mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-07-22 02:17:36 -04:00
Code Issues Packages Projects Releases Wiki Activity

bridge: cfm: reject invalid CCM interval at configuration time

Browse Source 
ccm_tx_work_expired() re-arms itself via queue_delayed_work() using
the configured exp_interval converted by interval_to_us(). When
exp_interval is BR_CFM_CCM_INTERVAL_NONE or out of range,
interval_to_us() returns 0, causing the worker to fire immediately in
a tight loop that allocates skbs until OOM.

Fix this by validating exp_interval at configuration time:

 - Constrain IFLA_BRIDGE_CFM_CC_CONFIG_EXP_INTERVAL to the valid range
   [BR_CFM_CCM_INTERVAL_3_3_MS, BR_CFM_CCM_INTERVAL_10_MIN] in the
   netlink policy so userspace cannot set an invalid value.

 - Reject starting CCM TX in br_cfm_cc_ccm_tx() when exp_interval has
   not yet been configured (defaults to 0 from kzalloc).

Fixes: 2be665c394 ("bridge: cfm: Netlink SET configuration Interface.")
Reported-by: Weiming Shi <bestswngs@gmail.com>
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260609065116.2818837-1-xmei5@asu.edu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Xiang Mei
2026-06-08 23:51:16 -07:00
committed by Jakub Kicinski
parent c33da0eeca
commit f3e02edd83
2 changed files with 9 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
net/bridge/br_cfm.c
View File

@@ -805,6 +805,12 @@ int br_cfm_cc_ccm_tx(struct net_bridge *br, const u32 instance,
goto save;
}
if (!interval_to_us(mep->cc_config.exp_interval)) {
NL_SET_ERR_MSG_MOD(extack,
"Invalid CCM interval");
return -EINVAL;
}
/* Start delayed work to transmit CCM frames. It is done with zero delay
* to send first frame immediately
*/

4
net/bridge/br_cfm_netlink.c
View File

@@ -34,7 +34,9 @@ br_cfm_cc_config_policy[IFLA_BRIDGE_CFM_CC_CONFIG_MAX + 1] = {
[IFLA_BRIDGE_CFM_CC_CONFIG_UNSPEC] = { .type = NLA_REJECT },
[IFLA_BRIDGE_CFM_CC_CONFIG_INSTANCE] = { .type = NLA_U32 },
[IFLA_BRIDGE_CFM_CC_CONFIG_ENABLE] = { .type = NLA_U32 },
[IFLA_BRIDGE_CFM_CC_CONFIG_EXP_INTERVAL] = { .type = NLA_U32 },
[IFLA_BRIDGE_CFM_CC_CONFIG_EXP_INTERVAL] =
NLA_POLICY_RANGE(NLA_U32, BR_CFM_CCM_INTERVAL_3_3_MS,
BR_CFM_CCM_INTERVAL_10_MIN),
[IFLA_BRIDGE_CFM_CC_CONFIG_EXP_MAID] = {
.type = NLA_BINARY, .len = CFM_MAID_LENGTH },
};