{"id":"CVE-2026-80697","state":"PUBLISHED","title":"erofs: ensure valid f_path for page cache sharing","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nerofs: ensure valid f_path for page cache sharing\n\nPreviously, backing files for page cache sharing were set up with\nf_path left as NULL (only f_inode was valid).  It worked, but a recent\nmincore fix relies on f_path.mnt and crashes (found by \"erofs/028\" on\n7.2-rc4):\n\n BUG: kernel NULL pointer dereference, address: 0000000000000018\n #PF: supervisor read access in kernel mode\n #PF: error_code(0x0000) - not-present page\n PGD 0 P4D 0\n Oops: Oops: 0000 [#1] SMP PTI\n CPU: 3 UID: 0 PID: 675528 Comm: fincore Not tainted 7.2.0-rc4-00002-g[]-dirty #1 PREEMPT(lazy)\n Hardware name: Red Hat KVM, BIOS 1.16.0-4.al8 04/01/2014\n RIP: 0010:__do_sys_mincore+0xc0/0x2c0\n ...\n\nSpecify valid paths using valid disconnected dentries together with\nerofs_ishare_mnt instead of leaving f_path empty, so they are more\nlike real backing files in a pseudo filesystem and standard\nbacking_file_open() can be used directly.","publishedAt":"2026-08-28T06:53:02.236Z","updatedAt":"2026-08-28T12:08:17.218Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"5ef3208e3be50aa08b4e7a2832f34e16d42c08b3","status":"affected","lessThan":"3879657c4ffd81b9a42cf575fc6cb60201032587","versionType":"git"},{"version":"5ef3208e3be50aa08b4e7a2832f34e16d42c08b3","status":"affected","lessThan":"96b2dbbe58a1ea5df8d29c2fe24b5f04715f4443","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/erofs/Kconfig","fs/erofs/internal.h","fs/erofs/ishare.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"7.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"7.0","versionType":"semver"},{"version":"7.1.8","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/erofs/Kconfig","fs/erofs/internal.h","fs/erofs/ishare.c"]}],"references":["https://git.kernel.org/stable/c/3879657c4ffd81b9a42cf575fc6cb60201032587","https://git.kernel.org/stable/c/96b2dbbe58a1ea5df8d29c2fe24b5f04715f4443"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:07.220Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/80xxx/CVE-2026-80697.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-80697","state":"PUBLISHED","datePublished":"2026-08-28T06:53:02.236Z","dateUpdated":"2026-08-28T12:08:17.218Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-26T14:34:25.786Z"},"containers":{"cna":{"title":"erofs: ensure valid f_path for page cache sharing","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nerofs: ensure valid f_path for page cache sharing\n\nPreviously, backing files for page cache sharing were set up with\nf_path left as NULL (only f_inode was valid).  It worked, but a recent\nmincore fix relies on f_path.mnt and crashes (found by \"erofs/028\" on\n7.2-rc4):\n\n BUG: kernel NULL pointer dereference, address: 0000000000000018\n #PF: supervisor read access in kernel mode\n #PF: error_code(0x0000) - not-present page\n PGD 0 P4D 0\n Oops: Oops: 0000 [#1] SMP PTI\n CPU: 3 UID: 0 PID: 675528 Comm: fincore Not tainted 7.2.0-rc4-00002-g[]-dirty #1 PREEMPT(lazy)\n Hardware name: Red Hat KVM, BIOS 1.16.0-4.al8 04/01/2014\n RIP: 0010:__do_sys_mincore+0xc0/0x2c0\n ...\n\nSpecify valid paths using valid disconnected dentries together with\nerofs_ishare_mnt instead of leaving f_path empty, so they are more\nlike real backing files in a pseudo filesystem and standard\nbacking_file_open() can be used directly."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"5ef3208e3be50aa08b4e7a2832f34e16d42c08b3","status":"affected","lessThan":"3879657c4ffd81b9a42cf575fc6cb60201032587","versionType":"git"},{"version":"5ef3208e3be50aa08b4e7a2832f34e16d42c08b3","status":"affected","lessThan":"96b2dbbe58a1ea5df8d29c2fe24b5f04715f4443","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/erofs/Kconfig","fs/erofs/internal.h","fs/erofs/ishare.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"7.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"7.0","versionType":"semver"},{"version":"7.1.8","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/erofs/Kconfig","fs/erofs/internal.h","fs/erofs/ishare.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/3879657c4ffd81b9a42cf575fc6cb60201032587"},{"url":"https://git.kernel.org/stable/c/96b2dbbe58a1ea5df8d29c2fe24b5f04715f4443"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-28T12:08:17.218Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.0","versionEndExcluding":"7.1.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.0","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}