CVE-2024-40915: linux kernel — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: riscv: rewrite __kernel_map_pages() to fix sleeping in invalid context __kernel_map_pages() is a debug function which clears the valid bit in page table entry for deallocated pages to detect illegal memory accesses to freed pages. This function set/clear the valid bit using __set_memory(). __set_memory() acquires init_mm's semaphore, and this operation may sleep. This is problematic, because __kernel_map_pages() can be called in atomic context, and thus is illegal to sleep. An example warning that this causes: BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1578 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2, name: kthreadd preempt_count: 2, expected: 0 CPU: 0 PID: 2 Comm: kthreadd Not tainted 6.9.0-g1d4c6d784ef6 #37 Hardware name: riscv-virtio,qemu (DT) Call Trace: [<ffffffff800060dc>] dump_backtrace+0x1c/0x24 [<ffffffff8091ef6e>] show_stack+0x2c/0x38 [<ffffffff8092baf8>] dump_stack_lvl+0x5a/0x72 [<ffffffff8092bb24>] dump_stack+0x14/0x1c [<ffffffff8003b7ac>] __might_resched+0x104/0x10e [<ffffffff8003b7f4>] __might_sleep+0x3e/0x62 [<ffffffff8093276a>] down_write+0x20/0x72 [<ffffffff8000cf00>] __set_memory+0x82/0x2fa [<ffffffff8000d324>] __kernel_map_pages+0x5a/0xd4 [<ffffffff80196cca>] __alloc_pages_bulk+0x3b2/0x43a [<ffffffff8018ee82>] __vmalloc_node_range+0x196/0x6ba [<ffffffff80011904>] copy_process+0x72c/0x17ec [<ffffffff80012ab4>] kernel_clone+0x60/0x2fe [<ffffffff80012f62>] kernel_thread+0x82/0xa0 [<ffffffff8003552c>] kthreadd+0x14a/0x1be [<ffffffff809357de>] ret_from_fork+0xe/0x1c Rewrite this function with apply_to_existing_page_range(). It is fine to not have any locking, because __kernel_map_pages() works with pages being allocated/deallocated and those pages are not changed by anyone else in the meantime.

Is your site exposed to CVE-2024-40915?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

5.5

MEDIUM

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

Weakness Type (CWE)

CWE-667 CWE-667

Affected Products

Vendor	Product	Versions
linux	linux_kernel	5.7 — 6.1.95
linux	linux_kernel	6.2 — 6.6.35
linux	linux_kernel	6.7 — 6.9.6

References

Advisories & Patches

https://git.kernel.org/stable/c/8661a7af04991201640863ad1a0983173f84b5eb https://git.kernel.org/stable/c/919f8626099d9909b9a9620b05e8c8ab06581876 https://git.kernel.org/stable/c/d5257ceb19d92069195254866421f425aea42915 https://git.kernel.org/stable/c/fb1cf0878328fe75d47f0aed0a65b30126fcefc4 https://git.kernel.org/stable/c/8661a7af04991201640863ad1a0983173f84b5eb https://git.kernel.org/stable/c/919f8626099d9909b9a9620b05e8c8ab06581876 https://git.kernel.org/stable/c/d5257ceb19d92069195254866421f425aea42915 https://git.kernel.org/stable/c/fb1cf0878328fe75d47f0aed0a65b30126fcefc4

Other References

https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html

Frequently Asked Questions

What is CVE-2024-40915? +

In the Linux kernel, the following vulnerability has been resolved: riscv: rewrite __kernel_map_pages() to fix sleeping in invalid context __kernel_map_pages() is a debug function which clears the valid bit in page table entry for deallocated pages to detect illegal memory accesses to freed pages. This function set/clear the valid bit using __set_memory(). __set_memory() acquires init_mm's semaphore, and this operation may sleep. This is problematic, because __kernel_map_pages() can be called in atomic context, and thus is illegal to sleep. An example warning that this causes: BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1578 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2, name: kthreadd preempt_count: 2, expected: 0 CPU: 0 PID: 2 Comm: kthreadd Not tainted 6.9.0-g1d4c6d784ef6 #37 Hardware name: riscv-virtio,qemu (DT) Call Trace: [<ffffffff800060dc>] dump_backtrace+0x1c/0x24 [<ffffffff8091ef6e>] show_stack+0x2c/0x38 [<ffffffff8092baf8>] dump_stack_lvl+0x5a/0x72 [<ffffffff8092bb24>] dump_stack+0x14/0x1c [<ffffffff8003b7ac>] __might_resched+0x104/0x10e [<ffffffff8003b7f4>] __might_sleep+0x3e/0x62 [<ffffffff8093276a>] down_write+0x20/0x72 [<ffffffff8000cf00>] __set_memory+0x82/0x2fa [<ffffffff8000d324>] __kernel_map_pages+0x5a/0xd4 [<ffffffff80196cca>] __alloc_pages_bulk+0x3b2/0x43a [<ffffffff8018ee82>] __vmalloc_node_range+0x196/0x6ba [<ffffffff80011904>] copy_process+0x72c/0x17ec [<ffffffff80012ab4>] kernel_clone+0x60/0x2fe [<ffffffff80012f62>] kernel_thread+0x82/0xa0 [<ffffffff8003552c>] kthreadd+0x14a/0x1be [<ffffffff809357de>] ret_from_fork+0xe/0x1c Rewrite this function with apply_to_existing_page_range(). It is fine to not have any locking, because __kernel_map_pages() works with pages being allocated/deallocated and those pages are not changed by anyone else in the meantime. It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2024-40915? +

CVE-2024-40915 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2024-40915? +

CVE-2024-40915 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2024-40915? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2025-1221

A Zigbee Radio Co-Processor (RCP), which is using SiLabs EmberZNet Zigbee stack, was unable to send messages to the host …

CVE-2025-10151

Improper locking vulnerability in Softing Industrial Automation GmbH gateways allows infected memory and/or resource leak exposure.This issue affects smartLink HW-PN: …

CVE-2026-54906 9.8

concurrent-ruby is a modern concurrency tools for Ruby. Prior to 1.3.7, Concurrent::ReadWriteLock#release_write_lock does not verify that the calling thread acquired …

CVE-2026-43215 8.8

In the Linux kernel, the following vulnerability has been resolved: cifs: Fix locking usage for tcon fields We used to …

CVE-2026-31629 8.8

In the Linux kernel, the following vulnerability has been resolved: nfc: llcp: add missing return after LLCP_CLOSED checks In nfc_llcp_recv_hdlc() …

CVE-2026-62426 8.8

[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] To manage the …

CVE-2024-40915