{"api_version":"1","generated_at":"2026-08-06T03:17:16+00:00","cve":"CVE-2026-64417","urls":{"html":"https://cve.report/CVE-2026-64417","api":"https://cve.report/api/cve/CVE-2026-64417.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-64417","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-64417"},"summary":{"title":"mm: shrinker: fix NULL pointer dereference in debugfs","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm: shrinker: fix NULL pointer dereference in debugfs\n\nshrinker_debugfs_add() creates both \"count\" and \"scan\" debugfs files\nunconditionally.\n\nThat assumes every shrinker implements both count_objects() and\nscan_objects(), which is not guaranteed.  For example, the xen-backend\nshrinker sets count_objects() but leaves scan_objects() NULL, so writing\nto its scan file calls through a NULL function pointer and panics the\nkernel:\n\nBUG: kernel NULL pointer dereference, address: 0000000000000000\nRIP: 0010:0x0\nCode: Unable to access opcode bytes at 0xffffffffffffffd6.\nCall Trace:\n <TASK>\n shrinker_debugfs_scan_write+0x12e/0x270\n full_proxy_write+0x5f/0x90\n vfs_write+0xde/0x420\n ? filp_flush+0x75/0x90\n ? filp_close+0x1d/0x30\n ? do_dup2+0xb8/0x120\n ksys_write+0x68/0xf0\n ? filp_flush+0x75/0x90\n do_syscall_64+0xb3/0x5b0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nThe count path has the same issue in principle if a shrinker omits\ncount_objects().\n\nTo fix it, only create \"count\" and \"scan\" debugfs files when the\ncorresponding callbacks are present.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-25 10:17:25","updated_at":"2026-07-25 10:17:25"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/b9beed2322f3538b0d2d53307062da4102b8d8d8","name":"https://git.kernel.org/stable/c/b9beed2322f3538b0d2d53307062da4102b8d8d8","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/ebb45c2648b1f60715fd283700f651e05e431231","name":"https://git.kernel.org/stable/c/ebb45c2648b1f60715fd283700f651e05e431231","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/09d2407985b8ce3e831f9d4310fe7ac06a6b3ae9","name":"https://git.kernel.org/stable/c/09d2407985b8ce3e831f9d4310fe7ac06a6b3ae9","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/006467ab932698612398f853344a7405164541f4","name":"https://git.kernel.org/stable/c/006467ab932698612398f853344a7405164541f4","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/36f8534f461222291a74156ab91f3ba9f09b6f93","name":"https://git.kernel.org/stable/c/36f8534f461222291a74156ab91f3ba9f09b6f93","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e30453c61e185e914fde83c650e268067b140218","name":"https://git.kernel.org/stable/c/e30453c61e185e914fde83c650e268067b140218","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-64417","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64417","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bbf535fd6f06b94b9d07ed6f09397a936d4a58d8 ebb45c2648b1f60715fd283700f651e05e431231 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bbf535fd6f06b94b9d07ed6f09397a936d4a58d8 09d2407985b8ce3e831f9d4310fe7ac06a6b3ae9 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bbf535fd6f06b94b9d07ed6f09397a936d4a58d8 36f8534f461222291a74156ab91f3ba9f09b6f93 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bbf535fd6f06b94b9d07ed6f09397a936d4a58d8 006467ab932698612398f853344a7405164541f4 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bbf535fd6f06b94b9d07ed6f09397a936d4a58d8 b9beed2322f3538b0d2d53307062da4102b8d8d8 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bbf535fd6f06b94b9d07ed6f09397a936d4a58d8 e30453c61e185e914fde83c650e268067b140218 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.0","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.0 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.178 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.145 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.96 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.39 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.4 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2-rc3 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"64417","cve":"CVE-2026-64417","epss":"0.001730000","percentile":"0.069630000","score_date":"2026-07-28","updated_at":"2026-07-29 00:05:33"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["mm/shrinker_debug.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"ebb45c2648b1f60715fd283700f651e05e431231","status":"affected","version":"bbf535fd6f06b94b9d07ed6f09397a936d4a58d8","versionType":"git"},{"lessThan":"09d2407985b8ce3e831f9d4310fe7ac06a6b3ae9","status":"affected","version":"bbf535fd6f06b94b9d07ed6f09397a936d4a58d8","versionType":"git"},{"lessThan":"36f8534f461222291a74156ab91f3ba9f09b6f93","status":"affected","version":"bbf535fd6f06b94b9d07ed6f09397a936d4a58d8","versionType":"git"},{"lessThan":"006467ab932698612398f853344a7405164541f4","status":"affected","version":"bbf535fd6f06b94b9d07ed6f09397a936d4a58d8","versionType":"git"},{"lessThan":"b9beed2322f3538b0d2d53307062da4102b8d8d8","status":"affected","version":"bbf535fd6f06b94b9d07ed6f09397a936d4a58d8","versionType":"git"},{"lessThan":"e30453c61e185e914fde83c650e268067b140218","status":"affected","version":"bbf535fd6f06b94b9d07ed6f09397a936d4a58d8","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["mm/shrinker_debug.