| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
tty: serial: sh-sci: fix RSCI FIFO overrun handling
The receive error handling code is shared between RSCI and all other
SCIF port types, but the RSCI overrun_reg is specified as a memory
offset, while for other SCIF types it is an enum value used to index
into the sci_port_params->regs array, as mentioned above the
sci_serial_in() function.
For RSCI, the overrun_reg is CSR (0x48), causing the sci_getreg() call
inside the sci_handle_fifo_overrun() function to index outside the
bounds of the regs array, which currently has a size of 20, as specified
by SCI_NR_REGS.
Because of this, we end up accessing memory outside of RSCI's
rsci_port_params structure, which, when interpreted as a plat_sci_reg,
happens to have a non-zero size, causing the following WARN when
sci_serial_in() is called, as the accidental size does not match the
supported register sizes.
The existence of the overrun_reg needs to be checked because
SCIx_SH3_SCIF_REGTYPE has overrun_reg set to SCLSR, but SCLSR is not
present in the regs array.
Avoid calling sci_getreg() for port types which don't use standard
register handling.
Use the ops->read_reg() and ops->write_reg() functions to properly read
and write registers for RSCI, and change the type of the status variable
to accommodate the 32-bit CSR register.
sci_getreg() and sci_serial_in() are also called with overrun_reg in the
sci_mpxed_interrupt() interrupt handler, but that code path is not used
for RSCI, as it does not have a muxed interrupt.
------------[ cut here ]------------
Invalid register access
WARNING: CPU: 0 PID: 0 at drivers/tty/serial/sh-sci.c:522 sci_serial_in+0x38/0xac
Modules linked in: renesas_usbhs at24 rzt2h_adc industrialio_adc sha256 cfg80211 bluetooth ecdh_generic ecc rfkill fuse drm backlight ipv6
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.17.0-rc1+ #30 PREEMPT
Hardware name: Renesas RZ/T2H EVK Board based on r9a09g077m44 (DT)
pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : sci_serial_in+0x38/0xac
lr : sci_serial_in+0x38/0xac
sp : ffff800080003e80
x29: ffff800080003e80 x28: ffff800082195b80 x27: 000000000000000d
x26: ffff8000821956d0 x25: 0000000000000000 x24: ffff800082195b80
x23: ffff000180e0d800 x22: 0000000000000010 x21: 0000000000000000
x20: 0000000000000010 x19: ffff000180e72000 x18: 000000000000000a
x17: ffff8002bcee7000 x16: ffff800080000000 x15: 0720072007200720
x14: 0720072007200720 x13: 0720072007200720 x12: 0720072007200720
x11: 0000000000000058 x10: 0000000000000018 x9 : ffff8000821a6a48
x8 : 0000000000057fa8 x7 : 0000000000000406 x6 : ffff8000821fea48
x5 : ffff00033ef88408 x4 : ffff8002bcee7000 x3 : ffff800082195b80
x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff800082195b80
Call trace:
sci_serial_in+0x38/0xac (P)
sci_handle_fifo_overrun.isra.0+0x70/0x134
sci_er_interrupt+0x50/0x39c
__handle_irq_event_percpu+0x48/0x140
handle_irq_event+0x44/0xb0
handle_fasteoi_irq+0xf4/0x1a0
handle_irq_desc+0x34/0x58
generic_handle_domain_irq+0x1c/0x28
gic_handle_irq+0x4c/0x140
call_on_irq_stack+0x30/0x48
do_interrupt_handler+0x80/0x84
el1_interrupt+0x34/0x68
el1h_64_irq_handler+0x18/0x24
el1h_64_irq+0x6c/0x70
default_idle_call+0x28/0x58 (P)
do_idle+0x1f8/0x250
cpu_startup_entry+0x34/0x3c
rest_init+0xd8/0xe0
console_on_rootfs+0x0/0x6c
__primary_switched+0x88/0x90
---[ end trace 0000000000000000 ]--- |
| In the Linux kernel, the following vulnerability has been resolved:
media: pci: mg4b: fix uninitialized iio scan data
Fix potential leak of uninitialized stack data to userspace by ensuring
that the `scan` structure is zeroed before use. |
| In the Linux kernel, the following vulnerability has been resolved:
fuse: fix livelock in synchronous file put from fuseblk workers
I observed a hang when running generic/323 against a fuseblk server.
This test opens a file, initiates a lot of AIO writes to that file
descriptor, and closes the file descriptor before the writes complete.
