From 533deafbdf189f5fbb280c28562dd43ace2f4b0f Mon Sep 17 00:00:00 2001 From: Sergey Bugaev Date: Wed, 19 Apr 2023 19:02:03 +0300 Subject: [PATCH] Use O_CLOEXEC in more places (BZ #15722) When opening a temporary file without O_CLOEXEC we risk leaking the file descriptor if another thread calls (fork and then) exec while we have the fd open. Fix this by consistently passing O_CLOEXEC everywhere where we open a file for internal use (and not to return it to the user, in which case the API defines whether or not the close-on-exec flag shall be set on the returned fd). Reviewed-by: Adhemerval Zanella Signed-off-by: Sergey Bugaev Message-Id: <20230419160207.65988-4-bugaevc@gmail.com> --- catgets/open_catalog.c | 4 ++-- elf/dl-profile.c | 3 ++- gmon/gmon.c | 7 ++++--- iconv/gconv_cache.c | 2 +- login/utmp_file.c | 2 +- sysdeps/pthread/sem_open.c | 9 ++++++--- 6 files changed, 16 insertions(+), 11 deletions(-) diff --git a/catgets/open_catalog.c b/catgets/open_catalog.c index 242709db73d..46c444d2599 100644 --- a/catgets/open_catalog.c +++ b/catgets/open_catalog.c @@ -49,7 +49,7 @@ __open_catalog (const char *cat_name, const char *nlspath, const char *env_var, char *buf = NULL; if (strchr (cat_name, '/') != NULL || nlspath == NULL) - fd = __open_nocancel (cat_name, O_RDONLY); + fd = __open_nocancel (cat_name, O_RDONLY | O_CLOEXEC); else { const char *run_nlspath = nlspath; @@ -177,7 +177,7 @@ __open_catalog (const char *cat_name, const char *nlspath, const char *env_var, if (bufact != 0) { - fd = __open_nocancel (buf, O_RDONLY); + fd = __open_nocancel (buf, O_RDONLY | O_CLOEXEC); if (fd >= 0) break; } diff --git a/elf/dl-profile.c b/elf/dl-profile.c index 2ecac05f8df..d8345da22e5 100644 --- a/elf/dl-profile.c +++ b/elf/dl-profile.c @@ -324,7 +324,8 @@ _dl_start_profile (void) *cp++ = '/'; __stpcpy (__stpcpy (cp, GLRO(dl_profile)), ".profile"); - fd = __open64_nocancel (filename, O_RDWR|O_CREAT|O_NOFOLLOW, DEFFILEMODE); + fd = __open64_nocancel (filename, O_RDWR | O_CREAT | O_NOFOLLOW + | O_CLOEXEC, DEFFILEMODE); if (fd == -1) { char buf[400]; diff --git a/gmon/gmon.c b/gmon/gmon.c index bc0e29438a0..6439ed1caa1 100644 --- a/gmon/gmon.c +++ b/gmon/gmon.c @@ -384,13 +384,14 @@ write_gmon (void) size_t len = strlen (env); char buf[len + 20]; __snprintf (buf, sizeof (buf), "%s.%u", env, __getpid ()); - fd = __open_nocancel (buf, O_CREAT|O_TRUNC|O_WRONLY|O_NOFOLLOW, 0666); + fd = __open_nocancel (buf, O_CREAT | O_TRUNC | O_WRONLY | O_NOFOLLOW + | O_CLOEXEC, 0666); } if (fd == -1) { - fd = __open_nocancel ("gmon.out", O_CREAT|O_TRUNC|O_WRONLY|O_NOFOLLOW, - 0666); + fd = __open_nocancel ("gmon.out", O_CREAT | O_TRUNC | O_WRONLY + | O_NOFOLLOW | O_CLOEXEC, 0666); if (fd < 0) { char buf[300]; diff --git a/iconv/gconv_cache.c b/iconv/gconv_cache.c index f2100ca88f9..87136e2402c 100644 --- a/iconv/gconv_cache.c +++ b/iconv/gconv_cache.c @@ -58,7 +58,7 @@ __gconv_load_cache (void) return -1; /* See whether the cache file exists. */ - fd = __open_nocancel (GCONV_MODULES_CACHE, O_RDONLY, 0); + fd = __open_nocancel (GCONV_MODULES_CACHE, O_RDONLY | O_CLOEXEC, 0); if (__builtin_expect (fd, 0) == -1) /* Not available. */ return -1; diff --git a/login/utmp_file.c b/login/utmp_file.c index 53494595812..1ef07821397 100644 --- a/login/utmp_file.c +++ b/login/utmp_file.c @@ -463,7 +463,7 @@ __libc_updwtmp (const char *file, const struct utmp *utmp) int fd; /* Open WTMP file. */ - fd = __open_nocancel (file, O_WRONLY | O_LARGEFILE); + fd = __open_nocancel (file, O_WRONLY | O_LARGEFILE | O_CLOEXEC); if (fd < 0) return -1; diff --git a/sysdeps/pthread/sem_open.c b/sysdeps/pthread/sem_open.c index 2d32a13557e..e5db929d205 100644 --- a/sysdeps/pthread/sem_open.c +++ b/sysdeps/pthread/sem_open.c @@ -36,6 +36,7 @@ sem_t * __sem_open (const char *name, int oflag, ...) { int fd; + int open_flags; sem_t *result; /* Check that shared futexes are supported. */ @@ -64,9 +65,10 @@ __sem_open (const char *name, int oflag, ...) /* If the semaphore object has to exist simply open it. */ if ((oflag & O_CREAT) == 0 || (oflag & O_EXCL) == 0) { + open_flags = O_RDWR | O_NOFOLLOW | O_CLOEXEC; + open_flags |= (oflag & ~(O_CREAT|O_ACCMODE)); try_again: - fd = __open (dirname.name, - (oflag & ~(O_CREAT|O_ACCMODE)) | O_NOFOLLOW | O_RDWR); + fd = __open (dirname.name, open_flags); if (fd == -1) { @@ -133,7 +135,8 @@ __sem_open (const char *name, int oflag, ...) } /* Open the file. Make sure we do not overwrite anything. */ - fd = __open (tmpfname, O_RDWR | O_CREAT | O_EXCL, mode); + open_flags = O_RDWR | O_CREAT | O_EXCL | O_CLOEXEC; + fd = __open (tmpfname, open_flags, mode); if (fd == -1) { if (errno == EEXIST) -- 2.39.2