This is a note to let you know that I've just added the patch titled
nf_conntrack: avoid kernel pointer value leak in slab name
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
nf_conntrack-avoid-kernel-pointer-value-leak-in-slab-name.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 31b0b385f69d8d5491a4bca288e25e63f1d945d0 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Date: Sat, 14 May 2016 11:11:44 -0700
Subject: nf_conntrack: avoid kernel pointer value leak in slab name
From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxxxxxxx>
Acked-by: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/netfilter/nf_conntrack_core.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- 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 *ne
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;
Patches currently in stable-queue which might be from torvalds@xxxxxxxxxxxxxxxxxxxx are
queue-4.4/nf_conntrack-avoid-kernel-pointer-value-leak-in-slab-name.patch
queue-4.4/ocfs2-fix-posix_acl_create-deadlock.patch
queue-4.4/ocfs2-revert-using-ocfs2_acl_chmod-to-avoid-inode-cluster-lock-hang.patch
queue-4.4/perf-core-disable-the-event-on-a-truncated-aux-record.patch
queue-4.4/bpf-fix-double-fdput-in-replace_map_fd_with_map_ptr.patch
queue-4.4/zsmalloc-fix-zs_can_compact-integer-overflow.patch
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