Unsurprisingly, the AIO exerciser threads are mostly stuck waiting for
responses from the fuseblk server:
# cat /proc/372265/task/372313/stack
[<0>] request_wait_answer+0x1fe/0x2a0 [fuse]
[<0>] __fuse_simple_request+0xd3/0x2b0 [fuse]
[<0>] fuse_do_getattr+0xfc/0x1f0 [fuse]
[<0>] fuse_file_read_iter+0xbe/0x1c0 [fuse]
[<0>] aio_read+0x130/0x1e0
[<0>] io_submit_one+0x542/0x860
[<0>] __x64_sys_io_submit+0x98/0x1a0
[<0>] do_syscall_64+0x37/0xf0
[<0>] entry_SYSCALL_64_after_hwframe+0x4b/0x53
But the /weird/ part is that the fuseblk server threads are waiting for
responses from itself:
# cat /proc/372210/task/372232/stack
[<0>] request_wait_answer+0x1fe/0x2a0 [fuse]
[<0>] __fuse_simple_request+0xd3/0x2b0 [fuse]
[<0>] fuse_file_put+0x9a/0xd0 [fuse]
[<0>] fuse_release+0x36/0x50 [fuse]
[<0>] __fput+0xec/0x2b0
[<0>] task_work_run+0x55/0x90
[<0>] syscall_exit_to_user_mode+0xe9/0x100
[<0>] do_syscall_64+0x43/0xf0
[<0>] entry_SYSCALL_64_after_hwframe+0x4b/0x53
The fuseblk server is fuse2fs so there's nothing all that exciting in
the server itself. So why is the fuse server calling fuse_file_put?
The commit message for the fstest sheds some light on that:
"By closing the file descriptor before calling io_destroy, you pretty
much guarantee that the last put on the ioctx will be done in interrupt
context (during I/O completion).
Aha. AIO fgets a new struct file from the fd when it queues the ioctx.
The completion of the FUSE_WRITE command from userspace causes the fuse
server to call the AIO completion function. The completion puts the
struct file, queuing a delayed fput to the fuse server task. When the
fuse server task returns to userspace, it has to run the delayed fput,
which in the case of a fuseblk server, it does synchronously.
Sending the FUSE_RELEASE command sychronously from fuse server threads
is a bad idea because a client program can initiate enough simultaneous
AIOs such that all the fuse server threads end up in delayed_fput, and
now there aren't any threads left to handle the queued fuse commands.
Fix this by only using asynchronous fputs when closing files, and leave
a comment explaining why. |
| In the Linux kernel, the following vulnerability has been resolved:
pidfs: validate extensible ioctls
Validate extensible ioctls stricter than we do now. |
| 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:
media: iris: fix module removal if firmware download failed
Fix remove if firmware failed to load:
qcom-iris aa00000.video-codec: Direct firmware load for qcom/vpu/vpu33_p4.mbn failed with error -2
qcom-iris aa00000.video-codec: firmware download failed
qcom-iris aa00000.video-codec: core init failed
then:
$ echo aa00000.video-codec > /sys/bus/platform/drivers/qcom-iris/unbind
Triggers:
genpd genpd:1:aa00000.video-codec: Runtime PM usage count underflow!
------------[ cut here ]------------
video_cc_mvs0_clk already disabled
WARNING: drivers/clk/clk.c:1206 at clk_core_disable+0xa4/0xac, CPU#1: sh/542
<snip>
pc : clk_core_disable+0xa4/0xac
lr : clk_core_disable+0xa4/0xac
<snip>
Call trace:
clk_core_disable+0xa4/0xac (P)
clk_disable+0x30/0x4c
iris_disable_unprepare_clock+0x20/0x48 [qcom_iris]
iris_vpu_power_off_hw+0x48/0x58 [qcom_iris]
iris_vpu33_power_off_hardware+0x44/0x230 [qcom_iris]
iris_vpu_power_off+0x34/0x84 [qcom_iris]
iris_core_deinit+0x44/0xc8 [qcom_iris]
iris_remove+0x20/0x48 [qcom_iris]
platform_remove+0x20/0x30
device_remove+0x4c/0x80
<snip>
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
video_cc_mvs0_clk already unprepared
WARNING: drivers/clk/clk.c:1065 at clk_core_unprepare+0xf0/0x110, CPU#2: sh/542
<snip>
pc : clk_core_unprepare+0xf0/0x110
lr : clk_core_unprepare+0xf0/0x110
<snip>
Call trace:
clk_core_unprepare+0xf0/0x110 (P)
clk_unprepare+0x2c/0x44
iris_disable_unprepare_clock+0x28/0x48 [qcom_iris]
iris_vpu_power_off_hw+0x48/0x58 [qcom_iris]
iris_vpu33_power_off_hardware+0x44/0x230 [qcom_iris]
iris_vpu_power_off+0x34/0x84 [qcom_iris]
iris_core_deinit+0x44/0xc8 [qcom_iris]
iris_remove+0x20/0x48 [qcom_iris]
platform_remove+0x20/0x30
device_remove+0x4c/0x80
<snip>
---[ end trace 0000000000000000 ]---
genpd genpd:0:aa00000.video-codec: Runtime PM usage count underflow!
