diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-05-14 11:11:44 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-05-18 17:06:57 -0700 |
| commit | 6ff8315a4df67bfad96cffc406f91ceb6df70cde (patch) | |
| tree | fdbf10338b5ee6ccccf4994fe8503ff658b54a8a | |
| parent | 62b68367b74b2456ee68deafab047067a6acae67 (diff) | |
nf_conntrack: avoid kernel pointer value leak in slab name
commit 31b0b385f69d8d5491a4bca288e25e63f1d945d0 upstream.
The slab name ends up being visible in the directory structure under
/sys, and even if you don't have access rights to the file you can see
the filenames.
Just use a 64-bit counter instead of the pointer to the 'net' structure
to generate a unique name.
This code will go away in 4.7 when the conntrack code moves to a single
kmemcache, but this is the backportable simple solution to avoiding
leaking kernel pointers to user space.
Fixes: 5b3501faa874 ("netfilter: nf_conntrack: per netns nf_conntrack_cachep")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/netfilter/nf_conntrack_core.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 3cb3cb831591..86a3c6f0c871 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -1757,6 +1757,7 @@ void nf_conntrack_init_end(void) int nf_conntrack_init_net(struct net *net) { + static atomic64_t unique_id; int ret = -ENOMEM; int cpu; @@ -1779,7 +1780,8 @@ int nf_conntrack_init_net(struct net *net) if (!net->ct.stat) goto err_pcpu_lists; - net->ct.slabname = kasprintf(GFP_KERNEL, "nf_conntrack_%p", net); + net->ct.slabname = kasprintf(GFP_KERNEL, "nf_conntrack_%llu", + (u64)atomic64_inc_return(&unique_id)); if (!net->ct.slabname) goto err_slabname; |