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authorLinus Torvalds <torvalds@linux-foundation.org>2016-05-14 11:11:44 -0700
committerSasha Levin <sasha.levin@oracle.com>2016-05-17 13:43:15 -0400
commit8de861b16d946b7c0ce246fcbb65d550c357c65c (patch)
parent631598a5c08505c92348b3907824072d0c1000ab (diff)
nf_conntrack: avoid kernel pointer value leak in slab name
[ Upstream commit 31b0b385f69d8d5491a4bca288e25e63f1d945d0 ] 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> Cc: stable@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
1 files changed, 3 insertions, 1 deletions
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 13fad8668f83..bc3f791845aa 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1735,6 +1735,7 @@ void nf_conntrack_init_end(void)
int nf_conntrack_init_net(struct net *net)
+ static atomic64_t unique_id;
int ret = -ENOMEM;
int cpu;
@@ -1758,7 +1759,8 @@ 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;