| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
exfat: fix divide-by-zero in exfat_allocate_bitmap
The variable max_ra_count can be 0 in exfat_allocate_bitmap(),
which causes a divide-by-zero error in the subsequent modulo operation
(i % max_ra_count), leading to a system crash.
When max_ra_count is 0, it means that readahead is not used. This patch
load the bitmap without readahead. |
| In the Linux kernel, the following vulnerability has been resolved:
thunderbolt: Fix use-after-free in tb_dp_dprx_work
The original code relies on cancel_delayed_work() in tb_dp_dprx_stop(),
which does not ensure that the delayed work item tunnel->dprx_work has
fully completed if it was already running. This leads to use-after-free
scenarios where tb_tunnel is deallocated by tb_tunnel_put(), while
tunnel->dprx_work remains active and attempts to dereference tb_tunnel
in tb_dp_dprx_work().
A typical race condition is illustrated below:
CPU 0 | CPU 1
tb_dp_tunnel_active() |
tb_deactivate_and_free_tunnel()| tb_dp_dprx_start()
tb_tunnel_deactivate() | queue_delayed_work()
tb_dp_activate() |
tb_dp_dprx_stop() | tb_dp_dprx_work() //delayed worker
cancel_delayed_work() |
tb_tunnel_put(tunnel); |
| tunnel = container_of(...); //UAF
| tunnel-> //UAF
Replacing cancel_delayed_work() with cancel_delayed_work_sync() is
not feasible as it would introduce a deadlock: both tb_dp_dprx_work()
and the cleanup path acquire tb->lock, and cancel_delayed_work_sync()
would wait indefinitely for the work item that cannot proceed.
Instead, implement proper reference counting:
- If cancel_delayed_work() returns true (work is pending), we release
the reference in the stop function.
- If it returns false (work is executing or already completed), the
reference is released in delayed work function itself.
This ensures the tb_tunnel remains valid during work item execution
while preventing memory leaks.
This bug was found by static analysis. |
| In the Linux kernel, the following vulnerability has been resolved:
media: v4l2-core: Fix a potential resource leak in v4l2_fwnode_parse_link()
If fwnode_graph_get_remote_endpoint() fails, 'fwnode' is known to be NULL,
so fwnode_handle_put() is a no-op.
Release the reference taken from a previous fwnode_graph_get_port_parent()
call instead.
Also handle fwnode_graph_get_port_parent() failures.
In order to fix these issues, add an error handling path to the function
and the needed gotos. |
| In the Linux kernel, the following vulnerability has been resolved:
backlight: led-bl: Add devlink to supplier LEDs
LED Backlight is a consumer of one or multiple LED class devices, but
devlink is currently unable to create correct supplier-producer links when
the supplier is a class device. It creates instead a link where the
supplier is the parent of the expected device.
One consequence is that removal order is not correctly enforced.
Issues happen for example with the following sections in a device tree
overlay:
// An LED driver chip
pca9632@62 {
compatible = "nxp,pca9632";
reg = <0x62>;
// ...
addon_led_pwm: led-pwm@3 {
reg = <3>;
label = "addon:led:pwm";
};
};
backlight-addon {
compatible = "led-backlight";
leds = <&addon_led_pwm>;
brightness-levels = <255>;
default-brightness-level = <255>;
};
In this example, the devlink should be created between the backlight-addon
(consumer) and the pca9632@62 (supplier). Instead it is created between the
backlight-addon (consumer) and the parent of the pca9632@62, which is
typically the I2C bus adapter.
On removal of the above overlay, the LED driver can be removed before the
backlight device, resulting in:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
...
