kernel/linux.git/drivers/acpi/custom_method.c, branch v6.6.132

ACPI: custom_method: fix a possible memory leak

2021-04-28T17:17:54+00:00

In cm_write(), if the 'buf' is allocated memory but not fully consumed, it is possible to reallocate the buffer without freeing it by passing '*ppos' as 0 on a subsequent call. Add an explicit kfree() before kzalloc() to prevent the possible memory leak. Fixes: 526b4af47f44 ("ACPI: Split out custom_method functionality into an own driver") Signed-off-by: Mark Langsdorf Cc: 5.4+ # 5.4+ Signed-off-by: Rafael J. Wysocki

ACPI: custom_method: fix potential use-after-free issue

2021-04-28T17:15:30+00:00

In cm_write(), buf is always freed when reaching the end of the function. If the requested count is less than table.length, the allocated buffer will be freed but subsequent calls to cm_write() will still try to access it. Remove the unconditional kfree(buf) at the end of the function and set the buf to NULL in the -EINVAL error path to match the rest of function. Fixes: 03d1571d9513 ("ACPI: custom_method: fix memory leaks") Signed-off-by: Mark Langsdorf Cc: 5.4+ # 5.4+ Signed-off-by: Rafael J. Wysocki

ACPI: custom_method: fix a coding style issue

2021-04-08T14:27:02+00:00

Fix the following coding style issue reported by checkpatch.pl ERROR: "foo * bar" should be "foo *bar" FILE: drivers/acpi/custom_method.c:22: +static ssize_t cm_write(struct file *file, const char __user * user_buf, Signed-off-by: Xiaofei Tan Signed-off-by: Rafael J. Wysocki

ACPI: custom_method: Remove dead ACPICA debug code

2020-09-25T16:25:51+00:00

ACPICA debug code _COMPONENT and ACPI_MODULE_NAME() is not used in custom_method.c, remove it. Signed-off-by: Hanjun Guo [ rjw: Subject edit ] Signed-off-by: Rafael J. Wysocki

Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

2019-09-28T15:14:15+00:00

Pull kernel lockdown mode from James Morris: "This is the latest iteration of the kernel lockdown patchset, from Matthew Garrett, David Howells and others. From the original description: This patchset introduces an optional kernel lockdown feature, intended to strengthen the boundary between UID 0 and the kernel. When enabled, various pieces of kernel functionality are restricted. Applications that rely on low-level access to either hardware or the kernel may cease working as a result - therefore this should not be enabled without appropriate evaluation beforehand. The majority of mainstream distributions have been carrying variants of this patchset for many years now, so there's value in providing a doesn't meet every distribution requirement, but gets us much closer to not requiring external patches. There are two major changes since this was last proposed for mainline: - Separating lockdown from EFI secure boot. Background discussion is covered here: https://lwn.net/Articles/751061/ - Implementation as an LSM, with a default stackable lockdown LSM module. This allows the lockdown feature to be policy-driven, rather than encoding an implicit policy within the mechanism. The new locked_down LSM hook is provided to allow LSMs to make a policy decision around whether kernel functionality that would allow tampering with or examining the runtime state of the kernel should be permitted. The included lockdown LSM provides an implementation with a simple policy intended for general purpose use. This policy provides a coarse level of granularity, controllable via the kernel command line: lockdown={integrity|confidentiality} Enable the kernel lockdown feature. If set to integrity, kernel features that allow userland to modify the running kernel are disabled. If set to confidentiality, kernel features that allow userland to extract confidential information from the kernel are also disabled. This may also be controlled via /sys/kernel/security/lockdown and overriden by kernel configuration. New or existing LSMs may implement finer-grained controls of the lockdown features. Refer to the lockdown_reason documentation in include/linux/security.h for details. The lockdown feature has had signficant design feedback and review across many subsystems. This code has been in linux-next for some weeks, with a few fixes applied along the way. Stephen Rothwell noted that commit 9d1f8be5cf42 ("bpf: Restrict bpf when kernel lockdown is in confidentiality mode") is missing a Signed-off-by from its author. Matthew responded that he is providing this under category (c) of the DCO" * 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits) kexec: Fix file verification on S390 security: constify some arrays in lockdown LSM lockdown: Print current->comm in restriction messages efi: Restrict efivar_ssdt_load when the kernel is locked down tracefs: Restrict tracefs when the kernel is locked down debugfs: Restrict debugfs when the kernel is locked down kexec: Allow kexec_file() with appropriate IMA policy when locked down lockdown: Lock down perf when in confidentiality mode bpf: Restrict bpf when kernel lockdown is in confidentiality mode lockdown: Lock down tracing and perf kprobes when in confidentiality mode lockdown: Lock down /proc/kcore x86/mmiotrace: Lock down the testmmiotrace module lockdown: Lock down module params that specify hardware parameters (eg. ioport) lockdown: Lock down TIOCSSERIAL lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down acpi: Disable ACPI table override if the kernel is locked down acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down ACPI: Limit access to custom_method when the kernel is locked down x86/msr: Restrict MSR access when the kernel is locked down x86: Lock down IO port access when the kernel is locked down ...

ACPI: custom_method: fix memory leaks

2019-09-02T21:17:22+00:00

In cm_write(), 'buf' is allocated through kzalloc(). In the following execution, if an error occurs, 'buf' is not deallocated, leading to memory leaks. To fix this issue, free 'buf' before returning the error. Fixes: 526b4af47f44 ("ACPI: Split out custom_method functionality into an own driver") Signed-off-by: Wenwen Wang Signed-off-by: Rafael J. Wysocki

ACPI: Limit access to custom_method when the kernel is locked down

2019-08-20T04:54:16+00:00

custom_method effectively allows arbitrary access to system memory, making it possible for an attacker to circumvent restrictions on module loading. Disable it if the kernel is locked down. Signed-off-by: Matthew Garrett Signed-off-by: David Howells Reviewed-by: Kees Cook cc: linux-acpi@vger.kernel.org Signed-off-by: James Morris

treewide: Add SPDX license identifier for more missed files

2019-05-21T08:50:45+00:00

Add SPDX license identifiers to all files which: - Have no license information of any form - Have MODULE_LICENCE("GPL*") inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

ACPI: no need to check return value of debugfs_create functions

2019-01-22T18:45:52+00:00

When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Signed-off-by: Greg Kroah-Hartman Signed-off-by: Rafael J. Wysocki

ACPI: custom_method: remove meaningless null check before debugfs_remove()

2018-09-10T10:46:51+00:00

debugfs_remove() has taken null pointer into account. So it is safe to remove the check before debugfs_remove(). Signed-off-by: zhong jiang Signed-off-by: Rafael J. Wysocki