------------[ cut here ]------------
gcc_video_axi0_clk already disabled
WARNING: drivers/clk/clk.c:1206 at clk_core_disable+0xa4/0xac, CPU#4: sh/542
<snip>
pc : clk_core_disable+0xa4/0xac
lr : clk_core_disable+0xa4/0xac
<snip>
Call trace:
clk_core_disable+0xa4/0xac (P)
clk_disable+0x30/0x4c
iris_disable_unprepare_clock+0x20/0x48 [qcom_iris]
iris_vpu33_power_off_controller+0x17c/0x428 [qcom_iris]
iris_vpu_power_off+0x48/0x84 [qcom_iris]
iris_core_deinit+0x44/0xc8 [qcom_iris]
iris_remove+0x20/0x48 [qcom_iris]
platform_remove+0x20/0x30
device_remove+0x4c/0x80
<snip>
------------[ cut here ]------------
gcc_video_axi0_clk already unprepared
WARNING: drivers/clk/clk.c:1065 at clk_core_unprepare+0xf0/0x110, CPU#4: sh/542
<snip>
pc : clk_core_unprepare+0xf0/0x110
lr : clk_core_unprepare+0xf0/0x110
<snip>
Call trace:
clk_core_unprepare+0xf0/0x110 (P)
clk_unprepare+0x2c/0x44
iris_disable_unprepare_clock+0x28/0x48 [qcom_iris]
iris_vpu33_power_off_controller+0x17c/0x428 [qcom_iris]
iris_vpu_power_off+0x48/0x84 [qcom_iris]
iris_core_deinit+0x44/0xc8 [qcom_iris]
iris_remove+0x20/0x48 [qcom_iris]
platform_remove+0x20/0x30
device_remove+0x4c/0x80
<snip>
---[ end trace 0000000000000000 ]---
Skip deinit if initialization never succeeded. |
| In the Linux kernel, the following vulnerability has been resolved:
Squashfs: reject negative file sizes in squashfs_read_inode()
Syskaller reports a "WARNING in ovl_copy_up_file" in overlayfs.
This warning is ultimately caused because the underlying Squashfs file
system returns a file with a negative file size.
This commit checks for a negative file size and returns EINVAL.
[phillip@squashfs.org.uk: only need to check 64 bit quantity] |
| In the Linux kernel, the following vulnerability has been resolved:
media: mc: Clear minor number before put device
The device minor should not be cleared after the device is released. |
| In the Linux kernel, the following vulnerability has been resolved:
mount: handle NULL values in mnt_ns_release()
When calling in listmount() mnt_ns_release() may be passed a NULL
pointer. Handle that case gracefully. |
| 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:
Revert "ipmi: fix msg stack when IPMI is disconnected"
This reverts commit c608966f3f9c2dca596967501d00753282b395fc.
This patch has a subtle bug that can cause the IPMI driver to go into an
infinite loop if the BMC misbehaves in a certain way. Apparently
certain BMCs do misbehave this way because several reports have come in
recently about this. |
| 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:
f2fs: invalidate dentry cache on failed whiteout creation
F2FS can mount filesystems with corrupted directory depth values that
get runtime-clamped to MAX_DIR_HASH_DEPTH. When RENAME_WHITEOUT
operations are performed on such directories, f2fs_rename performs
directory modifications (updating target entry and deleting source
entry) before attempting to add the whiteout entry via f2fs_add_link.
If f2fs_add_link fails due to the corrupted directory structure, the
function returns an error to VFS, but the partial directory
modifications have already been committed to disk. VFS assumes the
entire rename operation failed and does not update the dentry cache,
leaving stale mappings.
In the error path, VFS does not call d_move() to update the dentry
cache. This results in new_dentry still pointing to the old inode
(new_inode) which has already had its i_nlink decremented to zero.