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.0"},{"lessThan":"6.0","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.178","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.145","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.96","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.39","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2-rc3","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.178","versionStartIncluding":"6.0","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.145","versionStartIncluding":"6.0","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.96","versionStartIncluding":"6.0","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.39","versionStartIncluding":"6.0","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.4","versionStartIncluding":"6.0","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2-rc3","versionStartIncluding":"6.0","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm: shrinker: fix NULL pointer dereference in debugfs\n\nshrinker_debugfs_add() creates both \"count\" and \"scan\" debugfs files\nunconditionally.\n\nThat assumes every shrinker implements both count_objects() and\nscan_objects(), which is not guaranteed.  For example, the xen-backend\nshrinker sets count_objects() but leaves scan_objects() NULL, so writing\nto its scan file calls through a NULL function pointer and panics the\nkernel:\n\nBUG: kernel NULL pointer dereference, address: 0000000000000000\nRIP: 0010:0x0\nCode: Unable to access opcode bytes at 0xffffffffffffffd6.\nCall Trace:\n <TASK>\n shrinker_debugfs_scan_write+0x12e/0x270\n full_proxy_write+0x5f/0x90\n vfs_write+0xde/0x420\n ? filp_flush+0x75/0x90\n ? filp_close+0x1d/0x30\n ? do_dup2+0xb8/0x120\n ksys_write+0x68/0xf0\n ? filp_flush+0x75/0x90\n do_syscall_64+0xb3/0x5b0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nThe count path has the same issue in principle if a shrinker omits\ncount_objects().\n\nTo fix it, only create \"count\" and \"scan\" debugfs files when the\ncorresponding callbacks are present."}],"providerMetadata":{"dateUpdated":"2026-07-25T08:50:56.800Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/ebb45c2648b1f60715fd283700f651e05e431231"},{"url":"https://git.kernel.org/stable/c/09d2407985b8ce3e831f9d4310fe7ac06a6b3ae9"},{"url":"https://git.kernel.org/stable/c/36f8534f461222291a74156ab91f3ba9f09b6f93"},{"url":"https://git.kernel.org/stable/c/006467ab932698612398f853344a7405164541f4"},{"url":"https://git.kernel.org/stable/c/b9beed2322f3538b0d2d53307062da4102b8d8d8"},{"url":"https://git.kernel.org/stable/c/e30453c61e185e914fde83c650e268067b140218"}],"title":"mm: shrinker: fix NULL pointer dereference in debugfs","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-64417","datePublished":"2026-07-25T08:50:56.800Z","dateReserved":"2026-07-19T15:36:31.786Z","dateUpdated":"2026-07-25T08:50:56.800Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-25 10:17:25","lastModifiedDate":"2026-07-25 10:17:25","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"64417","Ordinal":"1","Title":"mm: shrinker: fix NULL pointer dereference in debugfs","CVE":"CVE-2026-64417","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"64417","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm: shrinker: fix NULL pointer dereference in debugfs\n\nshrinker_debugfs_add() creates both \"count\" and \"scan\" debugfs files\nunconditionally.\n\nThat assumes every shrinker implements both count_objects() and\nscan_objects(), which is not guaranteed.  For example, the xen-backend\nshrinker sets count_objects() but leaves scan_objects() NULL, so writing\nto its scan file calls through a NULL function pointer and panics the\nkernel:\n\nBUG: kernel NULL pointer dereference, address: 0000000000000000\nRIP: 0010:0x0\nCode: Unable to access opcode bytes at 0xffffffffffffffd6.\nCall Trace:\n <TASK>\n shrinker_debugfs_scan_write+0x12e/0x270\n full_proxy_write+0x5f/0x90\n vfs_write+0xde/0x420\n ? filp_flush+0x75/0x90\n ? filp_close+0x1d/0x30\n ? do_dup2+0xb8/0x120\n ksys_write+0x68/0xf0\n ? filp_flush+0x75/0x90\n do_syscall_64+0xb3/0x5b0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nThe count path has the same issue in principle if a shrinker omits\ncount_objects().\n\nTo fix it, only create \"count\" and \"scan\" debugfs files when the\ncorresponding callbacks are present.","Type":"Description","Title":"mm: shrinker: fix NULL pointer dereference in debugfs"}]}}}