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authorLinus Torvalds <torvalds@linux-foundation.org>2016-05-14 11:11:44 -0700
committerDavid S. Miller <davem@davemloft.net>2016-05-14 15:04:43 -0400
commit31b0b385f69d8d5491a4bca288e25e63f1d945d0 (patch)
treedcfd83aac04a069512c7188769a7fdaa03bef183
parentb91506586206140154b0b44cccf88c8cc0a4dca5 (diff)
downloadlinux-31b0b385f69d8d5491a4bca288e25e63f1d945d0.tar.gz
nf_conntrack: avoid kernel pointer value leak in slab name
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>
-rw-r--r--net/netfilter/nf_conntrack_core.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 895d11dced3c..e27fd17c6743 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1778,6 +1778,7 @@ void nf_conntrack_init_end(void)
int nf_conntrack_init_net(struct net *net)
{
+ static atomic64_t unique_id;
int ret = -ENOMEM;
int cpu;
@@ -1800,7 +1801,8 @@ 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;