mm/kmemleak: avoid scanning potential huge holes

Description

In the Linux kernel, the following vulnerability has been resolved: mm/kmemleak: avoid scanning potential huge holes When using devm_request_free_mem_region() and devm_memremap_pages() to add ZONE_DEVICE memory, if requested free mem region's end pfn were huge(e.g., 0x400000000), the node_end_pfn() will be also huge (see move_pfn_range_to_zone()). Thus it creates a huge hole between node_start_pfn() and node_end_pfn(). We found on some AMD APUs, amdkfd requested such a free mem region and created a huge hole. In such a case, following code snippet was just doing busy test_bit() looping on the huge hole. for (pfn = start_pfn; pfn < end_pfn; pfn++) { struct page *page = pfn_to_online_page(pfn); if (!page) continue; ... } So we got a soft lockup: watchdog: BUG: soft lockup - CPU#6 stuck for 26s! [bash:1221] CPU: 6 PID: 1221 Comm: bash Not tainted 5.15.0-custom #1 RIP: 0010:pfn_to_online_page+0x5/0xd0 Call Trace: ? kmemleak_scan+0x16a/0x440 kmemleak_write+0x306/0x3a0 ? common_file_perm+0x72/0x170 full_proxy_write+0x5c/0x90 vfs_write+0xb9/0x260 ksys_write+0x67/0xe0 __x64_sys_write+0x1a/0x20 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xae I did some tests with the patch. (1) amdgpu module unloaded before the patch: real 0m0.976s user 0m0.000s sys 0m0.968s after the patch: real 0m0.981s user 0m0.000s sys 0m0.973s (2) amdgpu module loaded before the patch: real 0m35.365s user 0m0.000s sys 0m35.354s after the patch: real 0m1.049s user 0m0.000s sys 0m1.042s

Scores

EPSS (exploitation in 30 days)

0.17% · top 94% of all CVEs (6 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.

Weakness

• CWE-noinfo Not enough information
• CWE-667 (opens in a new tab)All about CWE-667 and its CVEs

Affected products

• Linux · Linux

  • affected 4ef589dc9b10cdcae75a2b2b0e9b2c5e8a92c378 – < d3533ee20e9a0e2e8f60384da7450d43d1c63d1a
  • affected 4ef589dc9b10cdcae75a2b2b0e9b2c5e8a92c378 – < 352715593e81b917ce1b321e794549815b850134
  • affected 4ef589dc9b10cdcae75a2b2b0e9b2c5e8a92c378 – < a5389c80992f0001ee505838fe6a8b20897ce96e
  • affected 4ef589dc9b10cdcae75a2b2b0e9b2c5e8a92c378 – < cebb0aceb21ad91429617a40e3a17444fabf1529
  • affected 4ef589dc9b10cdcae75a2b2b0e9b2c5e8a92c378 – < c10a0f877fe007021d70f9cada240f42adc2b5db

• Linux · Linux

  • affected 4.14
  • unaffected < 4.14
  • unaffected 5.4.178 – ≤ 5.4.*
  • unaffected 5.10.99 – ≤ 5.10.*
  • unaffected 5.15.22 – ≤ 5.15.*
  • unaffected 5.16.8 – ≤ 5.16.*
  • unaffected 5.17 – ≤ *

References (5)

• https://git.kernel.org/stable/c/d3533ee20e9a0e2e8f60384da7450d43d1c63d1a (opens in a new tab)x_transferred
• https://git.kernel.org/stable/c/352715593e81b917ce1b321e794549815b850134 (opens in a new tab)x_transferred
• https://git.kernel.org/stable/c/a5389c80992f0001ee505838fe6a8b20897ce96e (opens in a new tab)x_transferred
• https://git.kernel.org/stable/c/cebb0aceb21ad91429617a40e3a17444fabf1529 (opens in a new tab)x_transferred
• https://git.kernel.org/stable/c/c10a0f877fe007021d70f9cada240f42adc2b5db (opens in a new tab)x_transferred

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2022-48731](https://trackcve.app/badge/CVE-2022-48731.svg)](https://trackcve.app/cve/CVE-2022-48731)

Record last updated 11 May 2026, 18:45 UTC.