| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to avoid NULL pointer dereference in f2fs_check_quota_consistency()
syzbot reported a f2fs bug as below:
Oops: gen[ 107.736417][ T5848] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 UID: 0 PID: 5848 Comm: syz-executor263 Tainted: G W 6.17.0-rc1-syzkaller-00014-g0e39a731820a #0 PREEMPT_{RT,(full)}
RIP: 0010:strcmp+0x3c/0xc0 lib/string.c:284
Call Trace:
<TASK>
f2fs_check_quota_consistency fs/f2fs/super.c:1188 [inline]
f2fs_check_opt_consistency+0x1378/0x2c10 fs/f2fs/super.c:1436
__f2fs_remount fs/f2fs/super.c:2653 [inline]
f2fs_reconfigure+0x482/0x1770 fs/f2fs/super.c:5297
reconfigure_super+0x224/0x890 fs/super.c:1077
do_remount fs/namespace.c:3314 [inline]
path_mount+0xd18/0xfe0 fs/namespace.c:4112
do_mount fs/namespace.c:4133 [inline]
__do_sys_mount fs/namespace.c:4344 [inline]
__se_sys_mount+0x317/0x410 fs/namespace.c:4321
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The direct reason is f2fs_check_quota_consistency() may suffer null-ptr-deref
issue in strcmp().
The bug can be reproduced w/ below scripts:
mkfs.f2fs -f /dev/vdb
mount -t f2fs -o usrquota /dev/vdb /mnt/f2fs
quotacheck -uc /mnt/f2fs/
umount /mnt/f2fs
mount -t f2fs -o usrjquota=aquota.user,jqfmt=vfsold /dev/vdb /mnt/f2fs
mount -t f2fs -o remount,usrjquota=,jqfmt=vfsold /dev/vdb /mnt/f2fs
umount /mnt/f2fs
So, before old_qname and new_qname comparison, we need to check whether
they are all valid pointers, fix it. |
| In the Linux kernel, the following vulnerability has been resolved:
PCI/pwrctrl: Fix double cleanup on devm_add_action_or_reset() failure
When devm_add_action_or_reset() fails, it calls the passed cleanup
function. Hence the caller must not repeat that cleanup.
Replace the "goto err_regulator_free" by the actual freeing, as there
will never be a need again for a second user of this label. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: pcm: Disable bottom softirqs as part of spin_lock_irq() on PREEMPT_RT
snd_pcm_group_lock_irq() acquires a spinlock_t and disables interrupts
via spin_lock_irq(). This also implicitly disables the handling of
softirqs such as TIMER_SOFTIRQ.
On PREEMPT_RT softirqs are preemptible and spin_lock_irq() does not
disable them. That means a timer can be invoked during spin_lock_irq()
on the same CPU. Due to synchronisations reasons local_bh_disable() has
a per-CPU lock named softirq_ctrl.lock which synchronizes individual
softirq against each other.
syz-bot managed to trigger a lockdep report where softirq_ctrl.lock is
acquired in hrtimer_cancel() in addition to hrtimer_run_softirq(). This
is a possible deadlock.
The softirq_ctrl.lock can not be made part of spin_lock_irq() as this
would lead to too much synchronisation against individual threads on the
system. To avoid the possible deadlock, softirqs must be manually
disabled before the lock is acquired.
Disable softirqs before the lock is acquired on PREEMPT_RT. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: dont report verifier bug for missing bpf_scc_visit on speculative path
Syzbot generated a program that triggers a verifier_bug() call in
maybe_exit_scc(). maybe_exit_scc() assumes that, when called for a
state with insn_idx in some SCC, there should be an instance of struct
bpf_scc_visit allocated for that SCC. Turns out the assumption does
not hold for speculative execution paths. See example in the next
patch.
maybe_scc_exit() is called from update_branch_counts() for states that
reach branch count of zero, meaning that path exploration for a
particular path is finished. Path exploration can finish in one of
three ways:
a. Verification error is found. In this case, update_branch_counts()
is called only for non-speculative paths.
b. Top level BPF_EXIT is reached. Such instructions are never a part of
an SCC, so compute_scc_callchain() in maybe_scc_exit() will return
false, and maybe_scc_exit() will return early.
c. A checkpoint is reached and matched. Checkpoints are created by
is_state_visited(), which calls maybe_enter_scc(), which allocates
bpf_scc_visit instances for checkpoints within SCCs.
