From 65a27b0b41a8ec07407ad0415fd0963917c59941 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Tue, 24 Nov 2009 18:24:14 -0800 Subject: Prevent unintended file desriptor leak in grantpt. The pt_chown program is completely transparently called. It might not be able to live with the various file descriptors the program has open at the time of the call (e.g., under SELinux). Close all but the needed descriptor and connect stdin, stdout, and stderr with /dev/null. pt_chown shouldn't print anything when called to do real work. (cherry picked from commit 139ee080b6b428240bf49f3e6361f3ac729f891a) --- sysdeps/unix/sysv/linux/grantpt.c | 42 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 sysdeps/unix/sysv/linux/grantpt.c (limited to 'sysdeps/unix/sysv') diff --git a/sysdeps/unix/sysv/linux/grantpt.c b/sysdeps/unix/sysv/linux/grantpt.c new file mode 100644 index 0000000000..6305ed4944 --- /dev/null +++ b/sysdeps/unix/sysv/linux/grantpt.c @@ -0,0 +1,42 @@ +#include +#include +#include +#include +#include +#include +#include +#include + +#include "not-cancel.h" +#include "pty-private.h" + + +/* Close all file descriptors except the one specified. */ +static void +close_all_fds (void) +{ + DIR *dir = opendir ("/proc/self/fd"); + if (dir != NULL) + { + struct dirent64 *d; + while ((d = readdir64 (dir)) != NULL) + if (isdigit (d->d_name[0])) + { + char *endp; + long int fd = strtol (d->d_name, &endp, 10); + if (*endp == '\0' && fd != PTY_FILENO && fd != dirfd (dir)) + close_not_cancel_no_status (fd); + } + + closedir (dir); + + int nullfd = open_not_cancel_2 (_PATH_DEVNULL, O_RDONLY); + assert (nullfd == STDIN_FILENO); + nullfd = open_not_cancel_2 (_PATH_DEVNULL, O_WRONLY); + assert (nullfd == STDOUT_FILENO); + __dup2 (STDOUT_FILENO, STDERR_FILENO); + } +} +#define CLOSE_ALL_FDS() close_all_fds() + +#include -- cgit 1.4.1