Call trace:
led_put+0xe0/0x140
devm_led_release+0x6c/0x98
Another way to reproduce the bug without any device tree overlays is
unbinding the LED class device (pca9632@62) before unbinding the consumer
(backlight-addon):
echo 11-0062 >/sys/bus/i2c/drivers/leds-pca963x/unbind
echo ...backlight-dock >/sys/bus/platform/drivers/led-backlight/unbind
Fix by adding a devlink between the consuming led-backlight device and the
supplying LED device, as other drivers and subsystems do as well. |
| In the Linux kernel, the following vulnerability has been resolved:
net/9p: Fix buffer overflow in USB transport layer
A buffer overflow vulnerability exists in the USB 9pfs transport layer
where inconsistent size validation between packet header parsing and
actual data copying allows a malicious USB host to overflow heap buffers.
The issue occurs because:
- usb9pfs_rx_header() validates only the declared size in packet header
- usb9pfs_rx_complete() uses req->actual (actual received bytes) for
memcpy
This allows an attacker to craft packets with small declared size
(bypassing validation) but large actual payload (triggering overflow
in memcpy).
Add validation in usb9pfs_rx_complete() to ensure req->actual does not
exceed the buffer capacity before copying data. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/vmwgfx: Fix a null-ptr access in the cursor snooper
Check that the resource which is converted to a surface exists before
trying to use the cursor snooper on it.
vmw_cmd_res_check allows explicit invalid (SVGA3D_INVALID_ID) identifiers
because some svga commands accept SVGA3D_INVALID_ID to mean "no surface",
unfortunately functions that accept the actual surfaces as objects might
(and in case of the cursor snooper, do not) be able to handle null
objects. Make sure that we validate not only the identifier (via the
vmw_cmd_res_check) but also check that the actual resource exists before
trying to do something with it.
Fixes unchecked null-ptr reference in the snooping code. |
| In the Linux kernel, the following vulnerability has been resolved:
serial: sc16is7xx: setup GPIO controller later in probe
The GPIO controller component of the sc16is7xx driver is setup too
early, which can result in a race condition where another device tries
to utilise the GPIO lines before the sc16is7xx device has finished
initialising.
This issue manifests itself as an Oops when the GPIO lines are configured:
Unable to handle kernel read from unreadable memory at virtual address
...
pc : sc16is7xx_gpio_direction_output+0x68/0x108 [sc16is7xx]
lr : sc16is7xx_gpio_direction_output+0x4c/0x108 [sc16is7xx]
...
Call trace:
sc16is7xx_gpio_direction_output+0x68/0x108 [sc16is7xx]
gpiod_direction_output_raw_commit+0x64/0x318
gpiod_direction_output+0xb0/0x170
create_gpio_led+0xec/0x198
gpio_led_probe+0x16c/0x4f0
platform_drv_probe+0x5c/0xb0
really_probe+0xe8/0x448
driver_probe_device+0xe8/0x138
__device_attach_driver+0x94/0x118
bus_for_each_drv+0x8c/0xe0
__device_attach+0x100/0x1b8
device_initial_probe+0x28/0x38
bus_probe_device+0xa4/0xb0
deferred_probe_work_func+0x90/0xe0
process_one_work+0x1c4/0x480
worker_thread+0x54/0x430
kthread+0x138/0x150
ret_from_fork+0x10/0x1c
This patch moves the setup of the GPIO controller functions to later in the
probe function, ensuring the sc16is7xx device has already finished
initialising by the time other devices try to make use of the GPIO lines.
The error handling has also been reordered to reflect the new
initialisation order. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Add preempt_count_{sub,add} into btf id deny list
The recursion check in __bpf_prog_enter* and __bpf_prog_exit*
leave preempt_count_{sub,add} unprotected. When attaching trampoline to
them we get panic as follows,
[ 867.843050] BUG: TASK stack guard page was hit at 0000000009d325cf (stack is 0000000046a46a15..00000000537e7b28)
[ 867.843064] stack guard page: 0000 [#1] PREEMPT SMP NOPTI
[ 867.843067] CPU: 8 PID: 11009 Comm: trace Kdump: loaded Not tainted 6.2.0+ #4
[ 867.843100] Call Trace:
[ 867.843101] <TASK>
[ 867.843104] asm_exc_int3+0x3a/0x40
[ 867.843108] RIP: 0010:preempt_count_sub+0x1/0xa0
[ 867.843135] __bpf_prog_enter_recur+0x17/0x90
[ 867.843148] bpf_trampoline_6442468108_0+0x2e/0x1000
[ 867.843154] ? preempt_count_sub+0x1/0xa0
[ 867.843157] preempt_count_sub+0x5/0xa0
[ 867.843159] ? migrate_enable+0xac/0xf0
[ 867.843164] __bpf_prog_exit_recur+0x2d/0x40
[ 867.843168] bpf_trampoline_6442468108_0+0x55/0x1000
...
