diff mbox series

[net] netfilter: complete validation of user input

Message ID 20240409120741.3538135-1-edumazet@google.com (mailing list archive)
State Accepted
Commit 65acf6e0501ac8880a4f73980d01b5d27648b956
Delegated to: Netdev Maintainers
Headers show
Series [net] netfilter: complete validation of user input | expand

Checks

Context Check Description
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 954 this patch: 954
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 1 maintainers not CCed: dsahern@kernel.org
netdev/build_clang success Errors and warnings before: 953 this patch: 953
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 971 this patch: 971
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 48 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-04-10--06-00 (tests: 962)

Commit Message

Eric Dumazet April 9, 2024, 12:07 p.m. UTC 
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@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 net/ipv4/netfilter/arp_tables.c | 4 ++++
 net/ipv4/netfilter/ip_tables.c  | 4 ++++
 net/ipv6/netfilter/ip6_tables.c | 4 ++++
 3 files changed, 12 insertions(+)

Comments

Pablo Neira Ayuso April 10, 2024, 9:23 a.m. UTC | #1 
On Tue, Apr 09, 2024 at 12:07:41PM +0000, Eric Dumazet wrote:
> 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.

I forgot too to git grep away from net/netfilter/ folder for some
reason.

> 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;

Thanks for this fix.

> Fixes: 0c83842df40f ("netfilter: validate user input for expected length")
> Reported-by: syzbot <syzkaller@googlegroups.com>

Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org>

> Signed-off-by: Eric Dumazet <edumazet@google.com>
> ---
>  net/ipv4/netfilter/arp_tables.c | 4 ++++
>  net/ipv4/netfilter/ip_tables.c  | 4 ++++
>  net/ipv6/netfilter/ip6_tables.c | 4 ++++
>  3 files changed, 12 insertions(+)
> 
> diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
> index b150c9929b12e86219a55c77da480e0c538b3449..14365b20f1c5c09964dd7024060116737f22cb63 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 487670759578168c5ff53bce6642898fc41936b3..fe89a056eb06c43743b2d7449e59f4e9360ba223 100644
> --- a/net/ipv4/netfilter/ip_tables.c
> +++ b/net/ipv4/netfilter/ip_tables.c
> @@ -1118,6 +1118,8 @@ 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;
>  
> @@ -1504,6 +1506,8 @@ 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 636b360311c5365fba2330f6ca2f7f1b6dd1363e..131f7bb2110d3a08244c6da40ff9be45a2be711b 100644
> --- a/net/ipv6/netfilter/ip6_tables.c
> +++ b/net/ipv6/netfilter/ip6_tables.c
> @@ -1135,6 +1135,8 @@ 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;
>  
> @@ -1513,6 +1515,8 @@ 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;
>  
> -- 
> 2.44.0.478.gd926399ef9-goog
>
patchwork-bot+netdevbpf@kernel.org April 11, 2024, 2:50 a.m. UTC | #2 
Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Tue,  9 Apr 2024 12:07:41 +0000 you wrote:
> 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:
> 
> [...]

Here is the summary with links:
  - [net] netfilter: complete validation of user input
    https://git.kernel.org/netdev/net/c/65acf6e0501a

You are awesome, thank you!
diff mbox series

Patch

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index b150c9929b12e86219a55c77da480e0c538b3449..14365b20f1c5c09964dd7024060116737f22cb63 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 487670759578168c5ff53bce6642898fc41936b3..fe89a056eb06c43743b2d7449e59f4e9360ba223 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -1118,6 +1118,8 @@  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;
 
@@ -1504,6 +1506,8 @@  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 636b360311c5365fba2330f6ca2f7f1b6dd1363e..131f7bb2110d3a08244c6da40ff9be45a2be711b 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -1135,6 +1135,8 @@  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;
 
@@ -1513,6 +1515,8 @@  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;