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 3E835191466; Tue, 10 Sep 2024 09:43:55 +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=1725961435; cv=none; b=c7bnyxr5Mlp/zULApoznZuL5Uck8G9LznUKCXxOL+xI4RxcOaNtfyRnGLYFqMUombSzyQ3nO1tqfIXtA8ckWiFW9+sS75AId0iTcI12JxIvsjsCzZ5QWH7LZlOFmT6TaGH9UIVP0TCCCxkurTQ3cjx+XY3YV2LHV6+Lxq2KlHJg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725961435; c=relaxed/simple; bh=2HE8F5Tqbq4u/nwny2GAFND5QFbqgdrxaFU/1LR2+5E=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FsOSRBPk69JaPu6FFMyYKj2nMA6q2BJ9+ITO6GlNE+9KEy/hNH53Z0e+pFqzbiIUzHYt49lWzX9BU6tq7asFWGmN7I4kE1y+bTsU3pakVuw3EI9poDmE+tWzcGC3Dn9u8b0BgLMbtccvYzRaNC6fFDmRGjWoDFqdbMGT/GmGCog= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=rEQNF9ui; 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="rEQNF9ui" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BBDB4C4CEC3; Tue, 10 Sep 2024 09:43:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1725961435; bh=2HE8F5Tqbq4u/nwny2GAFND5QFbqgdrxaFU/1LR2+5E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rEQNF9ui0eZ6+n2JqhyQALTQISotn2wUfz6+/DdZu91iTH36BuzstUhX1Q2Tf+pah mmSnQE+QzeWHppzukIKcSGZ8Ck/iOhx9uZdZW1dz46aJ/3V+SkSWadauEo3sjoB0lh w+fTjvZK9TiC5cOQ3he+e9RsYOgLwmPkyuRvbEcc= 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 6.10 068/375] fscache: delete fscache_cookie_lru_timer when fscache exits to avoid UAF Date: Tue, 10 Sep 2024 11:27:45 +0200 Message-ID: <20240910092624.499929110@linuxfoundation.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240910092622.245959861@linuxfoundation.org> References: <20240910092622.245959861@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 6.10-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/netfs/fscache_main.c | 1 + 1 file changed, 1 insertion(+) --- a/fs/netfs/fscache_main.c +++ b/fs/netfs/fscache_main.c @@ -103,6 +103,7 @@ 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("FS-Cache unloaded\n"); }