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 1C66878B61; Tue, 27 Feb 2024 14:18:15 +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=1709043495; cv=none; b=rQbN1k0+Ne6T7o2/+LYWkHqRpDHregoD4YnJO+3U7kN0qW3wYg2qPTd+iKMem9Uh9N3/eJAx4loZs6v9YdhvV8f3hF8b5ZNHR/lSXP+zrIQ7L09MmKwCzRmv7RENpUeVV6Jl43eh2rExVvrc+XUG0Yj9xldBfsXdql7b/IasMiQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709043495; c=relaxed/simple; bh=ZPIrUjQfaRp5Kf7S9ttsPY9vJrCa8wqieksMJiRDzVw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=beHdhk6vw6WEvuQ24kKmsEs0AfDXCV9tILsy02zuOL1d6fBl+4pApP9yPS0mgvWdDoW7elbVGCWhClYmkMw8zeAMr6lvXklYMIJRL7ilaiJxi0l583edlDxnh/C5b4AZVqQfaaLCOv/E2HBE7OebqxS8nX2giCawPDMU0D+8jl4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=qewofy37; 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="qewofy37" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9E201C433F1; Tue, 27 Feb 2024 14:18:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1709043495; bh=ZPIrUjQfaRp5Kf7S9ttsPY9vJrCa8wqieksMJiRDzVw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qewofy37oUbWTWnYpsRRdve5Pwq14aHQFLXC6JJ2DWECUniGJP7nD82qIW+zbYJ9J JXHgvVE1hF6jncHWc1pRkZai4NOuQAtuM2yRd6ockH+ff9bjhNNpHKCo3Enth7Hi3o sHwlTNG14f7XScleHv/AdusamHmQyEFlyiJrapAM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Baokun Li , David Howells , Jingbo Xu , Jeff Layton , Christian Brauner Subject: [PATCH 6.1 101/195] cachefiles: fix memory leak in cachefiles_add_cache() Date: Tue, 27 Feb 2024 14:26:02 +0100 Message-ID: <20240227131613.808225072@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240227131610.391465389@linuxfoundation.org> References: <20240227131610.391465389@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Baokun Li commit e21a2f17566cbd64926fb8f16323972f7a064444 upstream. The following memory leak was reported after unbinding /dev/cachefiles: ================================================================== unreferenced object 0xffff9b674176e3c0 (size 192): comm "cachefilesd2", pid 680, jiffies 4294881224 hex dump (first 32 bytes): 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace (crc ea38a44b): [] kmem_cache_alloc+0x2d5/0x370 [] prepare_creds+0x26/0x2e0 [] cachefiles_determine_cache_security+0x1f/0x120 [] cachefiles_add_cache+0x13c/0x3a0 [] cachefiles_daemon_write+0x146/0x1c0 [] vfs_write+0xcb/0x520 [] ksys_write+0x69/0xf0 [] do_syscall_64+0x72/0x140 [] entry_SYSCALL_64_after_hwframe+0x6e/0x76 ================================================================== Put the reference count of cache_cred in cachefiles_daemon_unbind() to fix the problem. And also put cache_cred in cachefiles_add_cache() error branch to avoid memory leaks. Fixes: 9ae326a69004 ("CacheFiles: A cache that backs onto a mounted filesystem") CC: stable@vger.kernel.org Signed-off-by: Baokun Li Link: https://lore.kernel.org/r/20240217081431.796809-1-libaokun1@huawei.com Acked-by: David Howells Reviewed-by: Jingbo Xu Reviewed-by: Jeff Layton Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman --- fs/cachefiles/cache.c | 2 ++ fs/cachefiles/daemon.c | 1 + 2 files changed, 3 insertions(+) --- a/fs/cachefiles/cache.c +++ b/fs/cachefiles/cache.c @@ -168,6 +168,8 @@ error_unsupported: dput(root); error_open_root: cachefiles_end_secure(cache, saved_cred); + put_cred(cache->cache_cred); + cache->cache_cred = NULL; error_getsec: fscache_relinquish_cache(cache_cookie); cache->cache = NULL; --- a/fs/cachefiles/daemon.c +++ b/fs/cachefiles/daemon.c @@ -805,6 +805,7 @@ static void cachefiles_daemon_unbind(str cachefiles_put_directory(cache->graveyard); cachefiles_put_directory(cache->store); mntput(cache->mnt); + put_cred(cache->cache_cred); kfree(cache->rootdirname); kfree(cache->secctx);