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Diffstat (limited to 'src/rc')
-rw-r--r--src/rc/checkpath.c44
1 files changed, 41 insertions, 3 deletions
diff --git a/src/rc/checkpath.c b/src/rc/checkpath.c
index 448c9cf8..62ee120d 100644
--- a/src/rc/checkpath.c
+++ b/src/rc/checkpath.c
@@ -16,9 +16,11 @@
* except according to the terms contained in the LICENSE file.
*/
+#define _GNU_SOURCE
#include <sys/types.h>
#include <sys/stat.h>
+#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
@@ -69,6 +71,37 @@ const char * const longopts_help[] = {
};
const char *usagestring = NULL;
+/* On Linux, fchmod() returns EBADF when passed a file descriptor opened
+ * with O_PATH. Use chmod() on /proc/self/fd as a workaround. */
+static int fchmod_opath(int fd, mode_t mode)
+{
+#ifdef O_PATH
+ /* A 64-bit int will result in a maximum path length of 35 characters. */
+ char path[35];
+
+ /* Maybe we will have 128-bit ints someday. */
+ assert(sizeof(int) <= 8);
+
+ if (sprintf(path, "/proc/self/fd/%d", fd) < 0)
+ return -1;
+
+ return chmod(path, mode);
+#else
+ return fchmod(fd, mode);
+#endif
+}
+
+/* On Linux, fchown() returns EBADF when passed a file descriptor opened
+ * with O_PATH. fchownat() does not exhibit this flaw. */
+static int fchown_opath(int fd, uid_t uid, gid_t gid)
+{
+#ifdef O_PATH
+ return fchownat(fd, "", uid, gid, AT_EMPTY_PATH);
+#else
+ return fchown(fd, uid, gid);
+#endif
+}
+
static int do_check(char *path, uid_t uid, gid_t gid, mode_t mode,
inode_t type, bool trunc, bool chowner, bool selinux_on)
{
@@ -82,7 +115,7 @@ static int do_check(char *path, uid_t uid, gid_t gid, mode_t mode,
memset(&st, 0, sizeof(st));
flags = O_CREAT|O_NDELAY|O_WRONLY|O_NOCTTY;
- readflags = O_NDELAY|O_NOCTTY|O_RDONLY;
+ readflags = O_NDELAY|O_NOCTTY;
#ifdef O_CLOEXEC
flags |= O_CLOEXEC;
readflags |= O_CLOEXEC;
@@ -91,6 +124,11 @@ static int do_check(char *path, uid_t uid, gid_t gid, mode_t mode,
flags |= O_NOFOLLOW;
readflags |= O_NOFOLLOW;
#endif
+#ifdef O_PATH
+ readflags |= O_PATH;
+#else
+ readflags |= O_RDONLY;
+#endif
if (trunc)
flags |= O_TRUNC;
readfd = open(path, readflags);
@@ -177,7 +215,7 @@ static int do_check(char *path, uid_t uid, gid_t gid, mode_t mode,
return -1;
}
einfo("%s: correcting mode", path);
- if (fchmod(readfd, mode)) {
+ if (fchmod_opath(readfd, mode)) {
eerror("%s: chmod: %s", applet, strerror(errno));
close(readfd);
return -1;
@@ -196,7 +234,7 @@ static int do_check(char *path, uid_t uid, gid_t gid, mode_t mode,
return -1;
}
einfo("%s: correcting owner", path);
- if (fchown(readfd, uid, gid)) {
+ if (fchown_opath(readfd, uid, gid)) {
eerror("%s: chown: %s", applet, strerror(errno));
close(readfd);
return -1;