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Borislav Petkov b11f2d6b80 EDAC/ghes: Check whether the driver is on the safe list correctly
[ Upstream commit 251c54ea26fa6029b01a76161a37a12fde5124e4 ]

With CONFIG_DEBUG_TEST_DRIVER_REMOVE=y, a system would try to probe,
unregister and probe again a driver.

When ghes_edac is attempted to be loaded on a system which is not on
the safe platforms list, ghes_edac_register() would return early. The
unregister counterpart ghes_edac_unregister() would still attempt to
unregister and exit early at the refcount test, leading to the refcount
underflow below.

In order to not do *anything* on the unregister path too, reuse the
force_load parameter and check it on that path too, before fumbling with
the refcount.

  ghes_edac: ghes_edac_register: entry
  ghes_edac: ghes_edac_register: return -ENODEV
  ------------[ cut here ]------------
  refcount_t: underflow; use-after-free.
  WARNING: CPU: 10 PID: 1 at lib/refcount.c:28 refcount_warn_saturate+0xb9/0x100
  Modules linked in:
  CPU: 10 PID: 1 Comm: swapper/0 Not tainted 5.9.0-rc4+ #12
  Hardware name: GIGABYTE MZ01-CE1-00/MZ01-CE1-00, BIOS F02 08/29/2018
  RIP: 0010:refcount_warn_saturate+0xb9/0x100
  Code: 82 e8 fb 8f 4d 00 90 0f 0b 90 90 c3 80 3d 55 4c f5 00 00 75 88 c6 05 4c 4c f5 00 01 90 48 c7 c7 d0 8a 10 82 e8 d8 8f 4d 00 90 <0f> 0b 90 90 c3 80 3d 30 4c f5 00 00 0f 85 61 ff ff ff c6 05 23 4c
  RSP: 0018:ffffc90000037d58 EFLAGS: 00010292
  RAX: 0000000000000026 RBX: ffff88840b8da000 RCX: 0000000000000000
  RDX: 0000000000000001 RSI: ffffffff8216b24f RDI: 00000000ffffffff
  RBP: ffff88840c662e00 R08: 0000000000000001 R09: 0000000000000001
  R10: 0000000000000001 R11: 0000000000000046 R12: 0000000000000000
  R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000
  FS:  0000000000000000(0000) GS:ffff88840ee80000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000000 CR3: 0000800002211000 CR4: 00000000003506e0
  Call Trace:
   ghes_edac_unregister
   ghes_remove
   platform_drv_remove
   really_probe
   driver_probe_device
   device_driver_attach
   __driver_attach
   ? device_driver_attach
   ? device_driver_attach
   bus_for_each_dev
   bus_add_driver
   driver_register
   ? bert_init
   ghes_init
   do_one_initcall
   ? rcu_read_lock_sched_held
   kernel_init_freeable
   ? rest_init
   kernel_init
   ret_from_fork
   ...
  ghes_edac: ghes_edac_unregister: FALSE, refcount: -1073741824

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200911164950.GB19320@zn.tnic
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:18:14 +02:00
Documentation dt-bindings: sound: wm8994: Correct required supplies based on actual implementaion 2020-10-01 13:17:58 +02:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
arch s390/init: add missing __init annotations 2020-10-01 13:18:14 +02:00
block block: only call sched requeue_request() for scheduled requests 2020-09-23 12:40:37 +02:00
certs PKCS#7: Refactor verify_pkcs7_signature() 2019-08-05 18:40:18 -04:00
crypto crypto: af_alg - Work around empty control messages without MSG_MORE 2020-09-03 11:27:05 +02:00
drivers EDAC/ghes: Check whether the driver is on the safe list correctly 2020-10-01 13:18:14 +02:00
fs btrfs: qgroup: fix data leak caused by race between writeback and truncate 2020-10-01 13:18:10 +02:00
include svcrdma: Fix backchannel return code 2020-10-01 13:18:01 +02:00
init exec: Add exec_update_mutex to replace cred_guard_mutex 2020-10-01 13:17:47 +02:00
ipc ipc/util.c: sysvipc_find_ipc() incorrectly updates position index 2020-05-20 08:20:16 +02:00
kernel lockdep: fix order in trace_hardirqs_off_caller() 2020-10-01 13:18:14 +02:00
lib kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec() 2020-10-01 13:17:10 +02:00
mm mm: memcontrol: fix stat-corrupting race in charge moving 2020-10-01 13:18:08 +02:00
net net: openvswitch: use div_u64() for 64-by-32 divisions 2020-10-01 13:18:12 +02:00
samples bpf: Fix fds_example SIGSEGV error 2020-08-19 08:16:03 +02:00
scripts checkpatch: fix the usage of capture group ( ... ) 2020-09-09 19:12:37 +02:00
security device_cgroup: Fix RCU list debugging warning 2020-10-01 13:18:13 +02:00
sound ASoC: Intel: bytcr_rt5640: Add quirk for MPMAN Converter9 2-in-1 2020-10-01 13:18:13 +02:00
tools perf parse-events: Use strcmp() to compare the PMU name 2020-10-01 13:18:12 +02:00
usr initramfs: restore default compression behavior 2020-04-08 09:08:38 +02:00
virt KVM: arm64: vgic-its: Fix memory leak on the error path of vgic_add_lpi() 2020-10-01 13:17:56 +02:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Modules updates for v5.4 2019-09-22 10:34:46 -07:00
.mailmap ARM: SoC fixes 2019-11-10 13:41:59 -08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer 2019-10-10 08:12:51 -07:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS Documentation/llvm: add documentation on building w/ Clang/LLVM 2020-08-26 10:40:46 +02:00
Makefile Linux 5.4.68 2020-09-26 18:03:16 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

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.