[ 867.843788] preempt_count_sub+0x5/0xa0
[ 867.843793] ? migrate_enable+0xac/0xf0
[ 867.843829] __bpf_prog_exit_recur+0x2d/0x40
[ 867.843837] BUG: IRQ stack guard page was hit at 0000000099bd8228 (stack is 00000000b23e2bc4..000000006d95af35)
[ 867.843841] BUG: IRQ stack guard page was hit at 000000005ae07924 (stack is 00000000ffd69623..0000000014eb594c)
[ 867.843843] BUG: IRQ stack guard page was hit at 00000000028320f0 (stack is 00000000034b6438..0000000078d1bcec)
[ 867.843842] bpf_trampoline_6442468108_0+0x55/0x1000
...
That is because in __bpf_prog_exit_recur, the preempt_count_{sub,add} are
called after prog->active is decreased.
Fixing this by adding these two functions into btf ids deny list. |
| In the Linux kernel, the following vulnerability has been resolved:
net: hns3: fix deadlock issue when externel_lb and reset are executed together
When externel_lb and reset are executed together, a deadlock may
occur:
[ 3147.217009] INFO: task kworker/u321:0:7 blocked for more than 120 seconds.
[ 3147.230483] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 3147.238999] task:kworker/u321:0 state:D stack: 0 pid: 7 ppid: 2 flags:0x00000008
[ 3147.248045] Workqueue: hclge hclge_service_task [hclge]
[ 3147.253957] Call trace:
[ 3147.257093] __switch_to+0x7c/0xbc
[ 3147.261183] __schedule+0x338/0x6f0
[ 3147.265357] schedule+0x50/0xe0
[ 3147.269185] schedule_preempt_disabled+0x18/0x24
[ 3147.274488] __mutex_lock.constprop.0+0x1d4/0x5dc
[ 3147.279880] __mutex_lock_slowpath+0x1c/0x30
[ 3147.284839] mutex_lock+0x50/0x60
[ 3147.288841] rtnl_lock+0x20/0x2c
[ 3147.292759] hclge_reset_prepare+0x68/0x90 [hclge]
[ 3147.298239] hclge_reset_subtask+0x88/0xe0 [hclge]
[ 3147.303718] hclge_reset_service_task+0x84/0x120 [hclge]
[ 3147.309718] hclge_service_task+0x2c/0x70 [hclge]
[ 3147.315109] process_one_work+0x1d0/0x490
[ 3147.319805] worker_thread+0x158/0x3d0
[ 3147.324240] kthread+0x108/0x13c
[ 3147.328154] ret_from_fork+0x10/0x18
In externel_lb process, the hns3 driver call napi_disable()
first, then the reset happen, then the restore process of the
externel_lb will fail, and will not call napi_enable(). When
doing externel_lb again, napi_disable() will be double call,
cause a deadlock of rtnl_lock().
This patch use the HNS3_NIC_STATE_DOWN state to protect the
calling of napi_disable() and napi_enable() in externel_lb
process, just as the usage in ndo_stop() and ndo_start(). |
| In the Linux kernel, the following vulnerability has been resolved:
drm/msm/dpu: Disallow unallocated resources to be returned
In the event that the topology requests resources that have not been
created by the system (because they are typically not represented in
dpu_mdss_cfg ^1), the resource(s) in global_state (in this case DSC
blocks, until their allocation/assignment is being sanity-checked in
"drm/msm/dpu: Reject topologies for which no DSC blocks are available")
remain NULL but will still be returned out of
dpu_rm_get_assigned_resources, where the caller expects to get an array
containing num_blks valid pointers (but instead gets these NULLs).
