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 2E8B613E3E4 for ; Thu, 13 Jun 2024 10:11:36 +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=1718273497; cv=none; b=GLCD0b5DKnMbhkXfvKsAcrEVrFqPHTSj762aBiMAGAODOay0gzjLOFhVPo4GJ6iYS27o+5XhwceRL867JNy6Ef+geTYEIT3HCmyKf2Ug0ad6BOkELPvc+bV8wUY1/aolIStAtpKB9mssHXwhNBUDV1G4+msWCPQSBWV541kC4zo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718273497; c=relaxed/simple; bh=y7U8i42HhXQ/QU9PPndWgg/LLxiGuQDUuioYabxvbBg=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=omY+inkYPj73sy+8GCG0UzW/aYf2+5QWB8VT4E+HpJnMJQrIiZCRhkboI0yElqXcnf/MmLZ5SPSguXUfEL5gbopCgVSuBHSXUBBvmYDWGBOxpcas6evYBdRGbGdC0X/chG3/W2ka7DeuOTwCXEvZTDijEiNLXpkD0ceV/lneckw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=dVMgDxPw; 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="dVMgDxPw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5CC6BC3277B; Thu, 13 Jun 2024 10:11:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1718273496; bh=y7U8i42HhXQ/QU9PPndWgg/LLxiGuQDUuioYabxvbBg=; h=Subject:To:Cc:From:Date:From; b=dVMgDxPwlLcO0ThEloEplc5HP70qfueHG2VEFN3GnWVr39NbVgOriHEHwoVEobPif y4+hq159INCY0YZAlqaK358ZQK9ieONEpM5EnKyJ5fjGE8Q3OV8A/z7blbXHCeA0nX hyure0BHgkUSsRGcvOWzRx8KlQe8b8WgkVrZGbME= Subject: FAILED: patch "[PATCH] 9p: add missing locking around taking dentry fid list" failed to apply to 5.15-stable tree To: asmadeus@codewreck.org,linux_oss@crudebyte.com Cc: From: Date: Thu, 13 Jun 2024 12:11:33 +0200 Message-ID: <2024061333-wincing-tackle-2315@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 5.15-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-5.15.y git checkout FETCH_HEAD git cherry-pick -x c898afdc15645efb555acb6d85b484eb40a45409 # git commit -s git send-email --to '' --in-reply-to '2024061333-wincing-tackle-2315@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: c898afdc1564 ("9p: add missing locking around taking dentry fid list") b48dbb998d70 ("9p fid refcount: add p9_fid_get/put wrappers") 47b1e3432b06 ("9p: Remove unnecessary variable for old fids while walking from d_parent") cba83f47fc0e ("9p: Track the root fid with its own variable during lookups") b0017602fdf6 ("9p: fix EBADF errors in cached mode") 2a3dcbccd64b ("9p: Fix refcounting during full path walks for fid lookups") beca774fc51a ("9p: fix fid refcount leak in v9fs_vfs_atomic_open_dotl") 6e195b0f7c8e ("9p: fix a bunch of checkpatch warnings") eb497943fa21 ("9p: Convert to using the netfs helper lib to do reads and caching") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From c898afdc15645efb555acb6d85b484eb40a45409 Mon Sep 17 00:00:00 2001 From: Dominique Martinet Date: Tue, 21 May 2024 21:13:36 +0900 Subject: [PATCH] 9p: add missing locking around taking dentry fid list Fix a use-after-free on dentry's d_fsdata fid list when a thread looks up a fid through dentry while another thread unlinks it: UAF thread: refcount_t: addition on 0; use-after-free. p9_fid_get linux/./include/net/9p/client.h:262 v9fs_fid_find+0x236/0x280 linux/fs/9p/fid.c:129 v9fs_fid_lookup_with_uid linux/fs/9p/fid.c:181 v9fs_fid_lookup+0xbf/0xc20 linux/fs/9p/fid.c:314 v9fs_vfs_getattr_dotl+0xf9/0x360 linux/fs/9p/vfs_inode_dotl.c:400 vfs_statx+0xdd/0x4d0 linux/fs/stat.c:248 Freed by: p9_fid_destroy (inlined) p9_client_clunk+0xb0/0xe0 linux/net/9p/client.c:1456 p9_fid_put linux/./include/net/9p/client.h:278 v9fs_dentry_release+0xb5/0x140 linux/fs/9p/vfs_dentry.c:55 v9fs_remove+0x38f/0x620 linux/fs/9p/vfs_inode.c:518 vfs_unlink+0x29a/0x810 linux/fs/namei.c:4335 The problem is that d_fsdata was not accessed under d_lock, because d_release() normally is only called once the dentry is otherwise no longer accessible but since we also call it explicitly in v9fs_remove that lock is required: move the hlist out of the dentry under lock then unref its fids once they are no longer accessible. Fixes: 154372e67d40 ("fs/9p: fix create-unlink-getattr idiom") Cc: stable@vger.kernel.org Reported-by: Meysam Firouzi Reported-by: Amirmohammad Eftekhar Reviewed-by: Christian Schoenebeck Message-ID: <20240521122947.1080227-1-asmadeus@codewreck.org> Signed-off-by: Dominique Martinet diff --git a/fs/9p/vfs_dentry.c b/fs/9p/vfs_dentry.c index f16f73581634..01338d4c2d9e 100644 --- a/fs/9p/vfs_dentry.c +++ b/fs/9p/vfs_dentry.c @@ -48,12 +48,17 @@ static int v9fs_cached_dentry_delete(const struct dentry *dentry) static void v9fs_dentry_release(struct dentry *dentry) { struct hlist_node *p, *n; + struct hlist_head head; p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p)\n", dentry, dentry); - hlist_for_each_safe(p, n, (struct hlist_head *)&dentry->d_fsdata) + + spin_lock(&dentry->d_lock); + hlist_move_list((struct hlist_head *)&dentry->d_fsdata, &head); + spin_unlock(&dentry->d_lock); + + hlist_for_each_safe(p, n, &head) p9_fid_put(hlist_entry(p, struct p9_fid, dlist)); - dentry->d_fsdata = NULL; } static int v9fs_lookup_revalidate(struct dentry *dentry, unsigned int flags)