CVE-2026-64417

CVE CVE-2026-64417EUVD EUVD-2026-48961Published 2026-07-25T08:50:56.000Z

What the advisory describes

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.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

Linux — Linux bbf535fd6f06b94b9d07ed6f09397a936d4a58d8 <e30453c61e185e914fde83c650e268067b140218; patch: 6.18.39; bbf535fd6f06b94b9d07ed6f09397a936d4a58d8 <09d2407985b8ce3e831f9d4310fe7ac06a6b3ae9; bbf535fd6f06b94b9d07ed6f09397a936d4a58d8 <ebb45c2648b1f60715fd283700f651e05e431231; 6.0; patch: 6.6.145; patch: 6.12.96; patch: 6.1.178; patch: 0; patch: 7.1.4; bbf535fd6f06b94b9d07ed6f09397a936d4a58d8 <36f8534f461222291a74156ab91f3ba9f09b6f93; patch: 7.2-rc3; bbf535fd6f06b94b9d07ed6f09397a936d4a58d8 <b9beed2322f3538b0d2d53307062da4102b8d8d8; bbf535fd6f06b94b9d07ed6f09397a936d4a58d8 <006467ab932698612398f853344a7405164541f4

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

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Linux — Linux

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