The range calculation for choosing the random reserved port will panic
with divide-by-zero when min_resvport == max_resvport, a range of one
port, not zero.
In addition, the sysctl and kernel module parameters only limit the
min_resvport and max_resvport values to the entire range of allowed
ports, so the min and max may become inverted, with max_resvport
set to a value lower than min_resvport.
These patches address both issues by correcting the port range
calculation and setting the min_resvport/max_resvport limits
to be dependent on each other.
Signed-off-by: Frank Sorenson <[email protected]>
[PATCH 1/3] sunrpc: Fix reserved port range calculation
[PATCH 2/3] sunrpc: Prevent resvport min/max inversion via sysctl
[PATCH 3/3] sunrpc: Prevent resvport min/max inversion via sysfs and
The range calculation for choosing the random reserved port will panic
with divide-by-zero when min_resvport == max_resvport, a range of one
port, not zero.
Fix the reserved port range calculation by adding one to the difference.
Signed-off-by: Frank Sorenson <[email protected]>
---
net/sunrpc/xprtsock.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 7e2b2fa..1adda71 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -1714,7 +1714,7 @@ static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
static unsigned short xs_get_random_port(void)
{
- unsigned short range = xprt_max_resvport - xprt_min_resvport;
+ unsigned short range = xprt_max_resvport - xprt_min_resvport + 1;
unsigned short rand = (unsigned short) prandom_u32() % range;
return rand + xprt_min_resvport;
}
--
2.5.5
The current min/max resvport settings are independently limited
by the entire range of allowed ports, so max_resvport can be
set to a port lower than min_resvport.
Prevent inversion of min/max values when set through sysctl by
setting the limits dependent on each other.
Signed-off-by: Frank Sorenson <[email protected]>
---
net/sunrpc/xprtsock.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 1adda71..2674309 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -124,7 +124,7 @@ static struct ctl_table xs_tunables_table[] = {
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &xprt_min_resvport_limit,
- .extra2 = &xprt_max_resvport_limit
+ .extra2 = &xprt_max_resvport
},
{
.procname = "max_resvport",
@@ -132,7 +132,7 @@ static struct ctl_table xs_tunables_table[] = {
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
- .extra1 = &xprt_min_resvport_limit,
+ .extra1 = &xprt_min_resvport,
.extra2 = &xprt_max_resvport_limit
},
{
--
2.5.5
The current min/max resvport settings are independently limited
by the entire range of allowed ports, so max_resvport can be
set to a port lower than min_resvport.
Prevent inversion of min/max values when set through sysfs and
module parameter by setting the limits dependent on each other.
Signed-off-by: Frank Sorenson <[email protected]>
---
net/sunrpc/xprtsock.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 2674309..83e6f33 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -3153,8 +3153,12 @@ static int param_set_uint_minmax(const char *val,
static int param_set_portnr(const char *val, const struct kernel_param *kp)
{
- return param_set_uint_minmax(val, kp,
+ if (kp->arg == &xprt_min_resvport)
+ return param_set_uint_minmax(val, kp,
RPC_MIN_RESVPORT,
+ xprt_max_resvport);
+ return param_set_uint_minmax(val, kp,
+ xprt_min_resvport,
RPC_MAX_RESVPORT);
}
--
2.5.5