[PATCH] netfilter: x_tables: fix incorrect parameter length before call copy_from_sockptr
From: Edward Adam Davis
Date: Tue Apr 09 2024 - 11:00:47 EST
If len < sizeof(tmp) it will trigger oob, so take the min of them.
Signed-off-by: Edward Adam Davis <eadavis@xxxxxx>
---
net/ipv4/netfilter/arp_tables.c | 4 ++--
net/ipv4/netfilter/ip_tables.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 2407066b0fec..dc9166b48069 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -956,7 +956,7 @@ static int do_replace(struct net *net, sockptr_t arg, unsigned int len)
void *loc_cpu_entry;
struct arpt_entry *iter;
- if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0)
+ if (copy_from_sockptr(&tmp, arg, min_t(unsigned int, sizeof(tmp), len)) != 0)
return -EFAULT;
/* overflow check */
@@ -1254,7 +1254,7 @@ static int compat_do_replace(struct net *net, sockptr_t arg, unsigned int len)
void *loc_cpu_entry;
struct arpt_entry *iter;
- if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0)
+ if (copy_from_sockptr(&tmp, arg, min_t(unsigned int, sizeof(tmp), len)) != 0)
return -EFAULT;
/* overflow check */
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 7da1df4997d0..94a0afd8f94f 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -1108,7 +1108,7 @@ do_replace(struct net *net, sockptr_t arg, unsigned int len)
void *loc_cpu_entry;
struct ipt_entry *iter;
- if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0)
+ if (copy_from_sockptr(&tmp, arg, min_t(unsigned int, sizeof(tmp), len)) != 0)
return -EFAULT;
/* overflow check */
@@ -1492,7 +1492,7 @@ compat_do_replace(struct net *net, sockptr_t arg, unsigned int len)
void *loc_cpu_entry;
struct ipt_entry *iter;
- if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0)
+ if (copy_from_sockptr(&tmp, arg, min_t(unsigned int, sizeof(tmp), len)) != 0)
return -EFAULT;
/* overflow check */
--
2.43.0