From: Donald Chan <hoiho@amazon.com>
Date: Fri, 28 Jan 2022 22:53:46 +0000 (+0000)
Subject: basic: mac_[selinux,smack]_apply_fd does not work when applying labels
X-Git-Tag: v251-rc1~418
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a718364e9d9242cc2111c9860f2ab5bb9bb26db9;p=thirdparty%2Fsystemd.git

basic: mac_[selinux,smack]_apply_fd does not work when applying labels

Commit a7fdc6c introduced a regression where file descriptors are opened
using O_PATH option. mac_smack_apply_fd() calls fsetxattr() and would fail
with a -EBADF (Bad file descriptor) error.

Use FORMAT_PROC_FD_PATH(fd) to convert the fd back into a full path and
call setxattr() or setfilecon() instead.

Signed-off-by: Donald Chan <hoiho@amazon.com>
---

diff --git a/src/shared/selinux-util.c b/src/shared/selinux-util.c
index a1359a5bfd3..67ea8581422 100644
--- a/src/shared/selinux-util.c
+++ b/src/shared/selinux-util.c
@@ -346,7 +346,7 @@ int mac_selinux_apply_fd(int fd, const char *path, const char *label) {
 
         assert(label);
 
-        if (fsetfilecon(fd, label) < 0)
+        if (setfilecon(FORMAT_PROC_FD_PATH(fd), label) < 0)
                 return log_enforcing_errno(errno, "Failed to set SELinux security context %s on path %s: %m", label, strna(path));
 #endif
         return 0;
diff --git a/src/shared/smack-util.c b/src/shared/smack-util.c
index b8434b068ca..0df1778cb2d 100644
--- a/src/shared/smack-util.c
+++ b/src/shared/smack-util.c
@@ -95,9 +95,9 @@ int mac_smack_apply_fd(int fd, SmackAttr attr, const char *label) {
                 return 0;
 
         if (label)
-                r = fsetxattr(fd, smack_attr_to_string(attr), label, strlen(label), 0);
+                r = setxattr(FORMAT_PROC_FD_PATH(fd), smack_attr_to_string(attr), label, strlen(label), 0);
         else
-                r = fremovexattr(fd, smack_attr_to_string(attr));
+                r = removexattr(FORMAT_PROC_FD_PATH(fd), smack_attr_to_string(attr));
         if (r < 0)
                 return -errno;