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authorWillem de Bruijn <willemb@google.com>2015-01-30 21:29:32 +0300
committerDavid S. Miller <davem@davemloft.net>2015-02-03 05:46:51 +0300
commitb245be1f4db1a0394e4b6eb66059814b46670ac3 (patch)
treee9e4e746bcb24db72ae5a947c7001bab21211a8e /include/net
parent49ca0d8bfaf3bc46d5eef60ce67b00eb195bd392 (diff)
downloadlinux-b245be1f4db1a0394e4b6eb66059814b46670ac3.tar.xz
net-timestamp: no-payload only sysctl
Tx timestamps are looped onto the error queue on top of an skb. This mechanism leaks packet headers to processes unless the no-payload options SOF_TIMESTAMPING_OPT_TSONLY is set. Add a sysctl that optionally drops looped timestamp with data. This only affects processes without CAP_NET_RAW. The policy is checked when timestamps are generated in the stack. It is possible for timestamps with data to be reported after the sysctl is set, if these were queued internally earlier. No vulnerability is immediately known that exploits knowledge gleaned from packet headers, but it may still be preferable to allow administrators to lock down this path at the cost of possible breakage of legacy applications. Signed-off-by: Willem de Bruijn <willemb@google.com> ---- Changes (v1 -> v2) - test socket CAP_NET_RAW instead of capable(CAP_NET_RAW) (rfc -> v1) - document the sysctl in Documentation/sysctl/net.txt - fix access control race: read .._OPT_TSONLY only once, use same value for permission check and skb generation. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net')
-rw-r--r--include/net/sock.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/net/sock.h b/include/net/sock.h
index 15341499786c..511ef7c8889b 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2239,6 +2239,7 @@ bool sk_net_capable(const struct sock *sk, int cap);
extern __u32 sysctl_wmem_max;
extern __u32 sysctl_rmem_max;
+extern int sysctl_tstamp_allow_data;
extern int sysctl_optmem_max;
extern __u32 sysctl_wmem_default;