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Dexuan Cui 3b9f7b0a19 ACPI: scan: Harden acpi_device_add() against device ID overflows
commit a58015d638cd4e4555297b04bec9b49028369075 upstream.

Linux VM on Hyper-V crashes with the latest mainline:

[    4.069624] detected buffer overflow in strcpy
[    4.077733] kernel BUG at lib/string.c:1149!
..
[    4.085819] RIP: 0010:fortify_panic+0xf/0x11
...
[    4.085819] Call Trace:
[    4.085819]  acpi_device_add.cold.15+0xf2/0xfb
[    4.085819]  acpi_add_single_object+0x2a6/0x690
[    4.085819]  acpi_bus_check_add+0xc6/0x280
[    4.085819]  acpi_ns_walk_namespace+0xda/0x1aa
[    4.085819]  acpi_walk_namespace+0x9a/0xc2
[    4.085819]  acpi_bus_scan+0x78/0x90
[    4.085819]  acpi_scan_init+0xfa/0x248
[    4.085819]  acpi_init+0x2c1/0x321
[    4.085819]  do_one_initcall+0x44/0x1d0
[    4.085819]  kernel_init_freeable+0x1ab/0x1f4

This is because of the recent buffer overflow detection in the
commit 6a39e62abbaf ("lib: string.h: detect intra-object overflow in
fortified string functions")

Here acpi_device_bus_id->bus_id can only hold 14 characters, while the
the acpi_device_hid(device) returns a 22-char string
"HYPER_V_GEN_COUNTER_V1".

Per ACPI Spec v6.2, Section 6.1.5 _HID (Hardware ID), if the ID is a
string, it must be of the form AAA#### or NNNN####, i.e. 7 chars or 8
chars.

The field bus_id in struct acpi_device_bus_id was originally defined as
char bus_id[9], and later was enlarged to char bus_id[15] in 2007 in the
commit bb0958544f ("ACPI: use more understandable bus_id for ACPI
devices")

Fix the issue by changing the field bus_id to const char *, and use
kstrdup_const() to initialize it.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Tested-By: Jethro Beekman <jethro@fortanix.com>
[ rjw: Subject change, whitespace adjustment ]
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-19 18:27:21 +01:00
arch MIPS: relocatable: fix possible boot hangup with KASLR enabled 2021-01-19 18:27:20 +01:00
block block: fix use-after-free in disk_part_iter_next 2021-01-17 14:17:05 +01:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto crypto: asym_tpm: correct zero out potential secrets 2021-01-12 20:18:17 +01:00
Documentation dt-bindings: display: sii902x: Add supply bindings 2021-01-19 18:27:19 +01:00
drivers ACPI: scan: Harden acpi_device_add() against device ID overflows 2021-01-19 18:27:21 +01:00
fs cifs: fix interrupted close commands 2021-01-19 18:27:19 +01:00
include xsk: Fix race in SKB mode transmit with shared cq 2021-01-17 14:17:05 +01:00
init exec: Transform exec_update_mutex into a rw_semaphore 2021-01-09 13:46:24 +01:00
ipc ipc: adjust proc_ipc_sem_dointvec definition to match prototype 2020-09-05 12:14:29 -07:00
kernel tracing/kprobes: Do the notrace functions check without kprobes on ftrace 2021-01-19 18:27:19 +01:00
lib lib/genalloc: fix the overflow when size is too big 2021-01-12 20:18:16 +01:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm mm: make wait_on_page_writeback() wait for multiple pending writebacks 2021-01-12 20:18:22 +01:00
net net: drop bogus skb with CHECKSUM_PARTIAL and offset beyond end of trimmed packet 2021-01-17 14:17:06 +01:00
samples samples/bpf: Fix possible hang in xdpsock with multiple threads 2020-12-30 11:53:49 +01:00
scripts depmod: handle the case of /sbin/depmod without /sbin in PATH 2021-01-12 20:18:16 +01:00
security ima: Don't modify file descriptor mode on the fly 2020-12-30 11:54:17 +01:00
sound ASoC: dapm: remove widget from dirty list on free 2021-01-19 18:27:17 +01:00
tools tools/bootconfig: Add tracing_on support to helper scripts 2021-01-19 18:27:19 +01:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt kvm: check tlbs_dirty directly 2021-01-12 20:18:22 +01:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: docs: ignore sphinx_*/ directories 2020-09-10 10:44:31 -06:00
.mailmap mailmap: add two more addresses of Uwe Kleine-König 2020-12-06 10:19:07 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Jason Cooper to CREDITS 2020-11-30 10:20:34 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-12-10 15:30:13 -08:00
Makefile Linux 5.10.8 2021-01-17 14:17:06 +01:00
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.