The stale cache causes subsequent operations to incorrectly reference
the freed inode.
This causes subsequent operations to use cached dentry information that
no longer matches the on-disk state. When a second rename targets the
same entry, VFS attempts to decrement i_nlink on the stale inode, which
may already have i_nlink=0, triggering a WARNING in drop_nlink().
Example sequence:
1. First rename (RENAME_WHITEOUT): file2 → file1
- f2fs updates file1 entry on disk (points to inode 8)
- f2fs deletes file2 entry on disk
- f2fs_add_link(whiteout) fails (corrupted directory)
- Returns error to VFS
- VFS does not call d_move() due to error
- VFS cache still has: file1 → inode 7 (stale!)
- inode 7 has i_nlink=0 (already decremented)
2. Second rename: file3 → file1
- VFS uses stale cache: file1 → inode 7
- Tries to drop_nlink on inode 7 (i_nlink already 0)
- WARNING in drop_nlink()
Fix this by explicitly invalidating old_dentry and new_dentry when
f2fs_add_link fails during whiteout creation. This forces VFS to
refresh from disk on subsequent operations, ensuring cache consistency
even when the rename partially succeeds.
Reproducer:
1. Mount F2FS image with corrupted i_current_depth
2. renameat2(file2, file1, RENAME_WHITEOUT)
3. renameat2(file3, file1, 0)
4. System triggers WARNING in drop_nlink() |
| In the Linux kernel, the following vulnerability has been resolved:
pwm: berlin: Fix wrong register in suspend/resume
The 'enable' register should be BERLIN_PWM_EN rather than
BERLIN_PWM_ENABLE, otherwise, the driver accesses wrong address, there
will be cpu exception then kernel panic during suspend/resume. |
| In the Linux kernel, the following vulnerability has been resolved:
net: usb: lan78xx: Fix lost EEPROM read timeout error(-ETIMEDOUT) in lan78xx_read_raw_eeprom
Syzbot reported read of uninitialized variable BUG with following call stack.
lan78xx 8-1:1.0 (unnamed net_device) (uninitialized): EEPROM read operation timeout
=====================================================
BUG: KMSAN: uninit-value in lan78xx_read_eeprom drivers/net/usb/lan78xx.c:1095 [inline]
BUG: KMSAN: uninit-value in lan78xx_init_mac_address drivers/net/usb/lan78xx.c:1937 [inline]
BUG: KMSAN: uninit-value in lan78xx_reset+0x999/0x2cd0 drivers/net/usb/lan78xx.c:3241
lan78xx_read_eeprom drivers/net/usb/lan78xx.c:1095 [inline]
lan78xx_init_mac_address drivers/net/usb/lan78xx.c:1937 [inline]
lan78xx_reset+0x999/0x2cd0 drivers/net/usb/lan78xx.c:3241
lan78xx_bind+0x711/0x1690 drivers/net/usb/lan78xx.c:3766
lan78xx_probe+0x225c/0x3310 drivers/net/usb/lan78xx.c:4707
Local variable sig.i.i created at:
lan78xx_read_eeprom drivers/net/usb/lan78xx.c:1092 [inline]
lan78xx_init_mac_address drivers/net/usb/lan78xx.c:1937 [inline]
lan78xx_reset+0x77e/0x2cd0 drivers/net/usb/lan78xx.c:3241
lan78xx_bind+0x711/0x1690 drivers/net/usb/lan78xx.c:3766
The function lan78xx_read_raw_eeprom failed to properly propagate EEPROM
read timeout errors (-ETIMEDOUT). In the fallthrough path, it first
attempted to restore the pin configuration for LED outputs and then
returned only the status of that restore operation, discarding the
original timeout error.
As a result, callers could mistakenly treat the data buffer as valid
even though the EEPROM read had actually timed out with no data or partial
data.
To fix this, handle errors in restoring the LED pin configuration separately.
If the restore succeeds, return any prior EEPROM timeout error correctly
to the caller. |
| In the Linux kernel, the following vulnerability has been resolved:
ice: ice_adapter: release xa entry on adapter allocation failure
When ice_adapter_new() fails, the reserved XArray entry created by
xa_insert() is not released. This causes subsequent insertions at
the same index to return -EBUSY, potentially leading to
NULL pointer dereferences.
