[PATCH net-next v2 0/2] Fix overflow errors in /proc/sys/net/ipv4/neigh/

[PATCH net-next v2 0/2] Fix overflow errors in /proc/sys/net/ipv4/neigh/

[Francesco Fusco]

These two patches fix possible overflow errors in /proc/sys/net/ipv4/neigh/.

Francesco Fusco (2):
  neigh: prevent overflowing params in /proc/sys/net/ipv4/neigh/
  sysctl: range checking in do_proc_dointvec_ms_jiffies_conv

 kernel/sysctl.c      |  6 +++++-
 net/core/neighbour.c | 29 ++++++++++++++++++++++-------
 2 files changed, 27 insertions(+), 8 deletions(-)

-- 
1.8.3.1

[PATCH net-next v2 1/2] neigh: prevent overflowing params in /proc/sys/net/ipv4/neigh/

[Francesco Fusco]

Without this patch, the fields app_solicit, gc_thresh1, gc_thresh2,
gc_thresh3, proxy_qlen, ucast_solicit, mcast_solicit could have
assumed negative values when setting large numbers.

Signed-off-by: Francesco Fusco <ffusco@redhat.com>
---
 net/core/neighbour.c | 29 ++++++++++++++++++++++-------
 1 file changed, 22 insertions(+), 7 deletions(-)

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index b7de821..9232c68 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -2767,6 +2767,7 @@ EXPORT_SYMBOL(neigh_app_ns);
 
 #ifdef CONFIG_SYSCTL
 static int zero;
+static int int_max = INT_MAX;
 static int unres_qlen_max = INT_MAX / SKB_TRUESIZE(ETH_FRAME_LEN);
 
 static int proc_unres_qlen(struct ctl_table *ctl, int write,
@@ -2819,19 +2820,25 @@ static struct neigh_sysctl_table {
 			.procname	= "mcast_solicit",
 			.maxlen		= sizeof(int),
 			.mode		= 0644,
-			.proc_handler	= proc_dointvec,
+			.extra1 	= &zero,
+			.extra2		= &int_max,
+			.proc_handler	= proc_dointvec_minmax,
 		},
 		[NEIGH_VAR_UCAST_PROBE] = {
 			.procname	= "ucast_solicit",
 			.maxlen		= sizeof(int),
 			.mode		= 0644,
-			.proc_handler	= proc_dointvec,
+			.extra1 	= &zero,
+			.extra2		= &int_max,
+			.proc_handler	= proc_dointvec_minmax,
 		},
 		[NEIGH_VAR_APP_PROBE] = {
 			.procname	= "app_solicit",
 			.maxlen		= sizeof(int),
 			.mode		= 0644,
-			.proc_handler	= proc_dointvec,
+			.extra1 	= &zero,
+			.extra2		= &int_max,
+			.proc_handler	= proc_dointvec_minmax,
 		},
 		[NEIGH_VAR_RETRANS_TIME] = {
 			.procname	= "retrans_time",
@@ -2874,7 +2881,9 @@ static struct neigh_sysctl_table {
 			.procname	= "proxy_qlen",
 			.maxlen		= sizeof(int),
 			.mode		= 0644,
-			.proc_handler	= proc_dointvec,
+			.extra1 	= &zero,
+			.extra2		= &int_max,
+			.proc_handler	= proc_dointvec_minmax,
 		},
 		[NEIGH_VAR_ANYCAST_DELAY] = {
 			.procname	= "anycast_delay",
@@ -2916,19 +2925,25 @@ static struct neigh_sysctl_table {
 			.procname	= "gc_thresh1",
 			.maxlen		= sizeof(int),
 			.mode		= 0644,
-			.proc_handler	= proc_dointvec,
+			.extra1 	= &zero,
+			.extra2		= &int_max,
+			.proc_handler	= proc_dointvec_minmax,
 		},
 		[NEIGH_VAR_GC_THRESH2] = {
 			.procname	= "gc_thresh2",
 			.maxlen		= sizeof(int),
 			.mode		= 0644,
-			.proc_handler	= proc_dointvec,
+			.extra1 	= &zero,
+			.extra2		= &int_max,
+			.proc_handler	= proc_dointvec_minmax,
 		},
 		[NEIGH_VAR_GC_THRESH3] = {
 			.procname	= "gc_thresh3",
 			.maxlen		= sizeof(int),
 			.mode		= 0644,
-			.proc_handler	= proc_dointvec,
+			.extra1 	= &zero,
+			.extra2		= &int_max,
+			.proc_handler	= proc_dointvec_minmax,
 		},
 		{},
 	},
-- 
1.8.3.1

[PATCH net-next v2 2/2] sysctl: range checking in do_proc_dointvec_ms_jiffies_conv

[Francesco Fusco]

When (integer) sysctl values are expressed in ms and have to be
represented internally as jiffies. The msecs_to_jiffies function
returns an unsigned long, which gets assigned to the integer.
This patch prevents the value to be assigned if bigger than
INT_MAX, done in a similar way as in cba9f3 ("Range checking in
do_proc_dointvec_(userhz_)jiffies_conv").

Signed-off-by: Francesco Fusco <ffusco@redhat.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: linux-kernel@vger.kernel.org
---
 v1 => v2 
 - fix style suggested by Sergei Shtylyov

 kernel/sysctl.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index ac09d98..07f6fc4 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2346,7 +2346,11 @@ static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
 					    int write, void *data)
 {
 	if (write) {
-		*valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
+		unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
+
+		if (jif > INT_MAX)
+			return 1;
+		*valp = (int)jif;
 	} else {
 		int val = *valp;
 		unsigned long lval;
-- 
1.8.3.1