Commit 2692ba61 authored by Xi Wang's avatar Xi Wang Committed by David S. Miller
Browse files

sctp: fix incorrect overflow check on autoclose 



Commit 8ffd3208 voids the previous patches f6778aab and 810c0719 for
limiting the autoclose value.  If userspace passes in -1 on 32-bit
platform, the overflow check didn't work and autoclose would be set
to 0xffffffff.

This patch defines a max_autoclose (in seconds) for limiting the value
and exposes it through sysctl, with the following intentions.

1) Avoid overflowing autoclose * HZ.

2) Keep the default autoclose bound consistent across 32- and 64-bit
   platforms (INT_MAX / HZ in this patch).

3) Keep the autoclose value consistent between setsockopt() and
   getsockopt() calls.

Suggested-by: default avatarVlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: default avatarXi Wang <xi.wang@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2ca6cf06

include/net/sctp/structs.h

+4 −0
Original line number Diff line number Diff line
@@ -241,6 +241,9 @@ extern struct sctp_globals { 
	 * bits is an indicator of when to send and window update SACK.

	 */

	int rwnd_update_shift;



	/* Threshold for autoclose timeout, in seconds. */

	unsigned long max_autoclose;

} sctp_globals;



#define sctp_rto_initial		(sctp_globals.rto_initial)
@@ -281,6 +284,7 @@ extern struct sctp_globals { 
#define sctp_auth_enable		(sctp_globals.auth_enable)

#define sctp_checksum_disable		(sctp_globals.checksum_disable)

#define sctp_rwnd_upd_shift		(sctp_globals.rwnd_update_shift)

#define sctp_max_autoclose		(sctp_globals.max_autoclose)



/* SCTP Socket type: UDP or TCP style. */

typedef enum {

net/sctp/associola.c

+1 −1
Original line number Diff line number Diff line
@@ -173,7 +173,7 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a 
	asoc->timeouts[SCTP_EVENT_TIMEOUT_HEARTBEAT] = 0;

	asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = asoc->sackdelay;

	asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] =

		(unsigned long)sp->autoclose * HZ;

		min_t(unsigned long, sp->autoclose, sctp_max_autoclose) * HZ;



	/* Initializes the timers */

	for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i)

net/sctp/protocol.c

+3 −0
Original line number Diff line number Diff line
@@ -1285,6 +1285,9 @@ SCTP_STATIC __init int sctp_init(void) 
	sctp_max_instreams    		= SCTP_DEFAULT_INSTREAMS;

	sctp_max_outstreams   		= SCTP_DEFAULT_OUTSTREAMS;



	/* Initialize maximum autoclose timeout. */

	sctp_max_autoclose		= INT_MAX / HZ;



	/* Initialize handle used for association ids. */

	idr_init(&sctp_assocs_id);

net/sctp/socket.c

+0 −2
Original line number Diff line number Diff line
@@ -2200,8 +2200,6 @@ static int sctp_setsockopt_autoclose(struct sock *sk, char __user *optval, 
		return -EINVAL;

	if (copy_from_user(&sp->autoclose, optval, optlen))

		return -EFAULT;

	/* make sure it won't exceed MAX_SCHEDULE_TIMEOUT */

	sp->autoclose = min_t(long, sp->autoclose, MAX_SCHEDULE_TIMEOUT / HZ);



	return 0;

}

net/sctp/sysctl.c

+13 −0
Original line number Diff line number Diff line
@@ -53,6 +53,10 @@ static int sack_timer_min = 1; 
static int sack_timer_max = 500;

static int addr_scope_max = 3; /* check sctp_scope_policy_t in include/net/sctp/constants.h for max entries */

static int rwnd_scale_max = 16;

static unsigned long max_autoclose_min = 0;

static unsigned long max_autoclose_max =

	(MAX_SCHEDULE_TIMEOUT / HZ > UINT_MAX)

	? UINT_MAX : MAX_SCHEDULE_TIMEOUT / HZ;



extern long sysctl_sctp_mem[3];

extern int sysctl_sctp_rmem[3];
@@ -258,6 +262,15 @@ static ctl_table sctp_table[] = { 
		.extra1		= &one,

		.extra2		= &rwnd_scale_max,

	},

	{

		.procname	= "max_autoclose",

		.data		= &sctp_max_autoclose,

		.maxlen		= sizeof(unsigned long),

		.mode		= 0644,

		.proc_handler	= &proc_doulongvec_minmax,

		.extra1		= &max_autoclose_min,

		.extra2		= &max_autoclose_max,

	},



	{ /* sentinel */ }

};

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