From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
This patch has been added to the 3.18 stable tree. If you have any
objections, please let us know.
===============
[ 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@xxxxxxxxxxxxxxxxxxxx>
Acked-by: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
---
net/netfilter/nf_conntrack_core.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index c588012..98cd0e7 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1739,6 +1739,7 @@ void nf_conntrack_init_end(void)
int nf_conntrack_init_net(struct net *net)
{
+ static atomic64_t unique_id;
int ret = -ENOMEM;
int cpu;
@@ -1762,7 +1763,8 @@ 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;
--
2.5.0
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