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 6FA081DA4A; Tue, 16 Jan 2024 01:05:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="cCgzzAIb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 66640C433A6; Tue, 16 Jan 2024 01:05:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1705367158; bh=QXsxDVG+mDeikixD/NQuUBu5j3wwemKNZLGM6l6dV6A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cCgzzAIbimdO/4eUNWGIfayRMrIi18E1NakYVI1FMHU3QEPM3aQsMkcLuEf62MgAv ttFyz3oRhLmuTX4Kqgoj/Nh3uOUmOZ4gLoFKaLoGzG/QJz6aMFAwbDUeHQleLuqIMe OTspt0+fLoyLxy5QVq/P/ow6gN57jVYvyfyaPwRbCImXyyZcjK7oi/GRUah+50Mf8a IMVttPMUKw7HHHT+HK0UHgdjmBoveb7rAQr+k9pBXkU3UscdnBOT44u27F18A923Un iAqHN+RK4a/lcBb1ggiF1AcHAuhbsNNTUpKH+vpZqcr1AETUHPKkAm7n/vc+qxT8T3 x9mZDLRRAguUw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Joel Granados , kernel test robot , Luis Chamberlain , Sasha Levin , keescook@chromium.org, linux-fsdevel@vger.kernel.org Subject: [PATCH AUTOSEL 6.6 08/19] sysctl: Fix out of bounds access for empty sysctl registers Date: Mon, 15 Jan 2024 20:05:03 -0500 Message-ID: <20240116010532.218428-8-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240116010532.218428-1-sashal@kernel.org> References: <20240116010532.218428-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.6.12 Content-Transfer-Encoding: 8bit From: Joel Granados [ Upstream commit 315552310c7de92baea4e570967066569937a843 ] When registering tables to the sysctl subsystem there is a check to see if header is a permanently empty directory (used for mounts). This check evaluates the first element of the ctl_table. This results in an out of bounds evaluation when registering empty directories. The function register_sysctl_mount_point now passes a ctl_table of size 1 instead of size 0. It now relies solely on the type to identify a permanently empty register. Make sure that the ctl_table has at least one element before testing for permanent emptiness. Signed-off-by: Joel Granados Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202311201431.57aae8f3-oliver.sang@intel.com Signed-off-by: Luis Chamberlain Signed-off-by: Sasha Levin --- fs/proc/proc_sysctl.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index de484195f49f..5b5cdc747cef 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -44,7 +44,7 @@ static struct ctl_table sysctl_mount_point[] = { */ struct ctl_table_header *register_sysctl_mount_point(const char *path) { - return register_sysctl_sz(path, sysctl_mount_point, 0); + return register_sysctl(path, sysctl_mount_point); } EXPORT_SYMBOL(register_sysctl_mount_point); @@ -233,7 +233,8 @@ static int insert_header(struct ctl_dir *dir, struct ctl_table_header *header) return -EROFS; /* Am I creating a permanently empty directory? */ - if (sysctl_is_perm_empty_ctl_table(header->ctl_table)) { + if (header->ctl_table_size > 0 && + sysctl_is_perm_empty_ctl_table(header->ctl_table)) { if (!RB_EMPTY_ROOT(&dir->root)) return -EINVAL; sysctl_set_perm_empty_ctl_header(dir_h); @@ -1213,6 +1214,10 @@ static bool get_links(struct ctl_dir *dir, struct ctl_table_header *tmp_head; struct ctl_table *entry, *link; + if (header->ctl_table_size == 0 || + sysctl_is_perm_empty_ctl_table(header->ctl_table)) + return true; + /* Are there links available for every entry in table? */ list_for_each_table_entry(entry, header) { const char *procname = entry->procname; -- 2.43.0