To prevent this from happening, where null-pointer dereferences
typically result in a hard-to-debug platform lockup, num_blks shouldn't
increase past NULL blocks and will print an error and break instead.
After all, max_blks represents the static size of the maximum number of
blocks whereas the actual amount varies per platform.
^1: which can happen after a git rebase ended up moving additions to
_dpu_cfg to a different struct which has the same patch context.
Patchwork: https://patchwork.freedesktop.org/patch/517636/ |
| In the Linux kernel, the following vulnerability has been resolved:
iommu/amd: Improve page fault error reporting
If IOMMU domain for device group is not setup properly then we may hit
IOMMU page fault. Current page fault handler assumes that domain is
always setup and it will hit NULL pointer derefence (see below sample log).
Lets check whether domain is setup or not and log appropriate message.
Sample log:
----------
amdgpu 0000:00:01.0: amdgpu: SE 1, SH per SE 1, CU per SH 8, active_cu_number 6
BUG: kernel NULL pointer dereference, address: 0000000000000058
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 2 PID: 56 Comm: irq/24-AMD-Vi Not tainted 6.2.0-rc2+ #89
Hardware name: xxx
RIP: 0010:report_iommu_fault+0x11/0x90
[...]
Call Trace:
<TASK>
amd_iommu_int_thread+0x60c/0x760
? __pfx_irq_thread_fn+0x10/0x10
irq_thread_fn+0x1f/0x60
irq_thread+0xea/0x1a0
? preempt_count_add+0x6a/0xa0
? __pfx_irq_thread_dtor+0x10/0x10
? __pfx_irq_thread+0x10/0x10
kthread+0xe9/0x110
? __pfx_kthread+0x10/0x10
ret_from_fork+0x2c/0x50
</TASK>
[joro: Edit commit message] |
| In the Linux kernel, the following vulnerability has been resolved:
USB: usbtmc: Fix direction for 0-length ioctl control messages
The syzbot fuzzer found a problem in the usbtmc driver: When a user
submits an ioctl for a 0-length control transfer, the driver does not
check that the direction is set to OUT:
------------[ cut here ]------------
usb 3-1: BOGUS control dir, pipe 80000b80 doesn't match bRequestType fd
WARNING: CPU: 0 PID: 5100 at drivers/usb/core/urb.c:411 usb_submit_urb+0x14a7/0x1880 drivers/usb/core/urb.c:411
Modules linked in:
CPU: 0 PID: 5100 Comm: syz-executor428 Not tainted 6.3.0-syzkaller-12049-g58390c8ce1bd #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
RIP: 0010:usb_submit_urb+0x14a7/0x1880 drivers/usb/core/urb.c:411
Code: 7c 24 40 e8 1b 13 5c fb 48 8b 7c 24 40 e8 21 1d f0 fe 45 89 e8 44 89 f1 4c 89 e2 48 89 c6 48 c7 c7 e0 b5 fc 8a e8 19 c8 23 fb <0f> 0b e9 9f ee ff ff e8 ed 12 5c fb 0f b6 1d 12 8a 3c 08 31 ff 41
RSP: 0018:ffffc90003d2fb00 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff8880789e9058 RCX: 0000000000000000
RDX: ffff888029593b80 RSI: ffffffff814c1447 RDI: 0000000000000001
RBP: ffff88801ea742f8 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff88802915e528
R13: 00000000000000fd R14: 0000000080000b80 R15: ffff8880222b3100
FS: 0000555556ca63c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9ef4d18150 CR3: 0000000073e5b000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
usb_start_wait_urb+0x101/0x4b0 drivers/usb/core/message.c:58
usb_internal_control_msg drivers/usb/core/message.c:102 [inline]
usb_control_msg+0x320/0x4a0 drivers/usb/core/message.c:153
usbtmc_ioctl_request drivers/usb/class/usbtmc.c:1954 [inline]
usbtmc_ioctl+0x1b3d/0x2840 drivers/usb/class/usbtmc.c:2097
To fix this, we must override the direction in the bRequestType field
of the control request structure when the length is 0. |
| In the Linux kernel, the following vulnerability has been resolved:
PCI: Fix pci_device_is_present() for VFs by checking PF
pci_device_is_present() previously didn't work for VFs because it reads the
Vendor and Device ID, which are 0xffff for VFs, which looks like they
aren't present. Check the PF instead.
