On 07/31/2015 02:12 AM, Cong Wang wrote:
When we share an action within a filter, the bind refcnt
should increase, therefore we should not call tcf_hash_release().
Cc: Jamal Hadi Salim <j...@mojatatu.com>
Cc: Daniel Borkmann <dan...@iogearbox.net>
Signed-off-by: Cong Wang <xiyou.wangc...@gmail.com>
Signed-off-by: Cong Wang <cw...@twopensource.com>
Seems like this slipped in via commit 1a29321ed045. The ugly thing is that
this leads to a use-after-free.
# tc actions add action pedit munge offset 2 u16 at 0 0f0000000 22 set 11500
# tc actions show action pedit
action order 0: pedit action pass keys 1
index 1 ref 1 bind 0
key #0 at 0: val 00002cec mask ffff0000
# tc filter add dev foo parent 1: bpf bytecode "$FOO" flowid 1:1 action pedit
index 1
# tc filter show dev foo
filter parent 1: protocol all pref 49152 bpf
filter parent 1: protocol all pref 49152 bpf handle 0x1 flowid 1:1 bytecode
'1,6 0 0 4294967295'
action order 1: pedit action pass keys 1
index 1 ref 1 bind 0
key #0 at 0: val 00002cec mask ffff0000
# tc actions del action pedit index 1
.... and now you can wait for the next egress packet. ;)
Thanks for the fix Cong!
Fixes: 1a29321ed045 ("net_sched: act: Dont increment refcnt on replace")
Acked-by: Daniel Borkmann <dan...@iogearbox.net>
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
