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 F019A78B61; Tue, 27 Feb 2024 13:37:18 +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=1709041039; cv=none; b=IbOOmvwbzuo9e4npO9BuWse1vbIvUPpZliFtjRd4i9zL+fdm6Wzz33GeVOVkoncHNTeemVXw+ypGoKWq2g4PDgsr7nYHRQBiJGhFtdtbw+Y/R0S1xRT0l/2JH4KeW46oAwholOYdEdPkWWtRFPiRlZe1M0+KDJglTeeEhBwk9To= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709041039; c=relaxed/simple; bh=5hmIbd8Qv9Th+fom9ECoTYWh5JYZ5Ykp+iXCmHBRMzY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=T3rzZrrzJHsmVD6rvkiUu8wdoNZRZjqmDKeXcU/rKEBfO5KZn25a2RgH2ogXzhda2+5/jw4iBYBZOPhWYxy9+5nLHyCmD1KU38cKlftD30JM0HKoczNru9jDFueKjOYxF8NJgUTZw0SxXKZjJKSM6MRp/Q/Fi3wBN3E/V8TgOHU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=WoBOHkFQ; 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="WoBOHkFQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 24407C43399; Tue, 27 Feb 2024 13:37:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1709041038; bh=5hmIbd8Qv9Th+fom9ECoTYWh5JYZ5Ykp+iXCmHBRMzY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WoBOHkFQp+Q9y0MTeeEXGu9MzO1it0MH5AyZ9lkSL/zBMPq1KQOmPl9WzAWYQfFSq sQOVdWoQr+cCdVAYlpLGqT31nahCm5Oi4Jy0CBMZGsK/BgkwkM3zWJXAxEbKJOeZwz cUiA7z0GvewGrXbinykzlJY9mXc60lz4WqT75uAI= 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 6.7 180/334] cachefiles: fix memory leak in cachefiles_add_cache() Date: Tue, 27 Feb 2024 14:20:38 +0100 Message-ID: <20240227131636.412659947@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240227131630.636392135@linuxfoundation.org> References: <20240227131630.636392135@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 6.7-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);