Answer in brief
CVE-2026-64417 records a Medium severity (CVSS 5.5) vulnerability in mm: shrinker: fix NULL pointer dereference in debugfs. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:7.2:rc1:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:7.2:rc2:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=bbf535fd6f06b94b9d07ed6f09397a936d4a58d8 <ebb45c2648b1f60715fd283700f651e05e431231 || >=bbf535fd6f06b94b9d07ed6f09397a936d4a58d8 <09d2407985b8ce3e831f9d4310fe7ac06a6b3ae9 || >=bbf535fd6f06b94b9d07ed6f09397a936d4a58d8 <36f8534f461222291a74156ab91f3ba9f09b6f93 || >=bbf535fd6f06b94b9d07ed6f09397a936d4a58d8 <006467ab932698612398f853344a7405164541f4 || >=bbf535fd6f06b94b9d07ed6f09397a936d4a58d8 <b9beed2322f3538b0d2d53307062da4102b8d8d8 || >=bbf535fd6f06b94b9d07ed6f09397a936d4a58d8 <e30453c61e185e914fde83c650e268067b140218 | ebb45c2648b1f60715fd283700f651e05e431231, 09d2407985b8ce3e831f9d4310fe7ac06a6b3ae9, 36f8534f461222291a74156ab91f3ba9f09b6f93, 006467ab932698612398f853344a7405164541f4, b9beed2322f3538b0d2d53307062da4102b8d8d8, e30453c61e185e914fde83c650e268067b140218 |
| Linux/Linuxgeneric | 6.0 | Not reported |
Published upstream
Jul 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 4, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 11, 2026
In the Linux kernel, the following vulnerability has been resolved: mm: shrinker: fix NULL pointer dereference in debugfs shrinker_debugfs_add() creates both "count" and "scan" debugfs files unconditionally. That assumes every shrinker implements both count_objects() and scan_objects(), which is not guaranteed. For example, the xen-backend shrinker sets count_objects() but leaves scan_objects() NULL, so writing to its scan file calls through a NULL function pointer and panics the kernel: BUG: kernel NULL pointer dereference, address: 0000000000000000 RIP: 0010:0x0 Code: Unable to access opcode bytes at 0xffffffffffffffd6. Call Trace: <TASK> shrinker_debugfs_scan_write+0x12e/0x270 full_proxy_write+0x5f/0x90 vfs_write+0xde/0x420 ? filp_flush+0x75/0x90 ? filp_close+0x1d/0x30 ? do_dup2+0xb8/0x120 ksys_write+0x68/0xf0 ? filp_flush+0x75/0x90 do_syscall_64+0xb3/0x5b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e The count path has the same issue in principle if a shrinker omits count_objects(). To fix it, only create "count" and "scan" debugfs files when the corresponding callbacks are present.
Quoted source text, attributed separately from HOL analysis.