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Vladimir Oltean cd356010ce net: phy: mscc: fix deadlock in phy_ethtool_{get,set}_wol()
Since the blamed commit, phy_ethtool_get_wol() and phy_ethtool_set_wol()
acquire phydev->lock, but the mscc phy driver implementations,
vsc85xx_wol_get() and vsc85xx_wol_set(), acquire the same lock as well,
resulting in a deadlock.

$ ip link set swp3 down
============================================
WARNING: possible recursive locking detected
mscc_felix 0000:00:00.5 swp3: Link is Down
--------------------------------------------
ip/375 is trying to acquire lock:
ffff3d7e82e987a8 (&dev->lock){+.+.}-{4:4}, at: vsc85xx_wol_get+0x2c/0xf4

but task is already holding lock:
ffff3d7e82e987a8 (&dev->lock){+.+.}-{4:4}, at: phy_ethtool_get_wol+0x3c/0x6c

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

       CPU0
       ----
  lock(&dev->lock);
  lock(&dev->lock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

2 locks held by ip/375:
 #0: ffffd43b2a955788 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x144/0x58c
 #1: ffff3d7e82e987a8 (&dev->lock){+.+.}-{4:4}, at: phy_ethtool_get_wol+0x3c/0x6c

Call trace:
 __mutex_lock+0x98/0x454
 mutex_lock_nested+0x2c/0x38
 vsc85xx_wol_get+0x2c/0xf4
 phy_ethtool_get_wol+0x50/0x6c
 phy_suspend+0x84/0xcc
 phy_state_machine+0x1b8/0x27c
 phy_stop+0x70/0x154
 phylink_stop+0x34/0xc0
 dsa_port_disable_rt+0x2c/0xa4
 dsa_slave_close+0x38/0xec
 __dev_close_many+0xc8/0x16c
 __dev_change_flags+0xdc/0x218
 dev_change_flags+0x24/0x6c
 do_setlink+0x234/0xea4
 __rtnl_newlink+0x46c/0x878
 rtnl_newlink+0x50/0x7c
 rtnetlink_rcv_msg+0x16c/0x58c

Removing the mutex_lock(&phydev->lock) calls from the driver restores
the functionality.

Fixes: 2f987d4866 ("net: phy: Add locks to ethtool functions")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20230314153025.2372970-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-15 21:33:22 -07:00
arch Networking fixes for 6.3-rc2, including fixes from netfilter, bpf 2023-03-09 10:56:58 -08:00
block block-6.3-2023-03-03 2023-03-03 10:21:39 -08:00
certs Kbuild updates for v6.3 2023-02-26 11:53:25 -08:00
crypto Networking changes for 6.3. 2023-02-21 18:24:12 -08:00
Documentation xdp: add xdp_set_features_flag utility routine 2023-03-10 21:33:47 -08:00
drivers net: phy: mscc: fix deadlock in phy_ethtool_{get,set}_wol() 2023-03-15 21:33:22 -07:00
fs udf: Warn if block mapping is done for in-ICB files 2023-03-06 16:38:25 +01:00
include net: tunnels: annotate lockless accesses to dev->needed_headroom 2023-03-15 00:04:04 -07:00
init Kbuild updates for v6.3 2023-02-26 11:53:25 -08:00
io_uring io_uring-6.3-2023-03-03 2023-03-03 10:25:29 -08:00
ipc Merge branch 'work.namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2023-02-24 19:20:07 -08:00
kernel Networking fixes for 6.3-rc2, including fixes from netfilter, bpf 2023-03-09 10:56:58 -08:00
lib cpumask: re-introduce constant-sized cpumask optimizations 2023-03-05 14:30:34 -08:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm mm: avoid gcc complaint about pointer casting 2023-03-04 14:03:27 -08:00
net net/smc: Fix device de-init sequence 2023-03-15 08:15:19 +00:00
rust Rust fixes for 6.3-rc1 2023-03-03 14:51:15 -08:00
samples LoongArch changes for v6.3 2023-03-01 09:27:00 -08:00
scripts Remove Intel compiler support 2023-03-05 10:49:37 -08:00
security capability: just use a 'u64' instead of a 'u32[2]' array 2023-03-01 10:01:22 -08:00
sound sound fixes for 6.3-rc1 2023-03-04 10:53:59 -08:00
tools selftest: Add test for bind() conflicts. 2023-03-15 00:24:10 -07:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt KVM/riscv changes for 6.3 2023-02-15 12:33:28 -05:00
.clang-format cpumask: re-introduce constant-sized cpumask optimizations 2023-03-05 14:30:34 -08:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for *.dtso files 2023-02-26 15:28:23 +09:00
.gitignore .gitignore: ignore *.cover and *.mbx 2023-02-05 18:51:22 +09:00
.mailmap MAINTAINERS: make my email address consistent 2023-03-10 18:11:48 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS There is no particular theme here - mainly quick hits all over the tree. 2023-02-23 17:55:40 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: make my email address consistent 2023-03-10 18:11:48 -08:00
Makefile Linux 6.3-rc1 2023-03-05 14:52:03 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -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.

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.