From d8a3bd0d464f5b75ac360f4ee4e3cc6927a09199 Mon Sep 17 00:00:00 2001 From: Jakub Filak Date: Wed, 30 Sep 2015 14:13:35 +0200 Subject: [PATCH] lib: add convenient wrappers for ensuring writable dir Replace lchown with fchown and chmod with fchmod. Related CVE-2015-5287 Signed-off-by: Jakub Filak --- src/include/libabrt.h | 4 ++++ src/lib/hooklib.c | 41 ++++++++++++++++++++++++++++++++++------- 2 files changed, 38 insertions(+), 7 deletions(-) diff --git a/src/include/libabrt.h b/src/include/libabrt.h index 6f89959..b26dcc6 100644 --- a/src/include/libabrt.h +++ b/src/include/libabrt.h @@ -42,8 +42,12 @@ int low_free_space(unsigned setting_MaxCrashReportsSize, const char *dump_locati #define trim_problem_dirs abrt_trim_problem_dirs void trim_problem_dirs(const char *dirname, double cap_size, const char *exclude_path); +#define ensure_writable_dir_id abrt_ensure_writable_dir_uid_git +void ensure_writable_dir_uid_gid(const char *dir, mode_t mode, uid_t uid, gid_t gid); #define ensure_writable_dir abrt_ensure_writable_dir void ensure_writable_dir(const char *dir, mode_t mode, const char *user); +#define ensure_writable_dir_group abrt_ensure_writable_dir_group +void ensure_writable_dir_group(const char *dir, mode_t mode, const char *user, const char *group); #define run_unstrip_n abrt_run_unstrip_n char *run_unstrip_n(const char *dump_dir_name, unsigned timeout_sec); #define get_backtrace abrt_get_backtrace diff --git a/src/lib/hooklib.c b/src/lib/hooklib.c index 2b76eea..0daa144 100644 --- a/src/lib/hooklib.c +++ b/src/lib/hooklib.c @@ -476,23 +476,50 @@ int signal_is_fatal(int signal_no, const char **name) return signame != NULL; } -void ensure_writable_dir(const char *dir, mode_t mode, const char *user) +void ensure_writable_dir_uid_gid(const char *dir, mode_t mode, uid_t uid, gid_t gid) { struct stat sb; + int dir_fd; if (mkdir(dir, mode) != 0 && errno != EEXIST) perror_msg_and_die("Can't create '%s'", dir); - if (stat(dir, &sb) != 0 || !S_ISDIR(sb.st_mode)) - error_msg_and_die("'%s' is not a directory", dir); + dir_fd = open(dir, O_DIRECTORY | O_NOFOLLOW); + if (dir_fd < 0) + perror_msg_and_die("Can't open directory '%s'", dir); + + if (fstat(dir_fd, &sb) != 0) + perror_msg_and_die("Can't stat directory '%s'", dir); + + if ((sb.st_uid != uid || sb.st_gid != gid) && fchown(dir_fd, uid, gid) != 0) + perror_msg_and_die("Can't set owner %u:%u on '%s'", (unsigned int)uid, (unsigned int)gid, dir); + + if ((sb.st_mode & 07777) != mode && fchmod(dir_fd, mode) != 0) + perror_msg_and_die("Can't set mode %o on '%s'", mode, dir); + + close(dir_fd); +} + +void ensure_writable_dir(const char *dir, mode_t mode, const char *user) +{ + struct passwd *pw = getpwnam(user); + if (!pw) + perror_msg_and_die("Can't find user '%s'", user); + + ensure_writable_dir_uid_gid(dir, mode, pw->pw_uid, pw->pw_gid); +} + +void ensure_writable_dir_group(const char *dir, mode_t mode, const char *user, const char *group) +{ struct passwd *pw = getpwnam(user); if (!pw) perror_msg_and_die("Can't find user '%s'", user); - if ((sb.st_uid != pw->pw_uid || sb.st_gid != pw->pw_gid) && lchown(dir, pw->pw_uid, pw->pw_gid) != 0) - perror_msg_and_die("Can't set owner %u:%u on '%s'", (unsigned int)pw->pw_uid, (unsigned int)pw->pw_gid, dir); - if ((sb.st_mode & 07777) != mode && chmod(dir, mode) != 0) - perror_msg_and_die("Can't set mode %o on '%s'", mode, dir); + struct group *gr = getgrnam(group); + if (!gr) + perror_msg_and_die("Can't find group '%s'", group); + + ensure_writable_dir_uid_gid(dir, mode, pw->pw_uid, gr->gr_gid); } bool dir_is_in_dump_location(const char *dir_name) -- 2.6.3