Hence, for non-speculative symbolic execution paths, the assumption
still holds: if maybe_scc_exit() is called for a state within an SCC,
bpf_scc_visit instance must exist.
This patch removes the verifier_bug() call for speculative paths. |
| In the Linux kernel, the following vulnerability has been resolved:
blk-mq: fix potential deadlock while nr_requests grown
Allocate and free sched_tags while queue is freezed can deadlock[1],
this is a long term problem, hence allocate memory before freezing
queue and free memory after queue is unfreezed.
[1] https://lore.kernel.org/all/0659ea8d-a463-47c8-9180-43c719e106eb@linux.ibm.com/ |
| In the Linux kernel, the following vulnerability has been resolved:
blk-throttle: fix access race during throttle policy activation
On repeated cold boots we occasionally hit a NULL pointer crash in
blk_should_throtl() when throttling is consulted before the throttle
policy is fully enabled for the queue. Checking only q->td != NULL is
insufficient during early initialization, so blkg_to_pd() for the
throttle policy can still return NULL and blkg_to_tg() becomes NULL,
which later gets dereferenced.
Unable to handle kernel NULL pointer dereference
at virtual address 0000000000000156
...
pc : submit_bio_noacct+0x14c/0x4c8
lr : submit_bio_noacct+0x48/0x4c8
sp : ffff800087f0b690
x29: ffff800087f0b690 x28: 0000000000005f90 x27: ffff00068af393c0
x26: 0000000000080000 x25: 000000000002fbc0 x24: ffff000684ddcc70
x23: 0000000000000000 x22: 0000000000000000 x21: 0000000000000000
x20: 0000000000080000 x19: ffff000684ddcd08 x18: ffffffffffffffff
x17: 0000000000000000 x16: ffff80008132a550 x15: 0000ffff98020fff
x14: 0000000000000000 x13: 1fffe000d11d7021 x12: ffff000688eb810c
x11: ffff00077ec4bb80 x10: ffff000688dcb720 x9 : ffff80008068ef60
x8 : 00000a6fb8a86e85 x7 : 000000000000111e x6 : 0000000000000002
x5 : 0000000000000246 x4 : 0000000000015cff x3 : 0000000000394500
x2 : ffff000682e35e40 x1 : 0000000000364940 x0 : 000000000000001a
Call trace:
submit_bio_noacct+0x14c/0x4c8
verity_map+0x178/0x2c8
__map_bio+0x228/0x250
dm_submit_bio+0x1c4/0x678
__submit_bio+0x170/0x230
submit_bio_noacct_nocheck+0x16c/0x388
submit_bio_noacct+0x16c/0x4c8
submit_bio+0xb4/0x210
f2fs_submit_read_bio+0x4c/0xf0
f2fs_mpage_readpages+0x3b0/0x5f0
f2fs_readahead+0x90/0xe8
Tighten blk_throtl_activated() to also require that the throttle policy
bit is set on the queue:
return q->td != NULL &&
test_bit(blkcg_policy_throtl.plid, q->blkcg_pols);
This prevents blk_should_throtl() from accessing throttle group state
until policy data has been attached to blkgs. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Add NULL pointer checks in dc_stream cursor attribute functions
The function dc_stream_set_cursor_attributes() currently dereferences
the `stream` pointer and nested members `stream->ctx->dc->current_state`
without checking for NULL.
All callers of these functions, such as in
`dcn30_apply_idle_power_optimizations()` and
`amdgpu_dm_plane_handle_cursor_update()`, already perform NULL checks
before calling these functions.
