This is a note to let you know that I've just added the patch titled
netfilter: complete validation of user input
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
netfilter-complete-validation-of-user-input.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ae6ff91c02b1f1f389a9dd1aaa21c7ca93733f2b
Author: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Tue Apr 9 12:07:41 2024 +0000
netfilter: complete validation of user input
[ Upstream commit 65acf6e0501ac8880a4f73980d01b5d27648b956 ]
In my recent commit, I missed that do_replace() handlers
use copy_from_sockptr() (which I fixed), followed
by unsafe copy_from_sockptr_offset() calls.
In all functions, we can perform the @optlen validation
before even calling xt_alloc_table_info() with the following
check:
if ((u64)optlen < (u64)tmp.size + sizeof(tmp))
return -EINVAL;
Fixes: 0c83842df40f ("netfilter: validate user input for expected length")
Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Reviewed-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240409120741.3538135-1-edumazet@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index b150c9929b12e..14365b20f1c5c 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -966,6 +966,8 @@ static int do_replace(struct net *net, sockptr_t arg, unsigned int len)
return -ENOMEM;
if (tmp.num_counters == 0)
return -EINVAL;
+ if ((u64)len < (u64)tmp.size + sizeof(tmp))
+ return -EINVAL;
tmp.name[sizeof(tmp.name)-1] = 0;
@@ -1266,6 +1268,8 @@ static int compat_do_replace(struct net *net, sockptr_t arg, unsigned int len)
return -ENOMEM;
if (tmp.num_counters == 0)
return -EINVAL;
+ if ((u64)len < (u64)tmp.size + sizeof(tmp))
+ return -EINVAL;
tmp.name[sizeof(tmp.name)-1] = 0;
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 1f365e28e316c..a6208efcfccfc 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -1120,6 +1120,8 @@ do_replace(struct net *net, sockptr_t arg, unsigned int len)
return -ENOMEM;
if (tmp.num_counters == 0)
return -EINVAL;
+ if ((u64)len < (u64)tmp.size + sizeof(tmp))
+ return -EINVAL;
tmp.name[sizeof(tmp.name)-1] = 0;
@@ -1506,6 +1508,8 @@ compat_do_replace(struct net *net, sockptr_t arg, unsigned int len)
return -ENOMEM;
if (tmp.num_counters == 0)
return -EINVAL;
+ if ((u64)len < (u64)tmp.size + sizeof(tmp))
+ return -EINVAL;
tmp.name[sizeof(tmp.name)-1] = 0;
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index 37a2b3301e423..b844e519da1b4 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -1137,6 +1137,8 @@ do_replace(struct net *net, sockptr_t arg, unsigned int len)
return -ENOMEM;
if (tmp.num_counters == 0)
return -EINVAL;
+ if ((u64)len < (u64)tmp.size + sizeof(tmp))
+ return -EINVAL;
tmp.name[sizeof(tmp.name)-1] = 0;
@@ -1515,6 +1517,8 @@ compat_do_replace(struct net *net, sockptr_t arg, unsigned int len)
return -ENOMEM;
if (tmp.num_counters == 0)
return -EINVAL;
+ if ((u64)len < (u64)tmp.size + sizeof(tmp))
+ return -EINVAL;
tmp.name[sizeof(tmp.name)-1] = 0;
