From 3cef4110bee88ac81dfb5e62c2a8b7902248abba Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Christian=20G=C3=B6ttsche?= Date: Mon, 10 May 2021 12:56:48 +0200 Subject: [PATCH] libselinux: do not use status page fallback mode internally MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently `avc_init_internal()`, called by `avc_open(3)` and `avc_init(3)`, does open the SELinux status page with fallback mode enabled. Quote from man:selinux_status_open(3): In this case, this function tries to open a netlink socket using .BR avc_netlink_open (3) and overwrite corresponding callbacks (setenforce and policyload). Thus, we need to pay attention to the interaction with these interfaces, when fallback mode is enabled. Calling `selinux_status_open` internally in fallback mode is bad, cause it overrides callbacks from client applications or the internal fallback-callbacks get overridden by client applications. Note that `avc_open(3)` gets called under the hood by `selinux_check_access(3)` without checking for failure. Also the status page is available since Linux 2.6.37, so failures of `selinux_status_open(3)` in non-fallback mode should only be caused by policies not allowing the client process to open/read/map the /sys/fs/selinux/status file. Signed-off-by: Christian Göttsche --- libselinux/src/avc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libselinux/src/avc.c b/libselinux/src/avc.c index 8314d7ba3de6..daaedbc6a6fd 100644 --- a/libselinux/src/avc.c +++ b/libselinux/src/avc.c @@ -214,7 +214,7 @@ static int avc_init_internal(const char *prefix, avc_enforcing = rc; } - rc = selinux_status_open(1); + rc = selinux_status_open(0); if (rc < 0) { avc_log(SELINUX_ERROR, "%s: could not open selinux status page: %d (%s)\n", -- 2.32.0