Fixes below:
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c:336 dc_stream_program_cursor_attributes()
error: we previously assumed 'stream' could be null (see line 334)
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c
327 bool dc_stream_program_cursor_attributes(
328 struct dc_stream_state *stream,
329 const struct dc_cursor_attributes *attributes)
330 {
331 struct dc *dc;
332 bool reset_idle_optimizations = false;
333
334 dc = stream ? stream->ctx->dc : NULL;
^^^^^^
The old code assumed stream could be NULL.
335
--> 336 if (dc_stream_set_cursor_attributes(stream, attributes)) {
^^^^^^
The refactor added an unchecked dereference.
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c
313 bool dc_stream_set_cursor_attributes(
314 struct dc_stream_state *stream,
315 const struct dc_cursor_attributes *attributes)
316 {
317 bool result = false;
318
319 if (dc_stream_check_cursor_attributes(stream, stream->ctx->dc->current_state, attributes)) {
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Here.
This function used to check for if stream as NULL and return false at
the start. Probably we should add that back. |
| In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to avoid migrating empty section
It reports a bug from device w/ zufs:
F2FS-fs (dm-64): Inconsistent segment (173822) type [1, 0] in SSA and SIT
F2FS-fs (dm-64): Stopped filesystem due to reason: 4
Thread A Thread B
- f2fs_expand_inode_data
- f2fs_allocate_pinning_section
- f2fs_gc_range
- do_garbage_collect w/ segno #x
- writepage
- f2fs_allocate_data_block
- new_curseg
- allocate segno #x
The root cause is: fallocate on pinning file may race w/ block allocation
as above, result in do_garbage_collect() from fallocate() may migrate
segment which is just allocated by a log, the log will update segment type
in its in-memory structure, however GC will get segment type from on-disk
SSA block, once segment type changes by log, we can detect such
inconsistency, then shutdown filesystem.
In this case, on-disk SSA shows type of segno #173822 is 1 (SUM_TYPE_NODE),
however segno #173822 was just allocated as data type segment, so in-memory
SIT shows type of segno #173822 is 0 (SUM_TYPE_DATA).
Change as below to fix this issue:
- check whether current section is empty before gc
- add sanity checks on do_garbage_collect() to avoid any race case, result
in migrating segment used by log.
- btw, it fixes misc issue in printed logs: "SSA and SIT" -> "SIT and SSA". |
| In the Linux kernel, the following vulnerability has been resolved:
drm/msm: Fix bootup splat with separate_gpu_drm modparam
The drm_gem_for_each_gpuvm_bo() call from lookup_vma() accesses
drm_gem_obj.gpuva.list, which is not initialized when the drm driver
does not support DRIVER_GEM_GPUVA feature. Enable it for msm_kms
drm driver to fix the splat seen when msm.separate_gpu_drm=1 modparam
is set:
[ 9.506020] Unable to handle kernel paging request at virtual address fffffffffffffff0
[ 9.523160] Mem abort info:
[ 9.523161] ESR = 0x0000000096000006
[ 9.523163] EC = 0x25: DABT (current EL), IL = 32 bits
[ 9.523165] SET = 0, FnV = 0
[ 9.523166] EA = 0, S1PTW = 0
[ 9.523167] FSC = 0x06: level 2 translation fault
[ 9.523169] Data abort info:
[ 9.523170] ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000
