diff options
| -rw-r--r-- | src/rc/checkpath.c | 44 |
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; |