linux/net/xfrm
Eric Dumazet 92f1655aa2 net: fix __dst_negative_advice() race
__dst_negative_advice() does not enforce proper RCU rules when
sk->dst_cache must be cleared, leading to possible UAF.

RCU rules are that we must first clear sk->sk_dst_cache,
then call dst_release(old_dst).

Note that sk_dst_reset(sk) is implementing this protocol correctly,
while __dst_negative_advice() uses the wrong order.

Given that ip6_negative_advice() has special logic
against RTF_CACHE, this means each of the three ->negative_advice()
existing methods must perform the sk_dst_reset() themselves.

Note the check against NULL dst is centralized in
__dst_negative_advice(), there is no need to duplicate
it in various callbacks.

Many thanks to Clement Lecigne for tracking this issue.

This old bug became visible after the blamed commit, using UDP sockets.

Fixes: a87cb3e48e ("net: Facility to report route quality of connected sockets")
Reported-by: Clement Lecigne <clecigne@google.com>
Diagnosed-by: Clement Lecigne <clecigne@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <tom@herbertland.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240528114353.1794151-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-29 17:34:49 -07:00
..
espintcp.c net: move netdev_max_backlog to net_hotdata 2024-03-07 21:12:42 -08:00
Kconfig ipsec: Select CRYPTO_AEAD 2023-10-01 16:28:14 +08:00
Makefile bpf: xfrm: Add bpf_xdp_get_xfrm_state() kfunc 2023-12-14 17:12:49 -08:00
xfrm_algo.c net: fill in MODULE_DESCRIPTION()s for xfrm 2024-02-09 14:12:01 -08:00
xfrm_compat.c xfrm: Add Direction to the SA in or out 2024-05-01 10:05:11 +02:00
xfrm_device.c xfrm: Add Direction to the SA in or out 2024-05-01 10:05:11 +02:00
xfrm_hash.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
xfrm_hash.h xfrm: add state hashtable keyed by seq 2021-05-14 13:52:01 +02:00
xfrm_inout.h xfrm: move xfrm4_extract_header to common helper 2020-05-06 09:40:08 +02:00
xfrm_input.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-05-09 10:01:01 -07:00
xfrm_interface_bpf.c bpf: treewide: Annotate BPF kfuncs in BTF 2024-01-31 20:40:56 -08:00
xfrm_interface_core.c rtnetlink: allow rtnl_fill_link_netnsid() to run under RCU protection 2024-05-07 11:14:50 +02:00
xfrm_ipcomp.c net: introduce and use skb_frag_fill_page_desc() 2023-05-13 19:47:56 +01:00
xfrm_output.c xfrm: set skb control buffer based on packet offload as well 2024-03-05 10:49:44 +01:00
xfrm_policy.c net: fix __dst_negative_advice() race 2024-05-29 17:34:49 -07:00
xfrm_proc.c xfrm: Add dir validation to "in" data path lookup 2024-05-01 10:06:27 +02:00
xfrm_replay.c xfrm: Add Direction to the SA in or out 2024-05-01 10:05:11 +02:00
xfrm_state_bpf.c bpf: treewide: Annotate BPF kfuncs in BTF 2024-01-31 20:40:56 -08:00
xfrm_state.c xfrm: Add Direction to the SA in or out 2024-05-01 10:05:11 +02:00
xfrm_sysctl.c net: Remove ctl_table sentinel elements from several networking subsystems 2024-05-03 13:29:42 +01:00
xfrm_user.c xfrm: Restrict SA direction attribute to specific netlink message types 2024-05-01 10:06:59 +02:00