[ 9.523171] CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[ 9.523172] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[ 9.523174] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000ad370f000
[ 9.523176] [fffffffffffffff0] pgd=0000000000000000, p4d=0000000ad4787403, pud=0000000ad4788403, pmd=0000000000000000
[ 9.523184] Internal error: Oops: 0000000096000006 [#1] SMP
[ 9.592968] CPU: 9 UID: 0 PID: 448 Comm: (udev-worker) Not tainted 6.17.0-rc4-assorted-fix-00005-g0e9bb53a2282-dirty #3 PREEMPT
[ 9.592970] Hardware name: Qualcomm CRD, BIOS 6.0.240718.BOOT.MXF.2.4-00515-HAMOA-1 07/18/2024
[ 9.592971] pstate: a1400005 (NzCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
[ 9.592973] pc : lookup_vma+0x28/0xe0 [msm]
[ 9.592996] lr : get_vma_locked+0x2c/0x128 [msm]
[ 9.763632] sp : ffff800082dab460
[ 9.763666] Call trace:
[ 9.763668] lookup_vma+0x28/0xe0 [msm] (P)
[ 9.763688] get_vma_locked+0x2c/0x128 [msm]
[ 9.763706] msm_gem_get_and_pin_iova_range+0x68/0x11c [msm]
[ 9.763723] msm_gem_get_and_pin_iova+0x18/0x24 [msm]
[ 9.763740] msm_fbdev_driver_fbdev_probe+0xd0/0x258 [msm]
[ 9.763760] __drm_fb_helper_initial_config_and_unlock+0x288/0x528 [drm_kms_helper]
[ 9.763771] drm_fb_helper_initial_config+0x44/0x54 [drm_kms_helper]
[ 9.763779] drm_fbdev_client_hotplug+0x84/0xd4 [drm_client_lib]
[ 9.763782] drm_client_register+0x58/0x9c [drm]
[ 9.763806] drm_fbdev_client_setup+0xe8/0xcf0 [drm_client_lib]
[ 9.763809] drm_client_setup+0xb4/0xd8 [drm_client_lib]
[ 9.763811] msm_drm_kms_post_init+0x2c/0x3c [msm]
[ 9.763830] msm_drm_init+0x1a8/0x22c [msm]
[ 9.763848] msm_drm_bind+0x30/0x3c [msm]
[ 9.919273] try_to_bring_up_aggregate_device+0x168/0x1d4
[ 9.919283] __component_add+0xa4/0x170
[ 9.919286] component_add+0x14/0x20
[ 9.919288] msm_dp_display_probe_tail+0x4c/0xac [msm]
[ 9.919315] msm_dp_auxbus_done_probe+0x14/0x20 [msm]
[ 9.919335] dp_aux_ep_probe+0x4c/0xf0 [drm_dp_aux_bus]
[ 9.919341] really_probe+0xbc/0x298
[ 9.919345] __driver_probe_device+0x78/0x12c
[ 9.919348] driver_probe_device+0x40/0x160
[ 9.919350] __driver_attach+0x94/0x19c
[ 9.919353] bus_for_each_dev+0x74/0xd4
[ 9.919355] driver_attach+0x24/0x30
[ 9.919358] bus_add_driver+0xe4/0x208
[ 9.919360] driver_register+0x60/0x128
[ 9.919363] __dp_aux_dp_driver_register+0x24/0x30 [drm_dp_aux_bus]
[ 9.919365] atana33xc20_init+0x20/0x1000 [panel_samsung_atna33xc20]
[ 9.919370] do_one_initcall+0x6c/0x1b0
[ 9.919374] do_init_module+0x58/0x234
[ 9.919377] load_module+0x19cc/0x1bd4
[ 9.919380] init_module_from_file+0x84/0xc4
[ 9.919382] __arm64_sys_finit_module+0x1b8/0x2cc
[ 9.919384] invoke_syscall+0x48/0x110
[ 9.919389] el0_svc_common.constprop.0+0xc8/0xe8
[ 9.919393] do_el0_svc+0x20/0x2c
[ 9.919396] el0_svc+0x34/0xf0
[ 9.919401] el0t_64_sync_handler+0xa0/0xe4
[ 9.919403] el0t_64_sync+0x198/0x19c
[ 9.919407] Code: eb0000bf 54000480 d100a003 aa0303e2 (f8418c44)
[ 9.919410] ---[ end trace 0000000000000000 ]---
Patchwork: https://patchwork.freedesktop.org/pa
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
EDAC/i10nm: Skip DIMM enumeration on a disabled memory controller
When loading the i10nm_edac driver on some Intel Granite Rapids servers,
a call trace may appear as follows:
UBSAN: shift-out-of-bounds in drivers/edac/skx_common.c:453:16
shift exponent -66 is negative
...
