Commit 65acf6e0 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski

netfilter: complete validation of user input

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: 0c83842d ("netfilter: validate user input for expected length")
Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
Link: https://lore.kernel.org/r/20240409120741.3538135-1-edumazet@google.comSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 97e176fc
...@@ -966,6 +966,8 @@ static int do_replace(struct net *net, sockptr_t arg, unsigned int len) ...@@ -966,6 +966,8 @@ static int do_replace(struct net *net, sockptr_t arg, unsigned int len)
return -ENOMEM; return -ENOMEM;
if (tmp.num_counters == 0) if (tmp.num_counters == 0)
return -EINVAL; return -EINVAL;
if ((u64)len < (u64)tmp.size + sizeof(tmp))
return -EINVAL;
tmp.name[sizeof(tmp.name)-1] = 0; 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) ...@@ -1266,6 +1268,8 @@ static int compat_do_replace(struct net *net, sockptr_t arg, unsigned int len)
return -ENOMEM; return -ENOMEM;
if (tmp.num_counters == 0) if (tmp.num_counters == 0)
return -EINVAL; return -EINVAL;
if ((u64)len < (u64)tmp.size + sizeof(tmp))
return -EINVAL;
tmp.name[sizeof(tmp.name)-1] = 0; tmp.name[sizeof(tmp.name)-1] = 0;
......
...@@ -1118,6 +1118,8 @@ do_replace(struct net *net, sockptr_t arg, unsigned int len) ...@@ -1118,6 +1118,8 @@ do_replace(struct net *net, sockptr_t arg, unsigned int len)
return -ENOMEM; return -ENOMEM;
if (tmp.num_counters == 0) if (tmp.num_counters == 0)
return -EINVAL; return -EINVAL;
if ((u64)len < (u64)tmp.size + sizeof(tmp))
return -EINVAL;
tmp.name[sizeof(tmp.name)-1] = 0; tmp.name[sizeof(tmp.name)-1] = 0;
...@@ -1504,6 +1506,8 @@ compat_do_replace(struct net *net, sockptr_t arg, unsigned int len) ...@@ -1504,6 +1506,8 @@ compat_do_replace(struct net *net, sockptr_t arg, unsigned int len)
return -ENOMEM; return -ENOMEM;
if (tmp.num_counters == 0) if (tmp.num_counters == 0)
return -EINVAL; return -EINVAL;
if ((u64)len < (u64)tmp.size + sizeof(tmp))
return -EINVAL;
tmp.name[sizeof(tmp.name)-1] = 0; tmp.name[sizeof(tmp.name)-1] = 0;
......
...@@ -1135,6 +1135,8 @@ do_replace(struct net *net, sockptr_t arg, unsigned int len) ...@@ -1135,6 +1135,8 @@ do_replace(struct net *net, sockptr_t arg, unsigned int len)
return -ENOMEM; return -ENOMEM;
if (tmp.num_counters == 0) if (tmp.num_counters == 0)
return -EINVAL; return -EINVAL;
if ((u64)len < (u64)tmp.size + sizeof(tmp))
return -EINVAL;
tmp.name[sizeof(tmp.name)-1] = 0; tmp.name[sizeof(tmp.name)-1] = 0;
...@@ -1513,6 +1515,8 @@ compat_do_replace(struct net *net, sockptr_t arg, unsigned int len) ...@@ -1513,6 +1515,8 @@ compat_do_replace(struct net *net, sockptr_t arg, unsigned int len)
return -ENOMEM; return -ENOMEM;
if (tmp.num_counters == 0) if (tmp.num_counters == 0)
return -EINVAL; return -EINVAL;
if ((u64)len < (u64)tmp.size + sizeof(tmp))
return -EINVAL;
tmp.name[sizeof(tmp.name)-1] = 0; tmp.name[sizeof(tmp.name)-1] = 0;
......
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