Date: Fri, 19 Jul 2019 15:37:29 +0000 (UTC) From: Philip Paeps <philip@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r350139 - stable/12/contrib/telnet/telnet Message-ID: <201907191537.x6JFbTwK069730@repo.freebsd.org>
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Author: philip Date: Fri Jul 19 15:37:29 2019 New Revision: 350139 URL: https://svnweb.freebsd.org/changeset/base/350139 Log: MFC r349890: telnet: fix a couple of snprintf() buffer overflows Obtained from: Juniper Networks MFC r349896: telnet: fix minor style violationo While here also fix a very unlikely NULL pointer dereference. Submitted by: Shawn Webb <shawn.webb@hardenedbsd.org> Modified: stable/12/contrib/telnet/telnet/commands.c stable/12/contrib/telnet/telnet/telnet.c stable/12/contrib/telnet/telnet/utilities.c Directory Properties: stable/12/ (props changed) Modified: stable/12/contrib/telnet/telnet/commands.c ============================================================================== --- stable/12/contrib/telnet/telnet/commands.c Fri Jul 19 15:24:08 2019 (r350138) +++ stable/12/contrib/telnet/telnet/commands.c Fri Jul 19 15:37:29 2019 (r350139) @@ -45,6 +45,7 @@ __FBSDID("$FreeBSD$"); #include <sys/socket.h> #include <netinet/in.h> +#include <assert.h> #include <ctype.h> #include <err.h> #include <errno.h> @@ -1654,11 +1655,14 @@ env_init(void) || (strncmp((char *)ep->value, "unix:", 5) == 0))) { char hbuf[256+1]; char *cp2 = strchr((char *)ep->value, ':'); + size_t buflen; - gethostname(hbuf, 256); - hbuf[256] = '\0'; - cp = (char *)malloc(strlen(hbuf) + strlen(cp2) + 1); - sprintf((char *)cp, "%s%s", hbuf, cp2); + gethostname(hbuf, sizeof(hbuf)); + hbuf[sizeof(hbuf)-1] = '\0'; + buflen = strlen(hbuf) + strlen(cp2) + 1; + cp = (char *)malloc(sizeof(char)*buflen); + assert(cp != NULL); + snprintf((char *)cp, buflen, "%s%s", hbuf, cp2); free(ep->value); ep->value = (unsigned char *)cp; } Modified: stable/12/contrib/telnet/telnet/telnet.c ============================================================================== --- stable/12/contrib/telnet/telnet/telnet.c Fri Jul 19 15:24:08 2019 (r350138) +++ stable/12/contrib/telnet/telnet/telnet.c Fri Jul 19 15:37:29 2019 (r350139) @@ -785,7 +785,7 @@ suboption(void) name = gettermname(); len = strlen(name) + 4 + 2; if (len < NETROOM()) { - sprintf(temp, "%c%c%c%c%s%c%c", IAC, SB, TELOPT_TTYPE, + snprintf(temp, sizeof(temp), "%c%c%c%c%s%c%c", IAC, SB, TELOPT_TTYPE, TELQUAL_IS, name, IAC, SE); ring_supply_data(&netoring, temp, len); printsub('>', &temp[2], len-2); @@ -807,7 +807,7 @@ suboption(void) TerminalSpeeds(&ispeed, &ospeed); - sprintf((char *)temp, "%c%c%c%c%ld,%ld%c%c", IAC, SB, TELOPT_TSPEED, + snprintf((char *)temp, sizeof(temp), "%c%c%c%c%ld,%ld%c%c", IAC, SB, TELOPT_TSPEED, TELQUAL_IS, ospeed, ispeed, IAC, SE); len = strlen((char *)temp+4) + 4; /* temp[3] is 0 ... */ Modified: stable/12/contrib/telnet/telnet/utilities.c ============================================================================== --- stable/12/contrib/telnet/telnet/utilities.c Fri Jul 19 15:24:08 2019 (r350138) +++ stable/12/contrib/telnet/telnet/utilities.c Fri Jul 19 15:37:29 2019 (r350139) @@ -629,7 +629,7 @@ printsub(char direction, unsigned char *pointer, int l } { char tbuf[64]; - sprintf(tbuf, "%s%s%s%s%s", + snprintf(tbuf, sizeof(tbuf), "%s%s%s%s%s", pointer[2]&MODE_EDIT ? "|EDIT" : "", pointer[2]&MODE_TRAPSIG ? "|TRAPSIG" : "", pointer[2]&MODE_SOFT_TAB ? "|SOFT_TAB" : "",
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