__ubsan_handle_shift_out_of_bounds+0x1e3/0x390
skx_get_dimm_info.cold+0x47/0xd40 [skx_edac_common]
i10nm_get_dimm_config+0x23e/0x390 [i10nm_edac]
skx_register_mci+0x159/0x220 [skx_edac_common]
i10nm_init+0xcb0/0x1ff0 [i10nm_edac]
...
This occurs because some BIOS may disable a memory controller if there
aren't any memory DIMMs populated on this memory controller. The DIMMMTR
register of this disabled memory controller contains the invalid value
~0, resulting in the call trace above.
Fix this call trace by skipping DIMM enumeration on a disabled memory
controller. |
| In the Linux kernel, the following vulnerability has been resolved:
mailbox: zynqmp-ipi: Fix SGI cleanup on unbind
The driver incorrectly determines SGI vs SPI interrupts by checking IRQ
number < 16, which fails with dynamic IRQ allocation. During unbind,
this causes improper SGI cleanup leading to kernel crash.
Add explicit irq_type field to pdata for reliable identification of SGI
interrupts (type-2) and only clean up SGI resources when appropriate. |
| In the Linux kernel, the following vulnerability has been resolved:
ASoC: amd/sdw_utils: avoid NULL deref when devm_kasprintf() fails
devm_kasprintf() may return NULL on memory allocation failure,
but the debug message prints cpus->dai_name before checking it.
Move the dev_dbg() call after the NULL check to prevent potential
NULL pointer dereference. |
| In the Linux kernel, the following vulnerability has been resolved:
firmware: arm_scmi: Account for failed debug initialization
When the SCMI debug subsystem fails to initialize, the related debug root
will be missing, and the underlying descriptor will be NULL.
Handle this fault condition in the SCMI debug helpers that maintain
metrics counters. |
| In the Linux kernel, the following vulnerability has been resolved:
idpf: cleanup remaining SKBs in PTP flows
When the driver requests Tx timestamp value, one of the first steps is
to clone SKB using skb_get. It increases the reference counter for that
SKB to prevent unexpected freeing by another component.
However, there may be a case where the index is requested, SKB is
assigned and never consumed by PTP flows - for example due to reset during
running PTP apps.
Add a check in release timestamping function to verify if the SKB
assigned to Tx timestamp latch was freed, and release remaining SKBs. |
| In the Linux kernel, the following vulnerability has been resolved:
accel/qaic: Fix bootlog initialization ordering
As soon as we queue MHI buffers to receive the bootlog from the device,
we could be receiving data. Therefore all the resources needed to
process that data need to be setup prior to queuing the buffers.
We currently initialize some of the resources after queuing the buffers
which creates a race between the probe() and any data that comes back
from the device. If the uninitialized resources are accessed, we could
see page faults.
Fix the init ordering to close the race. |
| In the Linux kernel, the following vulnerability has been resolved:
pid: Add a judgment for ns null in pid_nr_ns
__task_pid_nr_ns
ns = task_active_pid_ns(current);
pid_nr_ns(rcu_dereference(*task_pid_ptr(task, type)), ns);
if (pid && ns->level <= pid->level) {
Sometimes null is returned for task_active_pid_ns. Then it will trigger kernel panic in pid_nr_ns.
