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Eric Dumazet 7e2556e400 bonding: avoid lockdep confusion in bond_get_stats()
syzbot found that the following sequence produces a LOCKDEP splat [1]

ip link add bond10 type bond
ip link add bond11 type bond
ip link set bond11 master bond10

To fix this, we can use the already provided nest_level.

This patch also provides correct nesting for dev->addr_list_lock

[1]
WARNING: possible recursive locking detected
4.18.0-rc6+ #167 Not tainted
--------------------------------------------
syz-executor751/4439 is trying to acquire lock:
(____ptrval____) (&(&bond->stats_lock)->rlock){+.+.}, at: spin_lock include/linux/spinlock.h:310 [inline]
(____ptrval____) (&(&bond->stats_lock)->rlock){+.+.}, at: bond_get_stats+0xb4/0x560 drivers/net/bonding/bond_main.c:3426

but task is already holding lock:
(____ptrval____) (&(&bond->stats_lock)->rlock){+.+.}, at: spin_lock include/linux/spinlock.h:310 [inline]
(____ptrval____) (&(&bond->stats_lock)->rlock){+.+.}, at: bond_get_stats+0xb4/0x560 drivers/net/bonding/bond_main.c:3426

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&(&bond->stats_lock)->rlock);
  lock(&(&bond->stats_lock)->rlock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

3 locks held by syz-executor751/4439:
 #0: (____ptrval____) (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77
 #1: (____ptrval____) (&(&bond->stats_lock)->rlock){+.+.}, at: spin_lock include/linux/spinlock.h:310 [inline]
 #1: (____ptrval____) (&(&bond->stats_lock)->rlock){+.+.}, at: bond_get_stats+0xb4/0x560 drivers/net/bonding/bond_main.c:3426
 #2: (____ptrval____) (rcu_read_lock){....}, at: bond_get_stats+0x0/0x560 include/linux/compiler.h:215

stack backtrace:
CPU: 0 PID: 4439 Comm: syz-executor751 Not tainted 4.18.0-rc6+ #167
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
 print_deadlock_bug kernel/locking/lockdep.c:1765 [inline]
 check_deadlock kernel/locking/lockdep.c:1809 [inline]
 validate_chain kernel/locking/lockdep.c:2405 [inline]
 __lock_acquire.cold.64+0x1fb/0x486 kernel/locking/lockdep.c:3435
 lock_acquire+0x1e4/0x540 kernel/locking/lockdep.c:3924
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144
 spin_lock include/linux/spinlock.h:310 [inline]
 bond_get_stats+0xb4/0x560 drivers/net/bonding/bond_main.c:3426
 dev_get_stats+0x10f/0x470 net/core/dev.c:8316
 bond_get_stats+0x232/0x560 drivers/net/bonding/bond_main.c:3432
 dev_get_stats+0x10f/0x470 net/core/dev.c:8316
 rtnl_fill_stats+0x4d/0xac0 net/core/rtnetlink.c:1169
 rtnl_fill_ifinfo+0x1aa6/0x3fb0 net/core/rtnetlink.c:1611
 rtmsg_ifinfo_build_skb+0xc8/0x190 net/core/rtnetlink.c:3268
 rtmsg_ifinfo_event.part.30+0x45/0xe0 net/core/rtnetlink.c:3300
 rtmsg_ifinfo_event net/core/rtnetlink.c:3297 [inline]
 rtnetlink_event+0x144/0x170 net/core/rtnetlink.c:4716
 notifier_call_chain+0x180/0x390 kernel/notifier.c:93
 __raw_notifier_call_chain kernel/notifier.c:394 [inline]
 raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
 call_netdevice_notifiers_info+0x3f/0x90 net/core/dev.c:1735
 call_netdevice_notifiers net/core/dev.c:1753 [inline]
 netdev_features_change net/core/dev.c:1321 [inline]
 netdev_change_features+0xb3/0x110 net/core/dev.c:7759
 bond_compute_features.isra.47+0x585/0xa50 drivers/net/bonding/bond_main.c:1120
 bond_enslave+0x1b25/0x5da0 drivers/net/bonding/bond_main.c:1755
 bond_do_ioctl+0x7cb/0xae0 drivers/net/bonding/bond_main.c:3528
 dev_ifsioc+0x43c/0xb30 net/core/dev_ioctl.c:327
 dev_ioctl+0x1b5/0xcc0 net/core/dev_ioctl.c:493
 sock_do_ioctl+0x1d3/0x3e0 net/socket.c:992
 sock_ioctl+0x30d/0x680 net/socket.c:1093
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:684
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701
 __do_sys_ioctl fs/ioctl.c:708 [inline]
 __se_sys_ioctl fs/ioctl.c:706 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x440859
Code: e8 2c af 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b 10 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffc51a92878 EFLAGS: 00000213 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000440859
RDX: 0000000020000040 RSI: 0000000000008990 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000022d5880 R11: 0000000000000213 R12: 0000000000007390
R13: 0000000000401db0 R14: 0000000000000000 R15: 0000000000000000

