diff options
| author | Paolo Abeni <pabeni@redhat.com> | 2018-07-30 15:30:42 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-07-30 19:31:13 +0300 |
| commit | 802bfb19152c0fb4137c6ba72bcf042ee023e743 (patch) | |
| tree | 0330695824cf2ca9a5f5d270e4a161f7df857abf | |
| parent | c87fffc57adf7b772b3778a9521c3f2ff744ae82 (diff) | |
| download | linux-802bfb19152c0fb4137c6ba72bcf042ee023e743.tar.xz | |
net/sched: user-space can't set unknown tcfa_action values
Currently, when initializing an action, the user-space can specify
and use arbitrary values for the tcfa_action field. If the value
is unknown by the kernel, is implicitly threaded as TC_ACT_UNSPEC.
This change explicitly checks for unknown values at action creation
time, and explicitly convert them to TC_ACT_UNSPEC. No functional
changes are introduced, but this will allow introducing tcfa_action
values not exposed to user-space in a later patch.
Note: we can't use the above to hide TC_ACT_REDIRECT from user-space,
as the latter is already part of uAPI.
v3 -> v4:
- use an helper to check for action validity (JiriP)
- emit an extack for invalid actions (JiriP)
v4 -> v5:
- keep messages on a single line, drop net_warn (Marcelo)
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/uapi/linux/pkt_cls.h | 6 | ||||
| -rw-r--r-- | net/sched/act_api.c | 14 |
2 files changed, 18 insertions, 2 deletions
diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h index b4512254036b..48e5b5d49a34 100644 --- a/include/uapi/linux/pkt_cls.h +++ b/include/uapi/linux/pkt_cls.h @@ -45,6 +45,7 @@ enum { * the skb and act like everything * is alright. */ +#define TC_ACT_VALUE_MAX TC_ACT_TRAP /* There is a special kind of actions called "extended actions", * which need a value parameter. These have a local opcode located in @@ -55,11 +56,12 @@ enum { #define __TC_ACT_EXT_SHIFT 28 #define __TC_ACT_EXT(local) ((local) << __TC_ACT_EXT_SHIFT) #define TC_ACT_EXT_VAL_MASK ((1 << __TC_ACT_EXT_SHIFT) - 1) -#define TC_ACT_EXT_CMP(combined, opcode) \ - (((combined) & (~TC_ACT_EXT_VAL_MASK)) == opcode) +#define TC_ACT_EXT_OPCODE(combined) ((combined) & (~TC_ACT_EXT_VAL_MASK)) +#define TC_ACT_EXT_CMP(combined, opcode) (TC_ACT_EXT_OPCODE(combined) == opcode) #define TC_ACT_JUMP __TC_ACT_EXT(1) #define TC_ACT_GOTO_CHAIN __TC_ACT_EXT(2) +#define TC_ACT_EXT_OPCODE_MAX TC_ACT_GOTO_CHAIN /* Action type identifiers*/ enum { diff --git a/net/sched/act_api.c b/net/sched/act_api.c index b43df1e25c6d..229d63c99be2 100644 --- a/net/sched/act_api.c +++ b/net/sched/act_api.c @@ -786,6 +786,15 @@ static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb) return c; } +static bool tcf_action_valid(int action) +{ + int opcode = TC_ACT_EXT_OPCODE(action); + + if (!opcode) + return action <= TC_ACT_VALUE_MAX; + return opcode <= TC_ACT_EXT_OPCODE_MAX || action == TC_ACT_UNSPEC; +} + struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp, struct nlattr *nla, struct nlattr *est, char *name, int ovr, int bind, @@ -895,6 +904,11 @@ struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp, } } + if (!tcf_action_valid(a->tcfa_action)) { + NL_SET_ERR_MSG(extack, "invalid action value, using TC_ACT_UNSPEC instead"); + a->tcfa_action = TC_ACT_UNSPEC; + } + return a; err_mod: |