From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793831157; b=TPI+PUzVnnmQBhmcgJsXdJJ4fi+YI9gAzv9YtT8MVv4jASt2JqW1V5l/5LGKsWvrJL0o hCEMs2JE0HPMq4BNgTMcViKaY6dj38sx4wJx0+7O1EBbcR3Eq9q5lSOFkxCnx3yd4JJNp z0aEJX7QloqV/aZJYUSNBlbbbpN6StPvWRSRXtmkGXp6uVOFgb4mK8OKAG8RJc8sDiDta gL+VpstCZlK5JYIk222V+ln8tauXIAUO7HEGEPQSs4Wpz44SMkYydCxnuw23q1RmeGLaB eoNsMwp0C0Y081XHbS3QvI36tatWU04gu3IXkudYwUcIiMrdW23UyQZc69ufzn3lUMg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793831157; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=dDzByZNkbplvULD5vzVsDTqV3CzWyHkEuc3rX+pxiXY=; b=DuiLW60r4l49gxyf94eGUogiD/ZghwHXfv32OIcD2+j79Ih4+c79yJB1OW71xbTiFkIK hMs6/5vgCAGKyUuqVnTCQEbtu/pFXBJz8kElqFzdpb3gVeX/XZ+0NvEmxtsJtFes9K7ul o+lT+RiH5CzAaWj3r0sTmyMfunLRkHSKJJoOiayln5xHfqVsxJgbVuTM+EgdXpBSyZcGk 1u0tVa0IZfwUpS74BZb6zA7SXQfdDr0dgAwWgh4vXAqK4xz5hwloWLpqsDxeppqIVMLqC N8Iem1dfqhqxIaPKdm7hjJxKZY7QNBpQ3TrTlC9aa11RfGYl1DaXoEfIGq6Owq9iNwg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=WrC8wVOK; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 73947606D839; Wed, 4 Nov 2026 22:25:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=WrC8wVOK Received: by smtp.kernel.org (Postfix) with ESMTPSA id C2CA71F000C1; Wed, 4 Nov 2026 22:25:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793831157; bh=dDzByZNkbplvULD5vzVsDTqV3CzWyHkEuc3rX+pxiXY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=WrC8wVOKvti8dOegdd1d+tPWujZD6S+qFrs0YH7MkdRkLPS3BbIHldcN3SONsKlmn CNERlI7rtNxquEW4EC2jJDGXSp2A2vB9Qqu9A0092B6yK55i6iJ2D2TC/XTM/X3wmy sNmLFTwLK4dtQx7YDXOv9m3nt2tPT47zlwWw2cDg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Cen Zhang , Andrew Morton , Heming Zhao , Joseph Qi , Mark Fasheh , Joel Becker , Gang He , Jia-Ju Bai , jjzuming@gmail.com Subject: [PATCH 6.18 0532/1005] ocfs2: publish the filecheck owner before adding sysfs attributes Date: Wed, 4 Nov 2026 16:04:25 -0500 Message-ID: <20261104211058.808890881@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261104211043.516122098@linuxfoundation.org> References: <20261104211043.516122098@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Cen Zhang commit e062baf5680845705d21df415c8f0751c96b0792 upstream. ocfs2_filecheck_create_sysfs() initializes the filecheck allocation before calling kobject_init_and_add(), but assigns entry->fs_fcheck only after that call returns. The default attribute group can already be visible while registration is in progress. A concurrent read can therefore enter ocfs2_filecheck_attr_show() with a NULL fs_fcheck and try to lock its fc_lock. Assign the initialized owner before adding the kobject, so every activated attribute has valid state. Clear the pointer when addition fails, preserving the existing teardown guard and error cleanup. A controlled probe-instrumented test kernel with the original OCFS2 registration ordering produced this Oops during a concurrent sysfs read: KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] RIP: 0010:kasan_byte_accessible+0x15/0x30 Call Trace: __kasan_check_byte+0x13/0x50 lock_acquire+0x113/0x300 _raw_spin_lock+0x31/0x40 ocfs2_filecheck_attr_show+0x138/0x5f0 ocfs2_filecheck_show+0x5d/0x90 sysfs_kf_seq_show+0x1d3/0x360 seq_read_iter+0x480/0x1110 kernfs_fop_read_iter+0x419/0x5a0 vfs_read+0x7d2/0xc20 ksys_read+0x111/0x200 do_syscall_64+0x114/0x620 entry_SYSCALL_64_after_hwframe+0x77/0x7f Modules linked in: Link: https://lore.kernel.org/pm-ocfs2-objects-candidate-0086-v4-1b3a3c5fd05c1fb41df9@gmail.com Fixes: 5f483c4abb50 ("ocfs2: add kobject for online file check") Signed-off-by: Cen Zhang Signed-off-by: Andrew Morton Reviewed-by: Heming Zhao Reviewed-by: Joseph Qi Assisted-by: LLM Cc: Mark Fasheh Cc: Joel Becker Cc: Gang He Cc: Jia-Ju Bai Cc: Cc: Signed-off-by: Greg Kroah-Hartman --- fs/ocfs2/filecheck.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/fs/ocfs2/filecheck.c +++ b/fs/ocfs2/filecheck.c @@ -179,17 +179,20 @@ int ocfs2_filecheck_create_sysfs(struct fcheck->fc_size = 0; fcheck->fc_done = 0; + /* Publish the initialized owner before activating its sysfs callbacks. */ + entry->fs_fcheck = fcheck; entry->fs_kobj.kset = osb->osb_dev_kset; init_completion(&entry->fs_kobj_unregister); ret = kobject_init_and_add(&entry->fs_kobj, &ocfs2_ktype_filecheck, NULL, "filecheck"); if (ret) { + /* Mount failure still calls ocfs2_filecheck_remove_sysfs(). */ + entry->fs_fcheck = NULL; kobject_put(&entry->fs_kobj); kfree(fcheck); return ret; } - entry->fs_fcheck = fcheck; return 0; }