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: Vlad Yasevich <vladislav.yasevich@xxxxxx>
Signed-off-by: Xi Wang <xi.wang@xxxxxxxxx>
---
include/net/sctp/structs.h | 4 ++++
net/sctp/associola.c | 2 +-
net/sctp/protocol.c | 3 +++
net/sctp/socket.c | 2 --
net/sctp/sysctl.c | 13 +++++++++++++
5 files changed, 21 insertions(+), 3 deletions(-)
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index e90e7a9..a15432da 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -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 {
diff --git a/net/sctp/associola.c b/net/sctp/associola.c
index 152b5b3..acd2edb 100644
--- a/net/sctp/associola.c
+++ b/net/sctp/associola.c
@@ -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)
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 61b9fca..6f6ad86 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -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);
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 13bf5fc..54a7cd2 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -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;
}
diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c
index 6b39529..60ffbd0 100644
--- a/net/sctp/sysctl.c
+++ b/net/sctp/sysctl.c
@@ -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 */ }
};
--
1.7.5.4
--
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