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Rob Herring 9885440b16 PCI: Fix pci_host_bridge struct device release/free handling
The PCI code has several paths where the struct pci_host_bridge is freed
directly. This is wrong because it contains a struct device which is
refcounted and should be freed using put_device(). This can result in
use-after-free errors. I think this problem has existed since 2012 with
commit 7b54366358 ("PCI: add generic device into pci_host_bridge
struct"). It generally hasn't mattered as most host bridge drivers are
still built-in and can't unbind.

The problem is a struct device should never be freed directly once
device_initialize() is called and a ref is held, but that doesn't happen
until pci_register_host_bridge(). There's then a window between allocating
the host bridge and pci_register_host_bridge() where kfree should be used.
This is fragile and requires callers to do the right thing. To fix this, we
need to split device_register() into device_initialize() and device_add()
calls, so that the host bridge struct is always freed by using a
put_device().

devm_pci_alloc_host_bridge() is using devm_kzalloc() to allocate struct
pci_host_bridge which will be freed directly. Instead, we can use a custom
devres action to call put_device().

Link: https://lore.kernel.org/r/20200513223859.11295-2-robh@kernel.org
Reported-by: Anders Roxell <anders.roxell@linaro.org>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2020-05-14 16:36:35 -05:00
arch A set of three patches to fix the fallout of the newly added split lock 2020-04-12 10:17:16 -07:00
block block-5.7-2020-04-10 2020-04-10 10:06:54 -07:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto x86: update AS_* macros to binutils >=2.23, supporting ADX and AVX2 2020-04-09 00:12:48 +09:00
Documentation Time(keeping) updates: 2020-04-12 10:13:14 -07:00
drivers PCI: Fix pci_host_bridge struct device release/free handling 2020-05-14 16:36:35 -05:00
fs 10 smb fixes most RDMA (smbdirect) related, also add experimental support for swap over SMB3 mounts, and also adds fix which improves performance of signed connections 2020-04-12 09:41:01 -07:00
include Three small fixes/updates for the locking core code: 2020-04-12 09:47:10 -07:00
init Kbuild updates for v5.7 (2nd) 2020-04-11 09:46:12 -07:00
ipc ipc/util.c: sysvipc_find_ipc() should increase position index 2020-04-10 15:36:22 -07:00
kernel Time(keeping) updates: 2020-04-12 10:13:14 -07:00
lib Kbuild updates for v5.7 (2nd) 2020-04-11 09:46:12 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm Merge branch 'akpm' (patches from Andrew) 2020-04-10 17:57:48 -07:00
net Kbuild updates for v5.7 (2nd) 2020-04-11 09:46:12 -07:00
samples samples/hw_breakpoint: drop use of kallsyms_lookup_name() 2020-04-07 10:43:44 -07:00
scripts kbuild: add dummy toolchains to enable all cc-option etc. in Kconfig 2020-04-09 00:13:45 +09:00
security Keyrings fixes 2020-04-04 12:24:47 -07:00
sound sound fixes for 5.7-rc1 2020-04-10 12:27:06 -07:00
tools Kbuild updates for v5.7 (2nd) 2020-04-11 09:46:12 -07:00
usr kbuild: fix comment about missing include guard detection 2020-04-11 12:09:48 +09:00
virt KVM: Pass kvm_init()'s opaque param to additional arch funcs 2020-03-31 10:48:03 -04:00
.clang-format clang-format: Update with the latest for_each macro list 2020-03-06 21:50:05 +01:00
.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: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
.mailmap mailmap: Add Sedat Dilek (replacement for expired email address) 2020-04-11 09:28:34 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Hand MIPS over to Thomas 2020-02-24 22:43:18 -08:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS MAINTAINERS: sort field names for all entries 2020-04-12 11:04:58 -07:00
Makefile Linux 5.7-rc1 2020-04-12 12:35:55 -07:00
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.