korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-15 08:14:15 +08:00
Code Issues Packages Projects Releases Wiki Activity
56440d7ec2
linux/include
History
Eric Dumazet 56440d7ec2 genetlink: hold RCU in genlmsg_mcast() 
While running net selftests with CONFIG_PROVE_RCU_LIST=y I saw
one lockdep splat [1].

genlmsg_mcast() uses for_each_net_rcu(), and must therefore hold RCU.

Instead of letting all callers guard genlmsg_multicast_allns()
with a rcu_read_lock()/rcu_read_unlock() pair, do it in genlmsg_mcast().

This also means the @flags parameter is useless, we need to always use
GFP_ATOMIC.

[1]
[10882.424136] =============================
[10882.424166] WARNING: suspicious RCU usage
[10882.424309] 6.12.0-rc2-virtme #1156 Not tainted
[10882.424400] -----------------------------
[10882.424423] net/netlink/genetlink.c:1940 RCU-list traversed in non-reader section!!
[10882.424469]
other info that might help us debug this:

[10882.424500]
rcu_scheduler_active = 2, debug_locks = 1
[10882.424744] 2 locks held by ip/15677:
[10882.424791] #0: ffffffffb6b491b0 (cb_lock){++++}-{3:3}, at: genl_rcv (net/netlink/genetlink.c:1219)
[10882.426334] #1: ffffffffb6b49248 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg (net/netlink/genetlink.c:61 net/netlink/genetlink.c:57 net/netlink/genetlink.c:1209)
[10882.426465]
stack backtrace:
[10882.426805] CPU: 14 UID: 0 PID: 15677 Comm: ip Not tainted 6.12.0-rc2-virtme #1156
[10882.426919] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[10882.427046] Call Trace:
[10882.427131]  <TASK>
[10882.427244] dump_stack_lvl (lib/dump_stack.c:123)
[10882.427335] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822)
[10882.427387] genlmsg_multicast_allns (net/netlink/genetlink.c:1940 (discriminator 7) net/netlink/genetlink.c:1977 (discriminator 7))
[10882.427436] l2tp_tunnel_notify.constprop.0 (net/l2tp/l2tp_netlink.c:119) l2tp_netlink
[10882.427683] l2tp_nl_cmd_tunnel_create (net/l2tp/l2tp_netlink.c:253) l2tp_netlink
[10882.427748] genl_family_rcv_msg_doit (net/netlink/genetlink.c:1115)
[10882.427834] genl_rcv_msg (net/netlink/genetlink.c:1195 net/netlink/genetlink.c:1210)
[10882.427877] ? __pfx_l2tp_nl_cmd_tunnel_create (net/l2tp/l2tp_netlink.c:186) l2tp_netlink
[10882.427927] ? __pfx_genl_rcv_msg (net/netlink/genetlink.c:1201)
[10882.427959] netlink_rcv_skb (net/netlink/af_netlink.c:2551)
[10882.428069] genl_rcv (net/netlink/genetlink.c:1220)
[10882.428095] netlink_unicast (net/netlink/af_netlink.c:1332 net/netlink/af_netlink.c:1357)
[10882.428140] netlink_sendmsg (net/netlink/af_netlink.c:1901)
[10882.428210] ____sys_sendmsg (net/socket.c:729 (discriminator 1) net/socket.c:744 (discriminator 1) net/socket.c:2607 (discriminator 1))

Fixes: 33f72e6f0c ("l2tp : multicast notification to the registered listeners")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Chapman <jchapman@katalix.com>
Cc: Tom Parkin <tparkin@katalix.com>
Cc: Johannes Berg <johannes.berg@intel.com>
Link: https://patch.msgid.link/20241011171217.3166614-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-15 17:52:58 -07:00
..
acpi Power management updates for 6.12-rc1 2024-09-16 07:47:50 +02:00
asm-generic move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
clocksource
crypto move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
cxl cxl: Move mailbox related bits to the same context 2024-09-12 08:38:01 -07:00
drm Short summary of fixes pull: 2024-10-01 08:15:55 +10:00
dt-bindings soc: convert ep93xx to devicetree 2024-09-26 12:00:25 -07:00
keys KEYS: Remove unused declarations 2024-09-20 18:28:26 +03:00
kunit The core clk framework is left largely untouched this time around except for 2024-09-23 15:01:48 -07:00
kvm
linux net: enetc: add missing static descriptor and inline keyword 2024-10-11 15:59:15 -07:00
math-emu
media media: cec: move cec_get/put_device to header 2024-09-05 20:12:15 +02:00
memory
misc
net genetlink: hold RCU in genlmsg_mcast() 2024-10-15 17:52:58 -07:00
pcmcia
ras
rdma move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
rv
scsi move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
soc soc: driver updates for 6.12 2024-09-17 10:48:09 +02:00
sound ALSA: hda: fix trigger_tstamp_latched 2024-10-02 12:50:24 +02:00
target move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
trace for-6.12-rc1-tag 2024-10-04 10:05:13 -07:00
uapi Including fixes from ieee802154, bluetooth and netfilter. 2024-10-03 09:44:00 -07:00
ufs Many singleton patches - please see the various changelogs for details. 2024-09-21 08:20:50 -07:00
vdso random: vDSO: add a __vdso_getrandom prototype for all architectures 2024-09-13 17:28:35 +02:00
video
xen xen: sync elfnote.h from xen tree 2024-09-25 14:15:04 +02:00