Jeremy Kerr 2405f64a95 mctp: perform route lookups under a RCU read-side lock ... commit 5093bbfc10 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2023-10-19 23:11:06 +02:00
..
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	2023-10-19 23:11:06 +02:00