt+0x6e/0x90 asm_sysvec_apic_timer_interrupt+0x1a/0x20 RIP: 0010:default_idle+0xf/0x20 default_idle_call+0x38/0x60 do_idle+0x2b5/0x300 cpu_startup_entry+0x54/0x60 start_secondary+0x20d/0x280 common_startup_64+0x13e/0x148 Modules linked in: [last unloaded: netfs] ================================================================== Therefore delete fscache_cookie_lru_timer when removing the fscahe module. Fixes: 12bb21a29c19 ("fscache: Implement cookie user counting and resource pinning") Cc: stable@kernel.org Signed-off-by: Baokun Li Link: https://lore.kernel.org/r/20240826112056.2458299-1-libaokun@huaweicloud.com Acked-by: David Howells Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman --- fs/fscache/main.c | 1 + 1 file changed, 1 insertion(+) --- a/fs/fscache/main.c +++ b/fs/fscache/main.c @@ -114,6 +114,7 @@ static void __exit fscache_exit(void) kmem_cache_destroy(fscache_cookie_jar); fscache_proc_cleanup(); + timer_shutdown_sync(&fscache_cookie_lru_timer); destroy_workqueue(fscache_wq); pr_notice("Unloaded\n"); }