CVE-2024-40915: Linux kernel · riscv: rewrite __kernel_map_pages() to fix sleeping in invalid context
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 5.15.0-1072.78~20.04.1 : update Linux kernel when convenient.
Data as of 12 Nov 2026, 19:04 UTC
- Patch
- Available – fixed in 5.15.0-1072.78~20.04.1, 5.15.0-1078.87~20.04.1, 5.15.0-1071.79~20.04.1 +48
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 12 Jul 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 12 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-6999-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7004-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7005-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7008-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7005-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6999-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7029-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7100-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7100-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7123-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7144-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7194-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-ibmpkg:deb/ubuntu/linux-ibm?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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.
References
- ubuntu.com/security/CVE-2024-40915 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-40915 (opens in a new tab)
- git.kernel.org/linus/fb1cf0878328fe75d47f0aed0a65b30126fcefc4 (opens in a new tab)
- git.kernel.org/stable/c/919f8626099d9909b9a9620b05e8c8ab06581876 (opens in a new tab)
- git.kernel.org/stable/c/8661a7af04991201640863ad1a0983173f84b5eb (opens in a new tab)
- git.kernel.org/stable/c/d5257ceb19d92069195254866421f425aea42915 (opens in a new tab)
- git.kernel.org/stable/c/fb1cf0878328fe75d47f0aed0a65b30126fcefc4 (opens in a new tab)
- ubuntu.com/security/notices/USN-6999-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7004-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7005-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7008-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7005-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6999-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7029-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7100-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7100-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7123-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7144-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7194-1 (opens in a new tab)