In the Linux kernel, the following vulnerability has been resolved:
rtc: cmos: Fix event handler registration ordering issue
Because acpi_install_fixed_event_handler() enables the event
automatically on success, it is incorrect to call it before the
handler routine passed to it is ready to handle events.
Unfortunately, the rtc-cmos driver does exactly the incorrect thing
by calling cmos_wake_setup(), which passes rtc_handler() to
acpi_install_fixed_event_handler(), before cmos_do_probe(), because
rtc_handler() uses dev_get_drvdata() to get to the cmos object
pointer and the driver data pointer is only populated in
cmos_do_probe().
This leads to a NULL pointer dereference in rtc_handler() on boot
if the RTC fixed event happens to be active at the init time.
To address this issue, change the initialization ordering of the
driver so that cmos_wake_setup() is always called after a successful
cmos_do_probe() call.
While at it, change cmos_pnp_probe() to call cmos_do_probe() after
the initial if () statement used for computing the IRQ argument to
be passed to cmos_do_probe() which is cleaner than calling it in
each branch of that if () (local variable "irq" can be of type int,
because it is passed to that function as an argument of type int).
Note that commit 6492fed7d8c9 ("rtc: rtc-cmos: Do not check
ACPI_FADT_LOW_POWER_S0") caused this issue to affect a larger number
of systems, because previously it only affected systems with
ACPI_FADT_LOW_POWER_S0 set, but it is present regardless of that
commit.
In the Linux kernel, the following vulnerability has been resolved:
x86/mm/ident_map: Use gbpages only where full GB page should be mapped.
When ident_pud_init() uses only GB pages to create identity maps, large
ranges of addresses not actually requested can be included in the resulting
table; a 4K request will map a full GB. This can include a lot of extra
address space past that requested, including areas marked reserved by the
BIOS. That allows processor speculation into reserved regions, that on UV
systems can cause system halts.
Only use GB pages when map creation requests include the full GB page of
space. Fall back to using smaller 2M pages when only portions of a GB page
are included in the request.
No attempt is made to coalesce mapping requests. If a request requires a
map entry at the 2M (pmd) level, subsequent mapping requests within the
same 1G region will also be at the pmd level, even if adjacent or
overlapping such requests could have been combined to map a full GB page.
Existing usage starts with larger regions and then adds smaller regions, so
this should not have any great consequence.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix system hang while resume with TBT monitor
[Why]
Connected with a Thunderbolt monitor and do the suspend and the system
may hang while resume.
The TBT monitor HPD will be triggered during the resume procedure
and call the drm_client_modeset_probe() while
struct drm_connector connector->dev->master is NULL.
It will mess up the pipe topology after resume.
[How]
Skip the TBT monitor HPD during the resume procedure because we
currently will probe the connectors after resume by default.
(cherry picked from commit 453f86a26945207a16b8f66aaed5962dc2b95b85)
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: update DML2 policy EnhancedPrefetchScheduleAccelerationFinal DCN35
[WHY & HOW]
Mismatch in DCN35 DML2 cause bw validation failed to acquire unexpected DPP pipe to cause
grey screen and system hang. Remove EnhancedPrefetchScheduleAccelerationFinal value override
to match HW spec.
(cherry picked from commit 9dad21f910fcea2bdcff4af46159101d7f9cd8ba)
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix i_data_sem unlock order in ext4_ind_migrate()
Fuzzing reports a possible deadlock in jbd2_log_wait_commit.
This issue is triggered when an EXT4_IOC_MIGRATE ioctl is set to require
synchronous updates because the file descriptor is opened with O_SYNC.
This can lead to the jbd2_journal_stop() function calling
jbd2_might_wait_for_commit(), potentially causing a deadlock if the
EXT4_IOC_MIGRATE call races with a write(2) system call.
This problem only arises when CONFIG_PROVE_LOCKING is enabled. In this
case, the jbd2_might_wait_for_commit macro locks jbd2_handle in the
jbd2_journal_stop function while i_data_sem is locked. This triggers
lockdep because the jbd2_journal_start function might also lock the same
jbd2_handle simultaneously.
Found by Linux Verification Center (linuxtesting.org) with syzkaller.
Rule: add
In the Linux kernel, the following vulnerability has been resolved:
ALSA: asihpi: Fix potential OOB array access
ASIHPI driver stores some values in the static array upon a response
from the driver, and its index depends on the firmware. We shouldn't
trust it blindly.
This patch adds a sanity check of the array index to fit in the array
size.
In the Linux kernel, the following vulnerability has been resolved:
wifi: mwifiex: Fix memcpy() field-spanning write warning in mwifiex_cmd_802_11_scan_ext()
Replace one-element array with a flexible-array member in
`struct host_cmd_ds_802_11_scan_ext`.
With this, fix the following warning:
elo 16 17:51:58 surfacebook kernel: ------------[ cut here ]------------
elo 16 17:51:58 surfacebook kernel: memcpy: detected field-spanning write (size 243) of single field "ext_scan->tlv_buffer" at drivers/net/wireless/marvell/mwifiex/scan.c:2239 (size 1)
elo 16 17:51:58 surfacebook kernel: WARNING: CPU: 0 PID: 498 at drivers/net/wireless/marvell/mwifiex/scan.c:2239 mwifiex_cmd_802_11_scan_ext+0x83/0x90 [mwifiex]
In the Linux kernel, the following vulnerability has been resolved:
cpufreq: amd-pstate: add check for cpufreq_cpu_get's return value
cpufreq_cpu_get may return NULL. To avoid NULL-dereference check it
and return in case of error.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
In the Linux kernel, the following vulnerability has been resolved:
exec: don't WARN for racy path_noexec check
Both i_mode and noexec checks wrapped in WARN_ON stem from an artifact
of the previous implementation. They used to legitimately check for the
condition, but that got moved up in two commits:
633fb6ac3980 ("exec: move S_ISREG() check earlier")
0fd338b2d2cd ("exec: move path_noexec() check earlier")
Instead of being removed said checks are WARN_ON'ed instead, which
has some debug value.
However, the spurious path_noexec check is racy, resulting in
unwarranted warnings should someone race with setting the noexec flag.
One can note there is more to perm-checking whether execve is allowed
and none of the conditions are guaranteed to still hold after they were
tested for.
Additionally this does not validate whether the code path did any perm
checking to begin with -- it will pass if the inode happens to be
regular.
Keep the redundant path_noexec() check even though it's mindless
nonsense checking for guarantee that isn't given so drop the WARN.
Reword the commentary and do small tidy ups while here.
[brauner: keep redundant path_noexec() check]
In the Linux kernel, the following vulnerability has been resolved:
cpufreq: Avoid a bad reference count on CPU node
In the parse_perf_domain function, if the call to
of_parse_phandle_with_args returns an error, then the reference to the
CPU device node that was acquired at the start of the function would not
be properly decremented.
Address this by declaring the variable with the __free(device_node)
cleanup attribute.