In the Linux kernel, the following vulnerability has been resolved:
um: time-travel: fix time corruption
In 'basic' time-travel mode (without =inf-cpu or =ext), we
still get timer interrupts. These can happen at arbitrary
points in time, i.e. while in timer_read(), which pushes
time forward just a little bit. Then, if we happen to get
the interrupt after calculating the new time to push to,
but before actually finishing that, the interrupt will set
the time to a value that's incompatible with the forward,
and we'll crash because time goes backwards when we do the
forwarding.
Fix this by reading the time_travel_time, calculating the
adjustment, and doing the adjustment all with interrupts
disabled.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix disable_otg_wa logic
[Why]
When switching to another HDMI mode, we are unnecesarilly
disabling/enabling FIFO causing both HPO and DIG registers to be set at
the same time when only HPO is supposed to be set.
This can lead to a system hang the next time we change refresh rates as
there are cases when we don't disable OTG/FIFO but FIFO is enabled when
it isn't supposed to be.
[How]
Removing the enable/disable FIFO entirely.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix late derefrence 'dsc' check in 'link_set_dsc_pps_packet()'
In link_set_dsc_pps_packet(), 'struct display_stream_compressor *dsc'
was dereferenced in a DC_LOGGER_INIT(dsc->ctx->logger); before the 'dsc'
NULL pointer check.
Fixes the below:
drivers/gpu/drm/amd/amdgpu/../display/dc/link/link_dpms.c:905 link_set_dsc_pps_packet() warn: variable dereferenced before check 'dsc' (see line 903)
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix variable deferencing before NULL check in edp_setup_replay()
In edp_setup_replay(), 'struct dc *dc' & 'struct dmub_replay *replay'
was dereferenced before the pointer 'link' & 'replay' NULL check.
Fixes the below:
drivers/gpu/drm/amd/amdgpu/../display/dc/link/protocols/link_edp_panel_control.c:947 edp_setup_replay() warn: variable dereferenced before check 'link' (see line 933)
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Refactor DMCUB enter/exit idle interface
[Why]
We can hang in place trying to send commands when the DMCUB isn't
powered on.
[How]
We need to exit out of the idle state prior to sending a command,
but the process that performs the exit also invokes a command itself.
Fixing this issue involves the following:
1. Using a software state to track whether or not we need to start
the process to exit idle or notify idle.
It's possible for the hardware to have exited an idle state without
driver knowledge, but entering one is always restricted to a driver
allow - which makes the SW state vs HW state mismatch issue purely one
of optimization, which should seldomly be hit, if at all.
2. Refactor any instances of exit/notify idle to use a single wrapper
that maintains this SW state.
This works simialr to dc_allow_idle_optimizations, but works at the
DMCUB level and makes sure the state is marked prior to any notify/exit
idle so we don't enter an infinite loop.
3. Make sure we exit out of idle prior to sending any commands or
waiting for DMCUB idle.
This patch takes care of 1/2. A future patch will take care of wrapping
DMCUB command submission with calls to this new interface.
In the Linux kernel, the following vulnerability has been resolved:
thermal: intel: hfi: Add syscore callbacks for system-wide PM
The kernel allocates a memory buffer and provides its location to the
hardware, which uses it to update the HFI table. This allocation occurs
during boot and remains constant throughout runtime.
When resuming from hibernation, the restore kernel allocates a second
memory buffer and reprograms the HFI hardware with the new location as
part of a normal boot. The location of the second memory buffer may
differ from the one allocated by the image kernel.
When the restore kernel transfers control to the image kernel, its HFI
buffer becomes invalid, potentially leading to memory corruption if the
hardware writes to it (the hardware continues to use the buffer from the
restore kernel).
It is also possible that the hardware "forgets" the address of the memory
buffer when resuming from "deep" suspend. Memory corruption may also occur
in such a scenario.
To prevent the described memory corruption, disable HFI when preparing to
suspend or hibernate. Enable it when resuming.
Add syscore callbacks to handle the package of the boot CPU (packages of
non-boot CPUs are handled via CPU offline). Syscore ops always run on the
boot CPU. Additionally, HFI only needs to be disabled during "deep" suspend
and hibernation. Syscore ops only run in these cases.
