linux/net/mctp
Jeremy Kerr 5093bbfc10 mctp: perform route lookups under a RCU read-side lock
Our current route lookups (mctp_route_lookup and mctp_route_lookup_null)
traverse the net's route list without the RCU read lock held. This means
the route lookup is subject to preemption, resulting in an potential
grace period expiry, and so an eventual kfree() while we still have the
route pointer.

Add the proper read-side critical section locks around the route
lookups, preventing premption and a possible parallel kfree.

The remaining net->mctp.routes accesses are already under a
rcu_read_lock, or protected by the RTNL for updates.

Based on an analysis from Sili Luo <rootlab@huawei.com>, where
introducing a delay in the route lookup could cause a UAF on
simultaneous sendmsg() and route deletion.

Reported-by: Sili Luo <rootlab@huawei.com>
Fixes: 889b7da23a ("mctp: Add initial routing framework")
Cc: stable@vger.kernel.org
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/29c4b0e67dc1bf3571df3982de87df90cae9b631.1696837310.git.jk@codeconstruct.com.au
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-10 19:43:22 -07:00
..
test Networking changes for 5.19. 2022-05-25 12:22:58 -07:00
af_mctp.c sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES) 2023-06-24 15:50:13 -07:00
device.c mctp: Remove device type check at unregister 2022-12-19 17:20:22 -08:00
Kconfig mctp: Add flow extension to skb 2021-10-29 13:23:51 +01:00
Makefile mctp: Add test utils 2021-10-03 14:35:41 +01:00
neigh.c mctp: replace mctp_address_ok with more fine-grained helpers 2022-02-18 21:24:28 -08:00
route.c mctp: perform route lookups under a RCU read-side lock 2023-10-10 19:43:22 -07:00