Taehee Yoo 43511a6a16 bonding: fix suspicious RCU usage in bond_ipsec_del_sa()
[ Upstream commit a22c39b831a081da9b2c488bd970a4412d926f30 ]

To dereference bond->curr_active_slave, it uses rcu_dereference().
But it and the caller doesn't acquire RCU so a warning occurs.
So add rcu_read_lock().

Test commands:
    ip netns add A
    ip netns exec A bash
    modprobe netdevsim
    echo "1 1" > /sys/bus/netdevsim/new_device
    ip link add bond0 type bond
    ip link set eth0 master bond0
    ip link set eth0 up
    ip link set bond0 up
    ip x s add proto esp dst 14.1.1.1 src 15.1.1.1 spi 0x07 mode \
transport reqid 0x07 replay-window 32 aead 'rfc4106(gcm(aes))' \
0x44434241343332312423222114131211f4f3f2f1 128 sel src 14.0.0.52/24 \
dst 14.0.0.70/24 proto tcp offload dev bond0 dir in
    ip x s f

Splat looks like:
=============================
WARNING: suspicious RCU usage
5.13.0-rc3+ #1168 Not tainted
-----------------------------
drivers/net/bonding/bond_main.c:448 suspicious rcu_dereference_check()
usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
2 locks held by ip/705:
 #0: ffff888106701780 (&net->xfrm.xfrm_cfg_mutex){+.+.}-{3:3},
at: xfrm_netlink_rcv+0x59/0x80 [xfrm_user]
 #1: ffff8880075b0098 (&x->lock){+.-.}-{2:2},
at: xfrm_state_delete+0x16/0x30

stack backtrace:
CPU: 6 PID: 705 Comm: ip Not tainted 5.13.0-rc3+ #1168
Call Trace:
 dump_stack+0xa4/0xe5
 bond_ipsec_del_sa+0x16a/0x1c0 [bonding]
 __xfrm_state_delete+0x51f/0x730
 xfrm_state_delete+0x1e/0x30
 xfrm_state_flush+0x22f/0x390
 xfrm_flush_sa+0xd8/0x260 [xfrm_user]
 ? xfrm_flush_policy+0x290/0x290 [xfrm_user]
 xfrm_user_rcv_msg+0x331/0x660 [xfrm_user]
 ? rcu_read_lock_sched_held+0x91/0xc0
 ? xfrm_user_state_lookup.constprop.39+0x320/0x320 [xfrm_user]
 ? find_held_lock+0x3a/0x1c0
 ? mutex_lock_io_nested+0x1210/0x1210
 ? sched_clock_cpu+0x18/0x170
 netlink_rcv_skb+0x121/0x350
[ ... ]

Fixes: 18cb261afd7b ("bonding: support hardware encryption offload to slaves")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-28 14:35:33 +02:00
2021-07-25 14:36:21 +02:00
2020-10-17 11:18:18 -07:00
2021-07-25 14:36:22 +02:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Description
No description provided
Readme 5.7 GiB
Languages
C 97.6%
Assembly 1%
Shell 0.5%
Python 0.3%
Makefile 0.3%