Search Results (26160 CVEs found)

CVE Vendors Products Updated CVSS v3.1
CVE-2025-40220 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
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.
CVE-2025-40218 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: mm/damon/vaddr: do not repeat pte_offset_map_lock() until success DAMON's virtual address space operation set implementation (vaddr) calls pte_offset_map_lock() inside the page table walk callback function. This is for reading and writing page table accessed bits. If pte_offset_map_lock() fails, it retries by returning the page table walk callback function with ACTION_AGAIN. pte_offset_map_lock() can continuously fail if the target is a pmd migration entry, though. Hence it could cause an infinite page table walk if the migration cannot be done until the page table walk is finished. This indeed caused a soft lockup when CPU hotplugging and DAMON were running in parallel. Avoid the infinite loop by simply not retrying the page table walk. DAMON is promising only a best-effort accuracy, so missing access to such pages is no problem.
CVE-2025-40230 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: mm: prevent poison consumption when splitting THP When performing memory error injection on a THP (Transparent Huge Page) mapped to userspace on an x86 server, the kernel panics with the following trace. The expected behavior is to terminate the affected process instead of panicking the kernel, as the x86 Machine Check code can recover from an in-userspace #MC. mce: [Hardware Error]: CPU 0: Machine Check Exception: f Bank 3: bd80000000070134 mce: [Hardware Error]: RIP 10:<ffffffff8372f8bc> {memchr_inv+0x4c/0xf0} mce: [Hardware Error]: TSC afff7bbff88a ADDR 1d301b000 MISC 80 PPIN 1e741e77539027db mce: [Hardware Error]: PROCESSOR 0:d06d0 TIME 1758093249 SOCKET 0 APIC 0 microcode 80000320 mce: [Hardware Error]: Run the above through 'mcelog --ascii' mce: [Hardware Error]: Machine check: Data load in unrecoverable area of kernel Kernel panic - not syncing: Fatal local machine check The root cause of this panic is that handling a memory failure triggered by an in-userspace #MC necessitates splitting the THP. The splitting process employs a mechanism, implemented in try_to_map_unused_to_zeropage(), which reads the pages in the THP to identify zero-filled pages. However, reading the pages in the THP results in a second in-kernel #MC, occurring before the initial memory_failure() completes, ultimately leading to a kernel panic. See the kernel panic call trace on the two #MCs. First Machine Check occurs // [1] memory_failure() // [2] try_to_split_thp_page() split_huge_page() split_huge_page_to_list_to_order() __folio_split() // [3] remap_page() remove_migration_ptes() remove_migration_pte() try_to_map_unused_to_zeropage() // [4] memchr_inv() // [5] Second Machine Check occurs // [6] Kernel panic [1] Triggered by accessing a hardware-poisoned THP in userspace, which is typically recoverable by terminating the affected process. [2] Call folio_set_has_hwpoisoned() before try_to_split_thp_page(). [3] Pass the RMP_USE_SHARED_ZEROPAGE remap flag to remap_page(). [4] Try to map the unused THP to zeropage. [5] Re-access pages in the hw-poisoned THP in the kernel. [6] Triggered in-kernel, leading to a panic kernel. In Step[2], memory_failure() sets the poisoned flag on the page in the THP by TestSetPageHWPoison() before calling try_to_split_thp_page(). As suggested by David Hildenbrand, fix this panic by not accessing to the poisoned page in the THP during zeropage identification, while continuing to scan unaffected pages in the THP for possible zeropage mapping. This prevents a second in-kernel #MC that would cause kernel panic in Step[4]. Thanks to Andrew Zaborowski for his initial work on fixing this issue.
CVE-2025-40232 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: rv: Fully convert enabled_monitors to use list_head as iterator The callbacks in enabled_monitors_seq_ops are inconsistent. Some treat the iterator as struct rv_monitor *, while others treat the iterator as struct list_head *. This causes a wrong type cast and crashes the system as reported by Nathan. Convert everything to use struct list_head * as iterator. This also makes enabled_monitors consistent with available_monitors.
CVE-2025-40236 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: virtio-net: zero unused hash fields When GSO tunnel is negotiated virtio_net_hdr_tnl_from_skb() tries to initialize the tunnel metadata but forget to zero unused rxhash fields. This may leak information to another side. Fixing this by zeroing the unused hash fields.
CVE-2025-40207 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
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().
CVE-2025-40208 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
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.
CVE-2025-40200 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
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]
CVE-2025-40197 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
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.
CVE-2025-40195 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
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.
CVE-2025-40193 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
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()")
CVE-2025-40192 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
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.
CVE-2025-40191 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
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.
CVE-2025-40188 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
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.
CVE-2025-40189 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
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.
CVE-2025-20093 2 Intel, Linux 2 Ethernet 800 Series Software, Linux Kernel 2026-04-15 8.2 High
Improper check for unusual or exceptional conditions in the Linux kernel-mode driver for some Intel(R) 800 Series Ethernet before version 1.17.2 may allow an authenticated user to potentially enable escalation of privilege via local access.
CVE-2025-40185 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
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)
CVE-2025-40184 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
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 ]
CVE-2025-40194 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
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.
CVE-2025-40181 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
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---