Commit 8f30d2a6 authored by Yossi Gottlieb's avatar Yossi Gottlieb Committed by Oran Agra
Browse files

Fix issue of listen before chmod on Unix sockets (CVE-2023-45145)

Before this commit, Unix socket setup performed chmod(2) on the socket
file after calling listen(2). Depending on what umask is used, this
could leave the file with the wrong permissions for a short period of
time. As a result, another process could exploit this race condition and
establish a connection that would otherwise not be possible.

We now make sure the socket permissions are set up prior to calling
listen(2).

(cherry picked from commit a11b3bc34a054818f2ac70e50adfc542ca1cba42)
(cherry picked from commit 3ca02a0c541e019d77014424e207123160520cec)
parent 24c0bf5c
......@@ -397,13 +397,16 @@ int anetUnixGenericConnect(char *err, const char *path, int flags)
return s;
}
static int anetListen(char *err, int s, struct sockaddr *sa, socklen_t len, int backlog) {
static int anetListen(char *err, int s, struct sockaddr *sa, socklen_t len, int backlog, mode_t perm) {
if (bind(s,sa,len) == -1) {
anetSetError(err, "bind: %s", strerror(errno));
close(s);
return ANET_ERR;
}
if (sa->sa_family == AF_LOCAL && perm)
chmod(((struct sockaddr_un *) sa)->sun_path, perm);
if (listen(s, backlog) == -1) {
anetSetError(err, "listen: %s", strerror(errno));
close(s);
......@@ -447,7 +450,7 @@ static int _anetTcpServer(char *err, int port, char *bindaddr, int af, int backl
if (af == AF_INET6 && anetV6Only(err,s) == ANET_ERR) goto error;
if (anetSetReuseAddr(err,s) == ANET_ERR) goto error;
if (anetListen(err,s,p->ai_addr,p->ai_addrlen,backlog) == ANET_ERR) s = ANET_ERR;
if (anetListen(err,s,p->ai_addr,p->ai_addrlen,backlog,0) == ANET_ERR) s = ANET_ERR;
goto end;
}
if (p == NULL) {
......@@ -484,10 +487,8 @@ int anetUnixServer(char *err, char *path, mode_t perm, int backlog)
memset(&sa,0,sizeof(sa));
sa.sun_family = AF_LOCAL;
strncpy(sa.sun_path,path,sizeof(sa.sun_path)-1);
if (anetListen(err,s,(struct sockaddr*)&sa,sizeof(sa),backlog) == ANET_ERR)
if (anetListen(err,s,(struct sockaddr*)&sa,sizeof(sa),backlog,perm) == ANET_ERR)
return ANET_ERR;
if (perm)
chmod(sa.sun_path, perm);
return s;
}
......
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