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jay Vosburgh <j.vosburgh@gmail.com>
Cc: Veaceslav Falico <vfalico@gmail.com>
Cc: Andy Gospodarek <andy@greyhouse.net>

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-01 09:34:07 -07:00
arch Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-07-30 21:40:37 -07:00
block for-linus-20180727 2018-07-27 12:51:00 -07:00
certs certs/blacklist: fix const confusion 2018-06-26 09:43:03 -07:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2018-07-19 07:32:44 -07:00
Documentation USB fixes for 4.18-rc7 2018-07-26 09:29:29 -07:00
drivers bonding: avoid lockdep confusion in bond_get_stats() 2018-08-01 09:34:07 -07:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs squashfs: more metadata hardening 2018-07-30 17:29:17 -07:00
include Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-07-30 11:45:30 -07:00
init Kbuild fixes for v4.18 2018-06-30 13:05:30 -07:00
ipc ipc/sem.c: prevent queue.status tearing in semop 2018-07-26 19:38:03 -07:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-07-30 21:40:37 -07:00
lib kasan: only select SLUB_DEBUG with SYSFS=y 2018-07-26 19:38:03 -07:00
LICENSES LICENSES: Add Linux-OpenIB license text 2018-04-27 16:41:53 -06:00
mm zswap: re-check zswap_is_full() after do zswap_shrink() 2018-07-26 19:38:03 -07:00
net ipv4: frags: handle possible skb truesize change 2018-07-31 14:41:29 -07:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-07-18 19:32:54 -07:00
scripts Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-07-18 19:32:54 -07:00
security selinux/stable-4.18 PR 20180629 2018-06-30 11:15:12 -07:00
sound ALSA: hda/realtek - Yet another Clevo P950 quirk entry 2018-07-18 12:17:46 +02:00
tools virtio: last-minute fixes 2018-07-31 09:35:32 -07:00
usr kbuild: rename built-in.o to built-in.a 2018-03-26 02:01:19 +09:00
virt Miscellaneous bugfixes, plus a small patchlet related to Spectre v2. 2018-07-18 11:08:44 -07:00
.clang-format clang-format: add configuration file 2018-04-11 10:28:35 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Add hch to .get_maintainer.ignore 2015-08-21 14:30:10 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap Merge branch 'asoc-4.17' into asoc-4.18 for compress dependencies 2018-04-26 12:24:28 +01:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS/CREDITS: Drop METAG ARCHITECTURE 2018-03-05 16:34:24 +00:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: add basic helper macros to scripts/Kconfig.include 2018-05-29 03:31:19 +09:00
MAINTAINERS Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-07-30 11:45:30 -07:00
Makefile Linux 4.18-rc7 2018-07-29 14:44:52 -07:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -06:00

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.
See Documentation/00-INDEX for a list of what is contained in each file.

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.