Description
In the Linux kernel, the following vulnerability has been resolved: tipc: hold a reference to nodes found by link name tipc_node_find_by_name() returns a node after dropping its RCU read lock without taking a reference. The LINK_SET, LINK_GET and LINK_RESET_STATS handlers then lock and access the node, racing with timer-driven cleanup of a down peer. Generic netlink serialization does not exclude the node timer. The following interleaving can leave a handler using a freed node: CPU 0: find the node under RCU and release the node read lock CPU 1: tipc_node_timeout() clears the links and unlinks the down node CPU 1: drop the list and timer references, queuing tipc_node_free() CPU 0: leave the RCU read-side critical section CPU 1: complete the grace period and free the node CPU 0: acquire the node lock through the stale pointer LINK_SET also uses the node's media address after releasing the node lock, when passing queued packets to tipc_bearer_xmit(). KASAN on v7.3-rc5 reported: BUG: KASAN: slab-use-after-free in _raw_read_lock_bh Write of size 4 at addr ffff88807e06f008 by task poc/92 Call Trace: _raw_read_lock_bh kernel/locking/spinlock.c:287 tipc_nl_node_set_link net/tipc/node.c:2475 genl_family_rcv_msg_doit net/netlink/genetlink.c:1114 genl_rcv_msg net/netlink/genetlink.c:1209 netlink_rcv_skb net/netlink/af_netlink.c:2575 Allocated by task 0: tipc_node_create net/tipc/node.c:539 tipc_node_check_dest net/tipc/node.c:1196 tipc_disc_rcv net/tipc/discover.c:252 Freed by task 92: kfree mm/slub.c:6801 rcu_core kernel/rcu/tree.c:2919 Last potentially related work creation: __call_rcu_common.constprop.0 kernel/rcu/tree.c:3181 tipc_node_timeout net/tipc/node.c:814 Acquire a reference to the selected node with kref_get_unless_zero() before leaving RCU, returning NULL if the node has already been released. Release that reference on every caller exit after the last node access, including transmission in LINK_SET. Keep the existing link lookup order and locking so concurrent link removal still takes the existing error paths.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
6a939f365bdb03a74b4617bdb4402fc08da088b9 to < 384edc67201f8561b7de952647b923f0524b1f36affected6a939f365bdb03a74b4617bdb4402fc08da088b9 to < 5b7e58e8be90f4e8530e7a60372d003dfa7fd666affected6a939f365bdb03a74b4617bdb4402fc08da088b9 to < 92f3b3368722631e933a4db0cf8bd578ed08cd9caffected6a939f365bdb03a74b4617bdb4402fc08da088b9 to < b60259d4047fbb735476c729dcf9306a038b6110affected6a939f365bdb03a74b4617bdb4402fc08da088b9 to < f17e70206a1e763fcca2578a8db3c4eed0f843a9affected6a939f365bdb03a74b4617bdb4402fc08da088b9 to < 1428c5f1d346a2e1ac9156713975a72246957009affected6a939f365bdb03a74b4617bdb4402fc08da088b9 to < 3c3b308ee6e25729a6cf09b69cdd0e093220d40baffected6a939f365bdb03a74b4617bdb4402fc08da088b9 to < 17e73bae400f6a434dc006e3bee92c94cf781954affected
Linux Linux
Default version status: affected
4.19affected0 to < 4.19unaffected5.10.273 to ≤ 5.10.*unaffected5.15.224 to ≤ 5.15.*unaffected6.1.191 to ≤ 6.1.*unaffected6.6.160 to ≤ 6.6.*unaffected6.12.113 to ≤ 6.12.*unaffected6.18.57 to ≤ 6.18.*unaffected7.2.11 to ≤ 7.2.*unaffected7.3 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/384edc67201f8561b7de952647b923f0524b1f36 ↗
- https://git.kernel.org/stable/c/5b7e58e8be90f4e8530e7a60372d003dfa7fd666 ↗
- https://git.kernel.org/stable/c/92f3b3368722631e933a4db0cf8bd578ed08cd9c ↗
- https://git.kernel.org/stable/c/b60259d4047fbb735476c729dcf9306a038b6110 ↗
- https://git.kernel.org/stable/c/f17e70206a1e763fcca2578a8db3c4eed0f843a9 ↗
- https://git.kernel.org/stable/c/1428c5f1d346a2e1ac9156713975a72246957009 ↗
- https://git.kernel.org/stable/c/3c3b308ee6e25729a6cf09b69cdd0e093220d40b ↗
- https://git.kernel.org/stable/c/17e73bae400f6a434dc006e3bee92c94cf781954 ↗