Wei Gong reported that if virtio I/O is in progress when the driver is
unbound or "0" is written to /sys/.../sriov_numvfs, the virtio I/O
operation hangs, which may result in output like this:
task:bash state:D stack: 0 pid: 1773 ppid: 1241 flags:0x00004002
Call Trace:
schedule+0x4f/0xc0
blk_mq_freeze_queue_wait+0x69/0xa0
blk_mq_freeze_queue+0x1b/0x20
blk_cleanup_queue+0x3d/0xd0
virtblk_remove+0x3c/0xb0 [virtio_blk]
virtio_dev_remove+0x4b/0x80
...
device_unregister+0x1b/0x60
unregister_virtio_device+0x18/0x30
virtio_pci_remove+0x41/0x80
pci_device_remove+0x3e/0xb0
This happened because pci_device_is_present(VF) returned "false" in
virtio_pci_remove(), so it called virtio_break_device(). The broken vq
meant that vring_interrupt() skipped the vq.callback() that would have
completed the virtio I/O operation via virtblk_done().
[bhelgaas: commit log, simplify to always use pci_physfn(), add stable tag] |
| In the Linux kernel, the following vulnerability has been resolved:
usb: typec: ucsi: fix use-after-free caused by uec->work
The delayed work uec->work is scheduled in gaokun_ucsi_probe()
but never properly canceled in gaokun_ucsi_remove(). This creates
use-after-free scenarios where the ucsi and gaokun_ucsi structure
are freed after ucsi_destroy() completes execution, while the
gaokun_ucsi_register_worker() might be either currently executing
or still pending in the work queue. The already-freed gaokun_ucsi
or ucsi structure may then be accessed.
Furthermore, the race window is 3 seconds, which is sufficiently
long to make this bug easily reproducible. The following is the
trace captured by KASAN:
==================================================================
BUG: KASAN: slab-use-after-free in __run_timers+0x5ec/0x630
Write of size 8 at addr ffff00000ec28cc8 by task swapper/0/0
...
Call trace:
show_stack+0x18/0x24 (C)
dump_stack_lvl+0x78/0x90
print_report+0x114/0x580
kasan_report+0xa4/0xf0
__asan_report_store8_noabort+0x20/0x2c
__run_timers+0x5ec/0x630
run_timer_softirq+0xe8/0x1cc
handle_softirqs+0x294/0x720
__do_softirq+0x14/0x20
____do_softirq+0x10/0x1c
call_on_irq_stack+0x30/0x48
do_softirq_own_stack+0x1c/0x28
__irq_exit_rcu+0x27c/0x364
irq_exit_rcu+0x10/0x1c
el1_interrupt+0x40/0x60
el1h_64_irq_handler+0x18/0x24
el1h_64_irq+0x6c/0x70
arch_local_irq_enable+0x4/0x8 (P)
do_idle+0x334/0x458
cpu_startup_entry+0x60/0x70
rest_init+0x158/0x174
start_kernel+0x2f8/0x394
__primary_switched+0x8c/0x94
Allocated by task 72 on cpu 0 at 27.510341s:
kasan_save_stack+0x2c/0x54
kasan_save_track+0x24/0x5c
kasan_save_alloc_info+0x40/0x54
__kasan_kmalloc+0xa0/0xb8
__kmalloc_node_track_caller_noprof+0x1c0/0x588
devm_kmalloc+0x7c/0x1c8
gaokun_ucsi_probe+0xa0/0x840 auxiliary_bus_probe+0x94/0xf8
really_probe+0x17c/0x5b8
__driver_probe_device+0x158/0x2c4
driver_probe_device+0x10c/0x264
__device_attach_driver+0x168/0x2d0
bus_for_each_drv+0x100/0x188
__device_attach+0x174/0x368
device_initial_probe+0x14/0x20
bus_probe_device+0x120/0x150
device_add+0xb3c/0x10fc
__auxiliary_device_add+0x88/0x130
...
