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 2CD83156668 for ; Sun, 8 Sep 2024 12:23:48 +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=1725798229; cv=none; b=a7pwWeWYp+fG9igTBA4hrYxXVl3YavERuPNJucBSn/E9PK2eQQ5xxGZW9l71KD7+pGCjDWUNKcnlJ5vE9yIfeiqoBjY0omutiQVKT8c1TdDnilKa/ZjmhdnnwFoKHQxOFV34MG4Aa73OowA7VrnuH4Dr2sWAbZoSdQ03V9W53Xw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725798229; c=relaxed/simple; bh=NwR+Nbk01fWcfrONkFV4RKEexI8ZbrQypTL4tRfgi0Q=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=RYyrU0X28cODFFLvDysvxBthgVCTzHItMuulOTBFc48ZaeWPJnL3DryqB0SUJNsXfxs9rfXERggzJbheQHtIYpmPe7XlOC/kz62TFFqATzZkzda1fCnQ3efHJ+YmKUlxkTSCRSv1wl2KSmbo9vUrCknFbIL9fo3l6LaNWvGyHBk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=xMqpvCIf; 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="xMqpvCIf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 68F3AC4CEC3; Sun, 8 Sep 2024 12:23:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1725798228; bh=NwR+Nbk01fWcfrONkFV4RKEexI8ZbrQypTL4tRfgi0Q=; h=Subject:To:Cc:From:Date:From; b=xMqpvCIfG+aVvjqu6bqKvODxSOuEygkHPiDvC1cMLHjnYBaFl9BJfvqIgPb12Zkwl xRcJHIG1MbiBVBbgg16lZ53PxrBHkajP0MAm+6DLKP40akZcInaV0R85Qd6NnW1SgG tpQ6tWESsyT+0p9LTL+ITjZXcuqiq0R4RwOWeAT0= Subject: FAILED: patch "[PATCH] fscache: delete fscache_cookie_lru_timer when fscache exits" failed to apply to 6.1-stable tree To: libaokun1@huawei.com,brauner@kernel.org,dhowells@redhat.com Cc: From: Date: Sun, 08 Sep 2024 14:23:39 +0200 Message-ID: <2024090838-thus-fiftieth-f4f7@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 72a6e22c604c95ddb3b10b5d3bb85b6ff4dbc34f # git commit -s git send-email --to '' --in-reply-to '2024090838-thus-fiftieth-f4f7@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: 72a6e22c604c ("fscache: delete fscache_cookie_lru_timer when fscache exits to avoid UAF") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 72a6e22c604c95ddb3b10b5d3bb85b6ff4dbc34f Mon Sep 17 00:00:00 2001 From: Baokun Li Date: Mon, 26 Aug 2024 19:20:56 +0800 Subject: [PATCH] fscache: delete fscache_cookie_lru_timer when fscache exits to avoid UAF 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 diff --git a/fs/netfs/fscache_main.c b/fs/netfs/fscache_main.c index 42e98bb523e3..49849005eb7c 100644 --- 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"); }