Date: Fri, 10 Jun 2016 18:02:52 +0000 (UTC) From: Garrett Cooper <ngie@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r301803 - stable/10/usr.sbin/rtadvd Message-ID: <201606101802.u5AI2qYm022033@repo.freebsd.org>
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Author: ngie Date: Fri Jun 10 18:02:51 2016 New Revision: 301803 URL: https://svnweb.freebsd.org/changeset/base/301803 Log: MFC r299507: r299507 (by cem): rtadvd(8): Fix a typo in full msg receive logic Check against the size of the struct, not the pointer. Previously, a message with a cm_len between 9 and 23 (inclusive) could cause int msglen to underflow and read(2) to be invoked with msglen size (implicitly cast to signed), overrunning the caller-provided buffer. All users of cm_recv() supply a stack buffer. On the other hand, the rtadvd control socket appears to only be writable by the owner, who is probably root. While here, correct some types to be size_t or ssize_t. CID: 1008477 Security: unix socket remotes may overflow stack in rtadvd Modified: stable/10/usr.sbin/rtadvd/control.c Directory Properties: stable/10/ (props changed) Modified: stable/10/usr.sbin/rtadvd/control.c ============================================================================== --- stable/10/usr.sbin/rtadvd/control.c Fri Jun 10 17:59:30 2016 (r301802) +++ stable/10/usr.sbin/rtadvd/control.c Fri Jun 10 18:02:51 2016 (r301803) @@ -59,7 +59,7 @@ int cm_recv(int fd, char *buf) { - int n; + ssize_t n; struct ctrl_msg_hdr *cm; char *msg; struct pollfd pfds[1]; @@ -98,7 +98,7 @@ cm_recv(int fd, char *buf) } } - if (n != sizeof(*cm)) { + if (n != (ssize_t)sizeof(*cm)) { syslog(LOG_WARNING, "<%s> received a too small message.", __func__); goto cm_recv_err; @@ -123,11 +123,11 @@ cm_recv(int fd, char *buf) "<%s> ctrl msg received: type=%d", __func__, cm->cm_type); - if (cm->cm_len > sizeof(cm)) { - int msglen = cm->cm_len - sizeof(*cm); + if (cm->cm_len > sizeof(*cm)) { + size_t msglen = cm->cm_len - sizeof(*cm); syslog(LOG_DEBUG, - "<%s> ctrl msg has payload (len=%d)", __func__, + "<%s> ctrl msg has payload (len=%zu)", __func__, msglen); for (;;) { @@ -153,7 +153,7 @@ cm_recv(int fd, char *buf) } break; } - if (n != msglen) { + if (n != (ssize_t)msglen) { syslog(LOG_WARNING, "<%s> payload size mismatch.", __func__); goto cm_recv_err;
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