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Before dereferencing intotw() when INP_TIMEWAIT, check for inp_ppcb being

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NULL.  We currently do allow this to happen, but may want to remove that
possibility in the future.  This case can occur when a socket is left
open after TCP wraps up, and the timewait state is recycled.  This will
be cleaned up in the future.

Found by:	Kazuaki Oda <kaakun at highway dot ne dot jp>
MFC after:	3 months
This commit is contained in:
Robert Watson 2006-04-04 12:26:07 +00:00
parent 46587ab898
commit ae0e714308
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=157474
5 changed files with 62 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
sys/netinet/in_pcb.c
View File

@ -322,6 +322,8 @@ in_pcbbind_setup(struct inpcb *inp, struct sockaddr *nam, in_addr_t *laddrp,
laddr = sin->sin_addr;
if (lport) {
struct inpcb *t;
struct tcptw *tw;
/* GROSS */
if (ntohs(lport) <= ipport_reservedhigh &&
ntohs(lport) >= ipport_reservedlow &&
@ -355,10 +357,17 @@ in_pcbbind_setup(struct inpcb *inp, struct sockaddr *nam, in_addr_t *laddrp,
t = in_pcblookup_local(pcbinfo, sin->sin_addr,
lport, prison ? 0 : wild);
if (t && (t->inp_vflag & INP_TIMEWAIT)) {
if ((reuseport & intotw(t)->tw_so_options) == 0)
/*
* XXXRW: If an incpb has had its timewait
* state recycled, we treat the address as
* being in use (for now). This is better
* than a panic, but not desirable.
*/
tw = intotw(inp);
if (tw == NULL ||
(reuseport & tw->tw_so_options) == 0)
return (EADDRINUSE);
} else
if (t &&
} else if (t &&
(reuseport & t->inp_socket->so_options) == 0) {
#if defined(INET6)
if (ntohl(sin->sin_addr.s_addr) !=
@ -950,7 +959,8 @@ in_pcblookup_local(struct inpcbinfo *pcbinfo, struct in_addr laddr,
*/
if ((inp->inp_vflag & INP_TIMEWAIT) != 0) {
tw = intotw(inp);
if (tcp_twrecycleable(tw)) {
if (tw != NULL &&
tcp_twrecycleable(tw)) {
INP_LOCK(inp);
tcp_twclose(tw, 0);
match = NULL;

9
sys/netinet/tcp_input.c
View File

@ -3156,6 +3156,15 @@ tcp_timewait(tw, to, th, m, tlen)
const int isipv6 = 0;
#endif
/*
* XXXRW: Time wait state for inpcb has been recycled, but inpcb is
* still present. This is undesirable, but temporarily necessary
* until we work out how to handle inpcb's who's timewait state has
* been removed.
*/
if (tw == NULL)
goto drop;
/* tcbinfo lock required for tcp_twclose(), tcp_2msl_reset. */
INP_INFO_WLOCK_ASSERT(&tcbinfo);
INP_LOCK_ASSERT(tw->tw_inpcb);

9
sys/netinet/tcp_reass.c
View File

@ -3156,6 +3156,15 @@ tcp_timewait(tw, to, th, m, tlen)
const int isipv6 = 0;
#endif
/*
* XXXRW: Time wait state for inpcb has been recycled, but inpcb is
* still present. This is undesirable, but temporarily necessary
* until we work out how to handle inpcb's who's timewait state has
* been removed.
*/
if (tw == NULL)
goto drop;
/* tcbinfo lock required for tcp_twclose(), tcp_2msl_reset. */
INP_INFO_WLOCK_ASSERT(&tcbinfo);
INP_LOCK_ASSERT(tw->tw_inpcb);

20
sys/netinet/tcp_subr.c
View File

@ -946,10 +946,13 @@ tcp_pcblist(SYSCTL_HANDLER_ARGS)
* TCP state changes, is not quite right, but for
* now, better than nothing.
*/
if (inp->inp_vflag & INP_TIMEWAIT)
error = cr_cansee(req->td->td_ucred,
intotw(inp)->tw_cred);
else
if (inp->inp_vflag & INP_TIMEWAIT) {
if (intotw(inp) != NULL)
error = cr_cansee(req->td->td_ucred,
intotw(inp)->tw_cred);
else
error = EINVAL; /* Skip this inp. */
} else
error = cr_canseesocket(req->td->td_ucred,
inp->inp_socket);
if (error == 0)
@ -2323,8 +2326,15 @@ sysctl_drop(SYSCTL_HANDLER_ARGS)
if (inp != NULL) {
INP_LOCK(inp);
if (inp->inp_vflag & INP_TIMEWAIT) {
/*
* XXXRW: There currently exists a state where an
* inpcb is present, but its timewait state has been
* discarded. For now, don't allow dropping of this
* type of inpcb.
*/
tw = intotw(inp);
tcp_twclose(tw, 0);
if (tw != NULL)
tcp_twclose(tw, 0);
} else if (!(inp->inp_vflag & INP_DROPPED) &&
!(inp->inp_socket->so_options & SO_ACCEPTCONN)) {
tp = intotcpcb(inp);

20
sys/netinet/tcp_timewait.c
View File

@ -946,10 +946,13 @@ tcp_pcblist(SYSCTL_HANDLER_ARGS)
* TCP state changes, is not quite right, but for
* now, better than nothing.
*/
if (inp->inp_vflag & INP_TIMEWAIT)
error = cr_cansee(req->td->td_ucred,
intotw(inp)->tw_cred);
else
if (inp->inp_vflag & INP_TIMEWAIT) {
if (intotw(inp) != NULL)
error = cr_cansee(req->td->td_ucred,
intotw(inp)->tw_cred);
else
error = EINVAL; /* Skip this inp. */
} else
error = cr_canseesocket(req->td->td_ucred,
inp->inp_socket);
if (error == 0)
@ -2323,8 +2326,15 @@ sysctl_drop(SYSCTL_HANDLER_ARGS)
if (inp != NULL) {
INP_LOCK(inp);
if (inp->inp_vflag & INP_TIMEWAIT) {
/*
* XXXRW: There currently exists a state where an
* inpcb is present, but its timewait state has been
* discarded. For now, don't allow dropping of this
* type of inpcb.
*/
tw = intotw(inp);
tcp_twclose(tw, 0);
if (tw != NULL)
tcp_twclose(tw, 0);
} else if (!(inp->inp_vflag & INP_DROPPED) &&
!(inp->inp_socket->so_options & SO_ACCEPTCONN)) {
tp = intotcpcb(inp);