For example:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000058
Mem abort info:
ESR = 0x0000000096000007
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x07: level 3 translation fault
Data abort info:
ISV = 0, ISS = 0x00000007, ISS2 = 0x00000000
CM = 0, WnR = 0, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
user pgtable: 4k pages, 39-bit VAs, pgdp=00000002175aa000
[0000000000000058] pgd=08000002175ab003, p4d=08000002175ab003, pud=08000002175ab003, pmd=08000002175be003, pte=0000000000000000
pstate: 834000c5 (Nzcv daIF +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : __task_pid_nr_ns+0x74/0xd0
lr : __task_pid_nr_ns+0x24/0xd0
sp : ffffffc08001bd10
x29: ffffffc08001bd10 x28: ffffffd4422b2000 x27: 0000000000000001
x26: ffffffd442821168 x25: ffffffd442821000 x24: 00000f89492eab31
x23: 00000000000000c0 x22: ffffff806f5693c0 x21: ffffff806f5693c0
x20: 0000000000000001 x19: 0000000000000000 x18: 0000000000000000
x17: 00000000529c6ef0 x16: 00000000529c6ef0 x15: 00000000023a1adc
x14: 0000000000000003 x13: 00000000007ef6d8 x12: 001167c391c78800
x11: 00ffffffffffffff x10: 0000000000000000 x9 : 0000000000000001
x8 : ffffff80816fa3c0 x7 : 0000000000000000 x6 : 49534d702d535449
x5 : ffffffc080c4c2c0 x4 : ffffffd43ee128c8 x3 : ffffffd43ee124dc
x2 : 0000000000000000 x1 : 0000000000000001 x0 : ffffff806f5693c0
Call trace:
__task_pid_nr_ns+0x74/0xd0
...
__handle_irq_event_percpu+0xd4/0x284
handle_irq_event+0x48/0xb0
handle_fasteoi_irq+0x160/0x2d8
generic_handle_domain_irq+0x44/0x60
gic_handle_irq+0x4c/0x114
call_on_irq_stack+0x3c/0x74
do_interrupt_handler+0x4c/0x84
el1_interrupt+0x34/0x58
el1h_64_irq_handler+0x18/0x24
el1h_64_irq+0x68/0x6c
account_kernel_stack+0x60/0x144
exit_task_stack_account+0x1c/0x80
do_exit+0x7e4/0xaf8
...
get_signal+0x7bc/0x8d8
do_notify_resume+0x128/0x828
el0_svc+0x6c/0x70
el0t_64_sync_handler+0x68/0xbc
el0t_64_sync+0x1a8/0x1ac
Code: 35fffe54 911a02a8 f9400108 b4000128 (b9405a69)
---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Oops: Fatal exception in interrupt |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: verify orphan file size is not too big
In principle orphan file can be arbitrarily large. However orphan replay
needs to traverse it all and we also pin all its buffers in memory. Thus
filesystems with absurdly large orphan files can lead to big amounts of
memory consumed. Limit orphan file size to a sane value and also use
kvmalloc() for allocating array of block descriptor structures to avoid
large order allocations for sane but large orphan files. |
| In the Linux kernel, the following vulnerability has been resolved:
mailbox: zynqmp-ipi: Fix out-of-bounds access in mailbox cleanup loop
The cleanup loop was starting at the wrong array index, causing
out-of-bounds access.
Start the loop at the correct index for zero-indexed arrays to prevent
accessing memory beyond the allocated array bounds. |
| In the Linux kernel, the following vulnerability has been resolved:
x86/kvm: Force legacy PCI hole to UC when overriding MTRRs for TDX/SNP
When running as an SNP or TDX guest under KVM, force the legacy PCI hole,
i.e. memory between Top of Lower Usable DRAM and 4GiB, to be mapped as UC
via a forced variable MTRR range.
In most KVM-based setups, legacy devices such as the HPET and TPM are
enumerated via ACPI. ACPI enumeration includes a Memory32Fixed entry, and
optionally a SystemMemory descriptor for an OperationRegion, e.g. if the
device needs to be accessed via a Control Method.
If a SystemMemory entry is present, then the kernel's ACPI driver will
auto-ioremap the region so that it can be accessed at will. However, the
ACPI spec doesn't provide a way to enumerate the memory type of
SystemMemory regions, i.e. there's no way to tell software that a region
must be mapped as UC vs. WB, etc. As a result, Linux's ACPI driver always
maps SystemMemory regions using ioremap_cache(), i.e. as WB on x86.
The dedicated device drivers however, e.g. the HPET driver and TPM driver,
want to map their associated memory as UC or WC, as accessing PCI devices
using WB is unsupported.
