{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64417","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-07-19T15:36:31.786Z","datePublished":"2026-07-25T08:50:56.800Z","dateUpdated":"2026-08-17T04:55:16.708Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-17T04:55:16.708Z"},"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."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/shrinker_debug.c"],"versions":[{"version":"bbf535fd6f06b94b9d07ed6f09397a936d4a58d8","lessThan":"ebb45c2648b1f60715fd283700f651e05e431231","status":"affected","versionType":"git"},{"version":"bbf535fd6f06b94b9d07ed6f09397a936d4a58d8","lessThan":"09d2407985b8ce3e831f9d4310fe7ac06a6b3ae9","status":"affected","versionType":"git"},{"version":"bbf535fd6f06b94b9d07ed6f09397a936d4a58d8","lessThan":"36f8534f461222291a74156ab91f3ba9f09b6f93","status":"affected","versionType":"git"},{"version":"bbf535fd6f06b94b9d07ed6f09397a936d4a58d8","lessThan":"006467ab932698612398f853344a7405164541f4","status":"affected","versionType":"git"},{"version":"bbf535fd6f06b94b9d07ed6f09397a936d4a58d8","lessThan":"b9beed2322f3538b0d2d53307062da4102b8d8d8","status":"affected","versionType":"git"},{"version":"bbf535fd6f06b94b9d07ed6f09397a936d4a58d8","lessThan":"e30453c61e185e914fde83c650e268067b140218","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/shrinker_debug.c"],"versions":[{"version":"6.0","status":"affected"},{"version":"0","lessThan":"6.0","status":"unaffected","versionType":"semver"},{"version":"6.1.178","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.145","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.96","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.39","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.4","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.1.178"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.12.96"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.18.39"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"7.1.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"7.2"}]}]}],"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"}}}}