From d2a822fe3958e1daca228d45253497e7216afad3 Mon Sep 17 00:00:00 2001 From: nekral-guest Date: Fri, 17 Apr 2009 21:25:30 +0000 Subject: [PATCH] * libmisc/utmp.c: Do not trust the current utmp entry's ut_line. Always set ut_line based on ttyname(0). --- ChangeLog | 2 ++ libmisc/utmp.c | 26 +++++++++++++++----------- 2 files changed, 17 insertions(+), 11 deletions(-) diff --git a/ChangeLog b/ChangeLog index 9bd3f942..0d5e4141 100644 --- a/ChangeLog +++ b/ChangeLog @@ -2,6 +2,8 @@ * NEWS, src/login.c: Do not trust the current utmp entry's ut_line to set PAM_TTY. + * libmisc/utmp.c: Do not trust the current utmp entry's ut_line. + Always set ut_line based on ttyname(0). 2009-04-15 Nicolas François diff --git a/libmisc/utmp.c b/libmisc/utmp.c index 5218a1e3..409a16d6 100644 --- a/libmisc/utmp.c +++ b/libmisc/utmp.c @@ -113,12 +113,22 @@ void checkutmp (bool picky) && ( (LOGIN_PROCESS == ut->ut_type) || (USER_PROCESS == ut->ut_type)) /* A process may have failed to close an entry - * Check if this entry refers to this tty */ + * Check if this entry refers to the current tty */ && is_my_tty (ut->ut_line)) { break; } } + /* We cannot trust the ut_line field. Prepare the new value. */ + line = ttyname (0); + if (NULL == line) { + (void) puts (NO_TTY); + exit (EXIT_FAILURE); + } + if (strncmp (line, "/dev/", 5) == 0) { + line += 5; + } + /* If there is one, just use it, otherwise create a new one. */ if (NULL != ut) { utent = *ut; @@ -127,23 +137,17 @@ void checkutmp (bool picky) (void) puts (NO_UTENT); exit (EXIT_FAILURE); } - line = ttyname (0); - if (NULL == line) { - (void) puts (NO_TTY); - exit (EXIT_FAILURE); - } - if (strncmp (line, "/dev/", 5) == 0) { - line += 5; - } memset ((void *) &utent, 0, sizeof utent); utent.ut_type = LOGIN_PROCESS; utent.ut_pid = pid; - strncpy (utent.ut_line, line, sizeof utent.ut_line); /* XXX - assumes /dev/tty?? or /dev/pts/?? */ - strncpy (utent.ut_id, utent.ut_line + 3, sizeof utent.ut_id); + strncpy (utent.ut_id, line + 3, sizeof utent.ut_id); strcpy (utent.ut_user, "LOGIN"); utent.ut_time = time (NULL); } + + /* Sanitize / set the ut_line field */ + strncpy (utent.ut_line, line, sizeof utent.ut_line); } #elif defined(LOGIN_PROCESS) -- 2.40.0