Freed by task 73 on cpu 1 at 28.910627s:
kasan_save_stack+0x2c/0x54
kasan_save_track+0x24/0x5c
__kasan_save_free_info+0x4c/0x74
__kasan_slab_free+0x60/0x8c
kfree+0xd4/0x410
devres_release_all+0x140/0x1f0
device_unbind_cleanup+0x20/0x190
device_release_driver_internal+0x344/0x460
device_release_driver+0x18/0x24
bus_remove_device+0x198/0x274
device_del+0x310/0xa84
...
The buggy address belongs to the object at ffff00000ec28c00
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 200 bytes inside of
freed 512-byte region
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4ec28
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x3fffe0000000040(head|node=0|zone=0|lastcpupid=0x1ffff)
page_type: f5(slab)
raw: 03fffe0000000040 ffff000008801c80 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000
head: 03fffe0000000040 ffff000008801c80 dead000000000122 0000000000000000
head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000
head: 03fffe0000000002 fffffdffc03b0a01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff00000ec28b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff00000ec28c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff00000ec28c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff00000ec28d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff00000ec28d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
================================================================
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: starfive - Correctly handle return of sg_nents_for_len
The return value of sg_nents_for_len was assigned to an unsigned long
in starfive_hash_digest, causing negative error codes to be converted
to large positive integers.
Add error checking for sg_nents_for_len and return immediately on
failure to prevent potential buffer overflows. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: ufs: core: Fix invalid probe error return value
After DME Link Startup, the error return value is set to the MIPI UniPro
GenericErrorCode which can be 0 (SUCCESS) or 1 (FAILURE). Upon failure
during driver probe, the error code 1 is propagated back to the driver
probe function which must return a negative value to indicate an error,
but 1 is not negative, so the probe is considered to be successful even
though it failed. Subsequently, removing the driver results in an oops
because it is not in a valid state.
This happens because none of the callers of ufshcd_init() expect a
non-negative error code.
Fix the return value and documentation to match actual usage. |
| In the Linux kernel, the following vulnerability has been resolved:
xtensa: simdisk: add input size check in proc_write_simdisk
A malicious user could pass an arbitrarily bad value
to memdup_user_nul(), potentially causing kernel crash.
This follows the same pattern as commit ee76746387f6
("netdevsim: prevent bad user input in nsim_dev_health_break_write()") |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: Fix kfd process ref leaking when userptr unmapping
kfd_lookup_process_by_pid hold the kfd process reference to ensure it
doesn't get destroyed while sending the segfault event to user space.
Calling kfd_lookup_process_by_pid as function parameter leaks the kfd
process refcount and miss the NULL pointer check if app process is
already destroyed. |
| In the Linux kernel, the following vulnerability has been resolved:
media: v4l2-subdev: Fix alloc failure check in v4l2_subdev_call_state_try()
v4l2_subdev_call_state_try() macro allocates a subdev state with
__v4l2_subdev_state_alloc(), but does not check the returned value. If
__v4l2_subdev_state_alloc fails, it returns an ERR_PTR, and that would
cause v4l2_subdev_call_state_try() to crash.
Add proper error handling to v4l2_subdev_call_state_try(). |
| 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--- |
