Re: [RFC PATCH v2 3/7] Use O_CLOEXEC in more places (BZ #15722)

[Samuel Thibault]

Applied, thanks!

Adhemerval Zanella Netto, le ven. 21 avril 2023 09:55:58 -0300, a ecrit:
> 
> 
> On 19/04/23 13:02, Sergey Bugaev wrote:
> > 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 <adhemerval.zanella@linaro.org>
> > Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
> 
> LGTM, thanks.  I can be installed independently.
> 
> > ---
> >  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 242709db..46c444d2 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 2ecac05f..d8345da2 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 bc0e2943..6439ed1c 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 f2100ca8..87136e24 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 53494595..1ef07821 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 2d32a135..e5db929d 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)
> 

-- 
Samuel
---
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