diff options
| author | Davide Caratti <dcaratti@redhat.com> | 2019-03-20 17:00:15 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-03-21 23:26:42 +0300 |
| commit | fe384e2fa36ca084a456fd30558cccc75b4b3fbd (patch) | |
| tree | e90582ded10560c8daf4e857a06966f212027c76 /include/net | |
| parent | 7e0c8892df7d0316ec853adbf84db536cd53258c (diff) | |
| download | linux-fe384e2fa36ca084a456fd30558cccc75b4b3fbd.tar.xz | |
net/sched: don't dereference a->goto_chain to read the chain index
callers of tcf_gact_goto_chain_index() can potentially read an old value
of the chain index, or even dereference a NULL 'goto_chain' pointer,
because 'goto_chain' and 'tcfa_action' are read in the traffic path
without caring of concurrent write in the control path. The most recent
value of chain index can be read also from a->tcfa_action (it's encoded
there together with TC_ACT_GOTO_CHAIN bits), so we don't really need to
dereference 'goto_chain': just read the chain id from the control action.
Fixes: e457d86ada27 ("net: sched: add couple of goto_chain helpers")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net')
| -rw-r--r-- | include/net/tc_act/tc_gact.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/net/tc_act/tc_gact.h b/include/net/tc_act/tc_gact.h index ee8d005f56fc..eb8f01c819e6 100644 --- a/include/net/tc_act/tc_gact.h +++ b/include/net/tc_act/tc_gact.h @@ -56,7 +56,7 @@ static inline bool is_tcf_gact_goto_chain(const struct tc_action *a) static inline u32 tcf_gact_goto_chain_index(const struct tc_action *a) { - return a->goto_chain->index; + return READ_ONCE(a->tcfa_action) & TC_ACT_EXT_VAL_MASK; } #endif /* __NET_TC_GACT_H */ |