From 653dc1e61cd9d4d4921158a2c5dec49962bb9f0a Mon Sep 17 00:00:00 2001 From: Peter Hutterer Date: Wed, 12 Sep 2018 14:46:05 +1000 Subject: Replace strncpy calls with a sane version that always terminates Fixes coverity complaints about potentially unterminated strings Signed-off-by: Peter Hutterer Reviewed-by: Alan Coopersmith --- sessreg.c | 28 ++++++++++++++++++---------- 1 file changed, 18 insertions(+), 10 deletions(-) (limited to 'sessreg.c') diff --git a/sessreg.c b/sessreg.c index 0a8fdb2..7725bcc 100644 --- a/sessreg.c +++ b/sessreg.c @@ -192,6 +192,14 @@ sysnerr (int x, const char *s) return x; } +static void +safe_strncpy(char *dest, const char *src, size_t n) +{ + (void)strncpy(dest, src, n); + if (n > 0) + dest[n - 1] = '\0'; +} + int main (int argc, char **argv) { @@ -406,9 +414,9 @@ main (int argc, char **argv) memset(&ll, 0, sizeof(ll)); ll.ll_time = current_time; if (line) - (void) strncpy (ll.ll_line, line, sizeof (ll.ll_line)); + safe_strncpy (ll.ll_line, line, sizeof (ll.ll_line)); if (host_name) - (void) strncpy (ll.ll_host, host_name, sizeof (ll.ll_host)); + safe_strncpy (ll.ll_host, host_name, sizeof (ll.ll_host)); sysnerr (write (llog, (char *) &ll, sizeof (ll)) == sizeof (ll), "write lastlog entry"); @@ -429,11 +437,11 @@ set_utmp (struct utmp *u, char *line, char *user, char *host, time_t date, int a { memset (u, 0, sizeof (*u)); if (line) - (void) strncpy (u->ut_line, line, sizeof (u->ut_line)); + safe_strncpy (u->ut_line, line, sizeof (u->ut_line)); else memset (u->ut_line, 0, sizeof (u->ut_line)); if (addp && user) - (void) strncpy (u->ut_name, user, sizeof (u->ut_name)); + safe_strncpy (u->ut_name, user, sizeof (u->ut_name)); else memset (u->ut_name, 0, sizeof (u->ut_name)); #ifdef HAVE_STRUCT_UTMP_UT_ID @@ -451,7 +459,7 @@ set_utmp (struct utmp *u, char *line, char *user, char *host, time_t date, int a i -= sizeof (u->ut_id); else i = 0; - (void) strncpy (u->ut_id, line + i, sizeof (u->ut_id)); + safe_strncpy (u->ut_id, line + i, sizeof (u->ut_id)); } else memset (u->ut_id, 0, sizeof (u->ut_id)); #endif @@ -469,7 +477,7 @@ set_utmp (struct utmp *u, char *line, char *user, char *host, time_t date, int a #endif #ifdef HAVE_STRUCT_UTMP_UT_HOST if (addp && host) - (void) strncpy (u->ut_host, host, sizeof (u->ut_host)); + safe_strncpy (u->ut_host, host, sizeof (u->ut_host)); else memset (u->ut_host, 0, sizeof (u->ut_host)); #endif @@ -513,9 +521,9 @@ set_utmpx (struct utmpx *u, const char *line, const char *user, if(strcmp(line, ":0") == 0) (void) strcpy(u->ut_line, "console"); else - (void) strncpy (u->ut_line, line, sizeof (u->ut_line)); + safe_strncpy (u->ut_line, line, sizeof (u->ut_line)); - strncpy(u->ut_host, line, sizeof(u->ut_host)); + safe_strncpy(u->ut_host, line, sizeof(u->ut_host)); #ifdef HAVE_STRUCT_UTMPX_UT_SYSLEN u->ut_syslen = strlen(line); #endif @@ -523,7 +531,7 @@ set_utmpx (struct utmpx *u, const char *line, const char *user, else memset (u->ut_line, 0, sizeof (u->ut_line)); if (addp && user) - (void) strncpy (u->ut_user, user, sizeof (u->ut_user)); + safe_strncpy (u->ut_user, user, sizeof (u->ut_user)); else memset (u->ut_user, 0, sizeof (u->ut_user)); @@ -541,7 +549,7 @@ set_utmpx (struct utmpx *u, const char *line, const char *user, i -= sizeof (u->ut_id); else i = 0; - (void) strncpy (u->ut_id, line + i, sizeof (u->ut_id)); + safe_strncpy (u->ut_id, line + i, sizeof (u->ut_id)); /* make sure there is no entry using identical ut_id */ if (!UtmpxIdOpen(u->ut_id) && addp) { -- cgit v1.2.3