CVE-2026-43015

Published May 1, 2026

Last updated 17 days ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: net: macb: fix clk handling on PCI glue driver removal platform_device_unregister() may still want to use the registered clks during runtime resume callback. Note that there is a commit d82d5303c4c5 ("net: macb: fix use after free on rmmod") that addressed the similar problem of clk vs platform device unregistration but just moved the bug to another place. Save the pointers to clks into local variables for reuse after platform device is unregistered. BUG: KASAN: use-after-free in clk_prepare+0x5a/0x60 Read of size 8 at addr ffff888104f85e00 by task modprobe/597 CPU: 2 PID: 597 Comm: modprobe Not tainted 6.1.164+ #114 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x8d/0xba print_report+0x17f/0x496 kasan_report+0xd9/0x180 clk_prepare+0x5a/0x60 macb_runtime_resume+0x13d/0x410 [macb] pm_generic_runtime_resume+0x97/0xd0 __rpm_callback+0xc8/0x4d0 rpm_callback+0xf6/0x230 rpm_resume+0xeeb/0x1a70 __pm_runtime_resume+0xb4/0x170 bus_remove_device+0x2e3/0x4b0 device_del+0x5b3/0xdc0 platform_device_del+0x4e/0x280 platform_device_unregister+0x11/0x50 pci_device_remove+0xae/0x210 device_remove+0xcb/0x180 device_release_driver_internal+0x529/0x770 driver_detach+0xd4/0x1a0 bus_remove_driver+0x135/0x260 driver_unregister+0x72/0xb0 pci_unregister_driver+0x26/0x220 __do_sys_delete_module+0x32e/0x550 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 </TASK> Allocated by task 519: kasan_save_stack+0x2c/0x50 kasan_set_track+0x21/0x30 __kasan_kmalloc+0x8e/0x90 __clk_register+0x458/0x2890 clk_hw_register+0x1a/0x60 __clk_hw_register_fixed_rate+0x255/0x410 clk_register_fixed_rate+0x3c/0xa0 macb_probe+0x1d8/0x42e [macb_pci] local_pci_probe+0xd7/0x190 pci_device_probe+0x252/0x600 really_probe+0x255/0x7f0 __driver_probe_device+0x1ee/0x330 driver_probe_device+0x4c/0x1f0 __driver_attach+0x1df/0x4e0 bus_for_each_dev+0x15d/0x1f0 bus_add_driver+0x486/0x5e0 driver_register+0x23a/0x3d0 do_one_initcall+0xfd/0x4d0 do_init_module+0x18b/0x5a0 load_module+0x5663/0x7950 __do_sys_finit_module+0x101/0x180 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 Freed by task 597: kasan_save_stack+0x2c/0x50 kasan_set_track+0x21/0x30 kasan_save_free_info+0x2a/0x50 __kasan_slab_free+0x106/0x180 __kmem_cache_free+0xbc/0x320 clk_unregister+0x6de/0x8d0 macb_remove+0x73/0xc0 [macb_pci] pci_device_remove+0xae/0x210 device_remove+0xcb/0x180 device_release_driver_internal+0x529/0x770 driver_detach+0xd4/0x1a0 bus_remove_driver+0x135/0x260 driver_unregister+0x72/0xb0 pci_unregister_driver+0x26/0x220 __do_sys_delete_module+0x32e/0x550 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x6e/0xd8
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Analyzed
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
7.8
Impact score
5.9
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Severity
HIGH