[ rjw: Comment adjustment, subject and changelog edits ]
In the Linux kernel, the following vulnerability has been resolved:
bpf: Check rcu_read_lock_trace_held() before calling bpf map helpers
These three bpf_map_{lookup,update,delete}_elem() helpers are also
available for sleepable bpf program, so add the corresponding lock
assertion for sleepable bpf program, otherwise the following warning
will be reported when a sleepable bpf program manipulates bpf map under
interpreter mode (aka bpf_jit_enable=0):
WARNING: CPU: 3 PID: 4985 at kernel/bpf/helpers.c:40 ......
CPU: 3 PID: 4985 Comm: test_progs Not tainted 6.6.0+ #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ......
RIP: 0010:bpf_map_lookup_elem+0x54/0x60
......
Call Trace:
<TASK>
? __warn+0xa5/0x240
? bpf_map_lookup_elem+0x54/0x60
? report_bug+0x1ba/0x1f0
? handle_bug+0x40/0x80
? exc_invalid_op+0x18/0x50
? asm_exc_invalid_op+0x1b/0x20
? __pfx_bpf_map_lookup_elem+0x10/0x10
? rcu_lockdep_current_cpu_online+0x65/0xb0
? rcu_is_watching+0x23/0x50
? bpf_map_lookup_elem+0x54/0x60
? __pfx_bpf_map_lookup_elem+0x10/0x10
___bpf_prog_run+0x513/0x3b70
__bpf_prog_run32+0x9d/0xd0
? __bpf_prog_enter_sleepable_recur+0xad/0x120
? __bpf_prog_enter_sleepable_recur+0x3e/0x120
bpf_trampoline_6442580665+0x4d/0x1000
__x64_sys_getpgid+0x5/0x30
? do_syscall_64+0x36/0xb0
entry_SYSCALL_64_after_hwframe+0x6e/0x76
</TASK>
In the Linux kernel, the following vulnerability has been resolved:
ext4: avoid online resizing failures due to oversized flex bg
When we online resize an ext4 filesystem with a oversized flexbg_size,
mkfs.ext4 -F -G 67108864 $dev -b 4096 100M
mount $dev $dir
resize2fs $dev 16G
the following WARN_ON is triggered:
==================================================================
WARNING: CPU: 0 PID: 427 at mm/page_alloc.c:4402 __alloc_pages+0x411/0x550
Modules linked in: sg(E)
CPU: 0 PID: 427 Comm: resize2fs Tainted: G E 6.6.0-rc5+ #314
RIP: 0010:__alloc_pages+0x411/0x550
Call Trace:
<TASK>
__kmalloc_large_node+0xa2/0x200
__kmalloc+0x16e/0x290
ext4_resize_fs+0x481/0xd80
__ext4_ioctl+0x1616/0x1d90
ext4_ioctl+0x12/0x20
__x64_sys_ioctl+0xf0/0x150
do_syscall_64+0x3b/0x90
==================================================================
This is because flexbg_size is too large and the size of the new_group_data
array to be allocated exceeds MAX_ORDER. Currently, the minimum value of
MAX_ORDER is 8, the minimum value of PAGE_SIZE is 4096, the corresponding
maximum number of groups that can be allocated is:
(PAGE_SIZE << MAX_ORDER) / sizeof(struct ext4_new_group_data) ≈ 21845
And the value that is down-aligned to the power of 2 is 16384. Therefore,
this value is defined as MAX_RESIZE_BG, and the number of groups added
each time does not exceed this value during resizing, and is added multiple
times to complete the online resizing. The difference is that the metadata
in a flex_bg may be more dispersed.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Wake DMCUB before executing GPINT commands
[Why]
DMCUB can be in idle when we attempt to interface with the HW through
the GPINT mailbox resulting in a system hang.
[How]
Add dc_wake_and_execute_gpint() to wrap the wake, execute, sleep
sequence.
If the GPINT executes successfully then DMCUB will be put back into
sleep after the optional response is returned.
It functions similar to the inbox command interface.