67409b3585
commit b4cd80b0338945a94972ac3ed54f8338d2da2076 upstream.
There are two paths to access mptcp_pm_del_add_timer, result in a race
condition:
CPU1 CPU2
==== ====
net_rx_action
napi_poll netlink_sendmsg
__napi_poll netlink_unicast
process_backlog netlink_unicast_kernel
__netif_receive_skb genl_rcv
__netif_receive_skb_one_core netlink_rcv_skb
NF_HOOK genl_rcv_msg
ip_local_deliver_finish genl_family_rcv_msg
ip_protocol_deliver_rcu genl_family_rcv_msg_doit
tcp_v4_rcv mptcp_pm_nl_flush_addrs_doit
tcp_v4_do_rcv mptcp_nl_remove_addrs_list
tcp_rcv_established mptcp_pm_remove_addrs_and_subflows
tcp_data_queue remove_anno_list_by_saddr
mptcp_incoming_options mptcp_pm_del_add_timer
mptcp_pm_del_add_timer kfree(entry)
In remove_anno_list_by_saddr(running on CPU2), after leaving the critical
zone protected by "pm.lock", the entry will be released, which leads to the
occurrence of uaf in the mptcp_pm_del_add_timer(running on CPU1).
Keeping a reference to add_timer inside the lock, and calling
sk_stop_timer_sync() with this reference, instead of "entry->add_timer".
Move list_del(&entry->list) to mptcp_pm_del_add_timer and inside the pm lock,
do not directly access any members of the entry outside the pm lock, which
can avoid similar "entry->x" uaf.
Fixes:
|
||
|---|---|---|
| .. | ||
| bpf.c | ||
| crypto_test.c | ||
| crypto.c | ||
| ctrl.c | ||
| diag.c | ||
| Kconfig | ||
| Makefile | ||
| mib.c | ||
| mib.h | ||
| mptcp_diag.c | ||
| options.c | ||
| pm_netlink.c | ||
| pm_userspace.c | ||
| pm.c | ||
| protocol.c | ||
| protocol.h | ||
| sockopt.c | ||
| subflow.c | ||
| syncookies.c | ||
| token_test.c | ||
| token.c | ||