Weaknesses

nvd@nist.gov
CWE-416

Social media

Hype score
Not currently trending

Configurations

  1. In the Linux kernel, the following vulnerability has been resolved: scsi: storvsc: Fix scheduling while atomic on PREEMPT_RT This resolves the follow splat and lock-up when running with PREEMPT_RT enabled on Hyper-V: [ 415.140818] BUG: scheduling while atomic: stress-ng-iomix/1048/0x00000002 [ 415.140822] INFO: lockdep is turned off. [ 415.140823] Modules linked in: intel_rapl_msr intel_rapl_common intel_uncore_frequency_common intel_pmc_core pmt_telemetry pmt_discovery pmt_class intel_pmc_ssram_telemetry intel_vsec ghash_clmulni_intel aesni_intel rapl binfmt_misc nls_ascii nls_cp437 vfat fat snd_pcm hyperv_drm snd_timer drm_client_lib drm_shmem_helper snd sg soundcore drm_kms_helper pcspkr hv_balloon hv_utils evdev joydev drm configfs efi_pstore nfnetlink vsock_loopback vmw_vsock_virtio_transport_common hv_sock vmw_vsock_vmci_transport vsock vmw_vmci efivarfs autofs4 ext4 crc16 mbcache jbd2 sr_mod sd_mod cdrom hv_storvsc serio_raw hid_generic scsi_transport_fc hid_hyperv scsi_mod hid hv_netvsc hyperv_keyboard scsi_common [ 415.140846] Preemption disabled at: [ 415.140847] [<ffffffffc0656171>] storvsc_queuecommand+0x2e1/0xbe0 [hv_storvsc] [ 415.140854] CPU: 8 UID: 0 PID: 1048 Comm: stress-ng-iomix Not tainted 6.19.0-rc7 #30 PREEMPT_{RT,(full)} [ 415.140856] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 09/04/2024 [ 415.140857] Call Trace: [ 415.140861] <TASK> [ 415.140861] ? storvsc_queuecommand+0x2e1/0xbe0 [hv_storvsc] [ 415.140863] dump_stack_lvl+0x91/0xb0 [ 415.140870] __schedule_bug+0x9c/0xc0 [ 415.140875] __schedule+0xdf6/0x1300 [ 415.140877] ? rtlock_slowlock_locked+0x56c/0x1980 [ 415.140879] ? rcu_is_watching+0x12/0x60 [ 415.140883] schedule_rtlock+0x21/0x40 [ 415.140885] rtlock_slowlock_locked+0x502/0x1980 [ 415.140891] rt_spin_lock+0x89/0x1e0 [ 415.140893] hv_ringbuffer_write+0x87/0x2a0 [ 415.140899] vmbus_sendpacket_mpb_desc+0xb6/0xe0 [ 415.140900] ? rcu_is_watching+0x12/0x60 [ 415.140902] storvsc_queuecommand+0x669/0xbe0 [hv_storvsc] [ 415.140904] ? HARDIRQ_verbose+0x10/0x10 [ 415.140908] ? __rq_qos_issue+0x28/0x40 [ 415.140911] scsi_queue_rq+0x760/0xd80 [scsi_mod] [ 415.140926] __blk_mq_issue_directly+0x4a/0xc0 [ 415.140928] blk_mq_issue_direct+0x87/0x2b0 [ 415.140931] blk_mq_dispatch_queue_requests+0x120/0x440 [ 415.140933] blk_mq_flush_plug_list+0x7a/0x1a0 [ 415.140935] __blk_flush_plug+0xf4/0x150 [ 415.140940] __submit_bio+0x2b2/0x5c0 [ 415.140944] ? submit_bio_noacct_nocheck+0x272/0x360 [ 415.140946] submit_bio_noacct_nocheck+0x272/0x360 [ 415.140951] ext4_read_bh_lock+0x3e/0x60 [ext4] [ 415.140995] ext4_block_write_begin+0x396/0x650 [ext4] [ 415.141018] ? __pfx_ext4_da_get_block_prep+0x10/0x10 [ext4] [ 415.141038] ext4_da_write_begin+0x1c4/0x350 [ext4] [ 415.141060] generic_perform_write+0x14e/0x2c0 [ 415.141065] ext4_buffered_write_iter+0x6b/0x120 [ext4] [ 415.141083] vfs_write+0x2ca/0x570 [ 415.141087] ksys_write+0x76/0xf0 [ 415.141089] do_syscall_64+0x99/0x1490 [ 415.141093] ? rcu_is_watching+0x12/0x60 [ 415.141095] ? finish_task_switch.isra.0+0xdf/0x3d0 [ 415.141097] ? rcu_is_watching+0x12/0x60 [ 415.141098] ? lock_release+0x1f0/0x2a0 [ 415.141100] ? rcu_is_watching+0x12/0x60 [ 415.141101] ? finish_task_switch.isra.0+0xe4/0x3d0 [ 415.141103] ? rcu_is_watching+0x12/0x60 [ 415.141104] ? __schedule+0xb34/0x1300 [ 415.141106] ? hrtimer_try_to_cancel+0x1d/0x170 [ 415.141109] ? do_nanosleep+0x8b/0x160 [ 415.141111] ? hrtimer_nanosleep+0x89/0x100 [ 415.141114] ? __pfx_hrtimer_wakeup+0x10/0x10 [ 415.141116] ? xfd_validate_state+0x26/0x90 [ 415.141118] ? rcu_is_watching+0x12/0x60 [ 415.141120] ? do_syscall_64+0x1e0/0x1490 [ 415.141121] ? do_syscall_64+0x1e0/0x1490 [ 415.141123] ? rcu_is_watching+0x12/0x60 [ 415.141124] ? do_syscall_64+0x1e0/0x1490 [ 415.141125] ? do_syscall_64+0x1e0/0x1490 [ 415.141127] ? irqentry_exit+0x140/0 ---truncated---CVE-2026-43475
  2. In the Linux kernel, the following vulnerability has been resolved: unshare: fix unshare_fs() handling There's an unpleasant corner case in unshare(2), when we have a CLONE_NEWNS in flags and current->fs hadn't been shared at all; in that case copy_mnt_ns() gets passed current->fs instead of a private copy, which causes interesting warts in proof of correctness] > I guess if private means fs->users == 1, the condition could still be true. Unfortunately, it's worse than just a convoluted proof of correctness. Consider the case when we have CLONE_NEWCGROUP in addition to CLONE_NEWNS (and current->fs->users == 1). We pass current->fs to copy_mnt_ns(), all right. Suppose it succeeds and flips current->fs->{pwd,root} to corresponding locations in the new namespace. Now we proceed to copy_cgroup_ns(), which fails (e.g. with -ENOMEM). We call put_mnt_ns() on the namespace created by copy_mnt_ns(), it's destroyed and its mount tree is dissolved, but... current->fs->root and current->fs->pwd are both left pointing to now detached mounts. They are pinning those, so it's not a UAF, but it leaves the calling process with unshare(2) failing with -ENOMEM _and_ leaving it with pwd and root on detached isolated mounts. The last part is clearly a bug. There is other fun related to that mess (races with pivot_root(), including the one between pivot_root() and fork(), of all things), but this one is easy to isolate and fix - treat CLONE_NEWNS as "allocate a new fs_struct even if it hadn't been shared in the first place". Sure, we could go for something like "if both CLONE_NEWNS *and* one of the things that might end up failing after copy_mnt_ns() call in create_new_namespaces() are set, force allocation of new fs_struct", but let's keep it simple - the cost of copy_fs_struct() is trivial. Another benefit is that copy_mnt_ns() with CLONE_NEWNS *always* gets a freshly allocated fs_struct, yet to be attached to anything. That seriously simplifies the analysis... FWIW, that bug had been there since the introduction of unshare(2) ;-/CVE-2026-43472