From d3efa43d85ac132c6a5a416a2b6f2115f5d577ee Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 2 Mar 2010 21:33:34 -0800 Subject: [PATCH] core-util: ensure that we chmod only the dir we ourselves created --- configure.ac | 2 +- src/pulsecore/core-util.c | 39 ++++++++++++++++++++++++++++++++++----- 2 files changed, 35 insertions(+), 6 deletions(-) Index: pulseaudio-0.9.15/configure.ac =================================================================== --- pulseaudio-0.9.15.orig/configure.ac 2010-03-17 14:50:02.000000000 +0800 +++ pulseaudio-0.9.15/configure.ac 2010-03-17 14:52:27.250075828 +0800 @@ -403,7 +403,7 @@ AC_FUNC_FORK AC_FUNC_GETGROUPS AC_FUNC_SELECT_ARGTYPES -AC_CHECK_FUNCS([chmod chown clock_gettime getaddrinfo getgrgid_r getgrnam_r \ +AC_CHECK_FUNCS([chmod chown fstat fchown fchmod clock_gettime getaddrinfo getgrgid_r getgrnam_r \ getpwnam_r getpwuid_r gettimeofday getuid inet_ntop inet_pton mlock nanosleep \ pipe posix_fadvise posix_madvise posix_memalign setpgid setsid shm_open \ sigaction sleep sysconf pthread_setaffinity_np]) Index: pulseaudio-0.9.15/src/pulsecore/core-util.c =================================================================== --- pulseaudio-0.9.15.orig/src/pulsecore/core-util.c 2010-03-17 14:49:59.000000000 +0800 +++ pulseaudio-0.9.15/src/pulsecore/core-util.c 2010-03-17 14:51:37.680079062 +0800 @@ -178,7 +178,7 @@ /** Creates a directory securely */ int pa_make_secure_dir(const char* dir, mode_t m, uid_t uid, gid_t gid) { struct stat st; - int r, saved_errno; + int r, saved_errno, fd; pa_assert(dir); @@ -196,16 +196,45 @@ if (r < 0 && errno != EEXIST) return -1; -#ifdef HAVE_CHOWN +#ifdef HAVE_FSTAT + if ((fd = open(dir, +#ifdef O_CLOEXEC + O_CLOEXEC| +#endif +#ifdef O_NOCTTY + O_NOCTTY| +#endif +#ifdef O_NOFOLLOW + O_NOFOLLOW| +#endif + O_RDONLY)) < 0) + goto fail; + + if (fstat(fd, &st) < 0) { + pa_assert_se(pa_close(fd) >= 0); + goto fail; + } + + if (!S_ISDIR(st.st_mode)) { + pa_assert_se(pa_close(fd) >= 0); + errno = EEXIST; + goto fail; + } + +#ifdef HAVE_FCHOWN if (uid == (uid_t)-1) uid = getuid(); if (gid == (gid_t)-1) gid = getgid(); - (void) chown(dir, uid, gid); + (void) fchown(fd, uid, gid); +#endif + +#ifdef HAVE_FCHMOD + (void) fchmod(fd, m); #endif -#ifdef HAVE_CHMOD - chmod(dir, m); + pa_assert_se(pa_close(fd) >= 0); + #endif #ifdef HAVE_LSTAT