On bare metal and non-CoCO, the conflicting requirements "work" as firmware
configures the PCI hole (and other device memory) to be UC in the MTRRs.
So even though the ACPI mappings request WB, they are forced to UC- in the
kernel's tracking due to the kernel properly handling the MTRR overrides,
and thus are compatible with the drivers' requested WC/UC-.
With force WB MTRRs on SNP and TDX guests, the ACPI mappings get their
requested WB if the ACPI mappings are established before the dedicated
driver code attempts to initialize the device. E.g. if acpi_init()
runs before the corresponding device driver is probed, ACPI's WB mapping
will "win", and result in the driver's ioremap() failing because the
existing WB mapping isn't compatible with the requested WC/UC-.
E.g. when a TPM is emulated by the hypervisor (ignoring the security
implications of relying on what is allegedly an untrusted entity to store
measurements), the TPM driver will request UC and fail:
[ 1.730459] ioremap error for 0xfed40000-0xfed45000, requested 0x2, got 0x0
[ 1.732780] tpm_tis MSFT0101:00: probe with driver tpm_tis failed with error -12
Note, the '0x2' and '0x0' values refer to "enum page_cache_mode", not x86's
memtypes (which frustratingly are an almost pure inversion; 2 == WB, 0 == UC).
E.g. tracing mapping requests for TPM TIS yields:
Mapping TPM TIS with req_type = 0
WARNING: CPU: 22 PID: 1 at arch/x86/mm/pat/memtype.c:530 memtype_reserve+0x2ab/0x460
Modules linked in:
CPU: 22 UID: 0 PID: 1 Comm: swapper/0 Tainted: G W 6.16.0-rc7+ #2 VOLUNTARY
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/29/2025
RIP: 0010:memtype_reserve+0x2ab/0x460
__ioremap_caller+0x16d/0x3d0
ioremap_cache+0x17/0x30
x86_acpi_os_ioremap+0xe/0x20
acpi_os_map_iomem+0x1f3/0x240
acpi_os_map_memory+0xe/0x20
acpi_ex_system_memory_space_handler+0x273/0x440
acpi_ev_address_space_dispatch+0x176/0x4c0
acpi_ex_access_region+0x2ad/0x530
acpi_ex_field_datum_io+0xa2/0x4f0
acpi_ex_extract_from_field+0x296/0x3e0
acpi_ex_read_data_from_field+0xd1/0x460
acpi_ex_resolve_node_to_value+0x2ee/0x530
acpi_ex_resolve_to_value+0x1f2/0x540
acpi_ds_evaluate_name_path+0x11b/0x190
acpi_ds_exec_end_op+0x456/0x960
acpi_ps_parse_loop+0x27a/0xa50
acpi_ps_parse_aml+0x226/0x600
acpi_ps_execute_method+0x172/0x3e0
acpi_ns_evaluate+0x175/0x5f0
acpi_evaluate_object+0x213/0x490
acpi_evaluate_integer+0x6d/0x140
acpi_bus_get_status+0x93/0x150
acpi_add_single_object+0x43a/0x7c0
acpi_bus_check_add+0x149/0x3a0
acpi_bus_check_add_1+0x16/0x30
acpi_ns_walk_namespace+0x22c/0x360
acpi_walk_namespace+0x15c/0x170
acpi_bus_scan+0x1dd/0x200
acpi_scan_init+0xe5/0x2b0
acpi_init+0x264/0x5b0
do_one_i
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
cpufreq: intel_pstate: Fix object lifecycle issue in update_qos_request()
The cpufreq_cpu_put() call in update_qos_request() takes place too early
because the latter subsequently calls freq_qos_update_request() that
indirectly accesses the policy object in question through the QoS request
object passed to it.
Fortunately, update_qos_request() is called under intel_pstate_driver_lock,
so this issue does not matter for changing the intel_pstate operation
mode, but it theoretically can cause a crash to occur on CPU device hot
removal (which currently can only happen in virt, but it is formally
supported nevertheless).
Address this issue by modifying update_qos_request() to drop the
reference to the policy later. |
