In the Linux kernel, the following vulnerability has been resolved:
mptcp: pm: Fix uaf in __timer_delete_sync
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.
Vendor | Product | Version | CPE |
---|---|---|---|
linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
[
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"net/mptcp/pm_netlink.c"
],
"versions": [
{
"version": "00cfd77b9063",
"lessThan": "67409b358500",
"status": "affected",
"versionType": "git"
},
{
"version": "00cfd77b9063",
"lessThan": "6452b162549c",
"status": "affected",
"versionType": "git"
},
{
"version": "00cfd77b9063",
"lessThan": "12134a652b0a",
"status": "affected",
"versionType": "git"
},
{
"version": "00cfd77b9063",
"lessThan": "b4cd80b03389",
"status": "affected",
"versionType": "git"
}
]
},
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "affected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"net/mptcp/pm_netlink.c"
],
"versions": [
{
"version": "5.10",
"status": "affected"
},
{
"version": "0",
"lessThan": "5.10",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.1.111",
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.6.52",
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.10.11",
"lessThanOrEqual": "6.10.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.11",
"lessThanOrEqual": "*",
"status": "unaffected",
"versionType": "original_commit_for_fix"
}
]
}
]