Reorder the operations as suggested by Przemek Kitszel:
1. Check if adapter already exists (xa_load)
2. Reserve the XArray slot (xa_reserve)
3. Allocate the adapter (ice_adapter_new)
4. Store the adapter (xa_store) |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Fix debug checking for np-guests using huge mappings
When running with transparent huge pages and CONFIG_NVHE_EL2_DEBUG then
the debug checking in assert_host_shared_guest() fails on the launch of an
np-guest. This WARN_ON() causes a panic and generates the stack below.
In __pkvm_host_relax_perms_guest() the debug checking assumes the mapping
is a single page but it may be a block map. Update the checking so that
the size is not checked and just assumes the correct size.
While we're here make the same fix in __pkvm_host_mkyoung_guest().
Info: # lkvm run -k /share/arch/arm64/boot/Image -m 704 -c 8 --name guest-128
Info: Removed ghost socket file "/.lkvm//guest-128.sock".
[ 1406.521757] kvm [141]: nVHE hyp BUG at: arch/arm64/kvm/hyp/nvhe/mem_protect.c:1088!
[ 1406.521804] kvm [141]: nVHE call trace:
[ 1406.521828] kvm [141]: [<ffff8000811676b4>] __kvm_nvhe_hyp_panic+0xb4/0xe8
[ 1406.521946] kvm [141]: [<ffff80008116d12c>] __kvm_nvhe_assert_host_shared_guest+0xb0/0x10c
[ 1406.522049] kvm [141]: [<ffff80008116f068>] __kvm_nvhe___pkvm_host_relax_perms_guest+0x48/0x104
[ 1406.522157] kvm [141]: [<ffff800081169df8>] __kvm_nvhe_handle___pkvm_host_relax_perms_guest+0x64/0x7c
[ 1406.522250] kvm [141]: [<ffff800081169f0c>] __kvm_nvhe_handle_trap+0x8c/0x1a8
[ 1406.522333] kvm [141]: [<ffff8000811680fc>] __kvm_nvhe___skip_pauth_save+0x4/0x4
[ 1406.522454] kvm [141]: ---[ end nVHE call trace ]---
[ 1406.522477] kvm [141]: Hyp Offset: 0xfffece8013600000
[ 1406.522554] Kernel panic - not syncing: HYP panic:
[ 1406.522554] PS:834003c9 PC:0000b1806db6d170 ESR:00000000f2000800
[ 1406.522554] FAR:ffff8000804be420 HPFAR:0000000000804be0 PAR:0000000000000000
[ 1406.522554] VCPU:0000000000000000
[ 1406.523337] CPU: 3 UID: 0 PID: 141 Comm: kvm-vcpu-0 Not tainted 6.16.0-rc7 #97 PREEMPT
[ 1406.523485] Hardware name: FVP Base RevC (DT)
[ 1406.523566] Call trace:
[ 1406.523629] show_stack+0x18/0x24 (C)
[ 1406.523753] dump_stack_lvl+0xd4/0x108
[ 1406.523899] dump_stack+0x18/0x24
[ 1406.524040] panic+0x3d8/0x448
[ 1406.524184] nvhe_hyp_panic_handler+0x10c/0x23c
[ 1406.524325] kvm_handle_guest_abort+0x68c/0x109c
[ 1406.524500] handle_exit+0x60/0x17c
[ 1406.524630] kvm_arch_vcpu_ioctl_run+0x2e0/0x8c0
[ 1406.524794] kvm_vcpu_ioctl+0x1a8/0x9cc
[ 1406.524919] __arm64_sys_ioctl+0xac/0x104
[ 1406.525067] invoke_syscall+0x48/0x10c
[ 1406.525189] el0_svc_common.constprop.0+0x40/0xe0
[ 1406.525322] do_el0_svc+0x1c/0x28
[ 1406.525441] el0_svc+0x38/0x120
[ 1406.525588] el0t_64_sync_handler+0x10c/0x138
[ 1406.525750] el0t_64_sync+0x1ac/0x1b0
[ 1406.525876] SMP: stopping secondary CPUs
[ 1406.525965] Kernel Offset: disabled
[ 1406.526032] CPU features: 0x0000,00000080,8e134ca1,9446773f
[ 1406.526130] Memory Limit: none
[ 1406.959099] ---[ end Kernel panic - not syncing: HYP panic:
[ 1406.959099] PS:834003c9 PC:0000b1806db6d170 ESR:00000000f2000800
[ 1406.959099] FAR:ffff8000804be420 HPFAR:0000000000804be0 PAR:0000000000000000
[ 1406.959099] VCPU:0000000000000000 ] |
| 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. |
| 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:
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. |
