{"id":"CVE-2026-89839","state":"PUBLISHED","title":"f2fs: use the mount idmap for the owner check in f2fs_xattr_advise_set()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: use the mount idmap for the owner check in f2fs_xattr_advise_set()\n\nf2fs_xattr_advise_set() calls inode_owner_or_capable() with &nop_mnt_idmap\nbefore allowing the \"system.advise\" xattr to be set, instead of the idmap\nthat the VFS passes to the ->set() handler.\n\nf2fs supports idmapped mounts, so on such a mount this checks the caller's\nfsuid against the unmapped on-disk owner rather than the mapped owner: the\nactual owner can be wrongly denied with -EPERM and an unrelated caller\nwrongly allowed.  Pass the handler's idmap instead.","publishedAt":"2026-09-16T10:31:13.727Z","updatedAt":"2026-10-19T08:53:32.430Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"01beba7957a26f9b7179127e8ad56bb5a0f56138","status":"affected","lessThan":"4c0c610b480cfbc57528aa1acbd6be12ed2a6fb1","versionType":"git"},{"version":"01beba7957a26f9b7179127e8ad56bb5a0f56138","status":"affected","lessThan":"c3e2692c7a58e0bdb84bd658d827e89dcecea3ad","versionType":"git"},{"version":"01beba7957a26f9b7179127e8ad56bb5a0f56138","status":"affected","lessThan":"3b681229e9f8fb1dd29bc65983bf3c87779e4ca3","versionType":"git"},{"version":"01beba7957a26f9b7179127e8ad56bb5a0f56138","status":"affected","lessThan":"ab31e3b774f5d06b4489cef6c297b48c47c9dcbd","versionType":"git"},{"version":"01beba7957a26f9b7179127e8ad56bb5a0f56138","status":"affected","lessThan":"a54ffce4637acb0db8e695188a6c7f99f14c3576","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/xattr.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.3","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.110","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.51","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.5","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/xattr.c"]}],"references":["https://git.kernel.org/stable/c/4c0c610b480cfbc57528aa1acbd6be12ed2a6fb1","https://git.kernel.org/stable/c/c3e2692c7a58e0bdb84bd658d827e89dcecea3ad","https://git.kernel.org/stable/c/3b681229e9f8fb1dd29bc65983bf3c87779e4ca3","https://git.kernel.org/stable/c/ab31e3b774f5d06b4489cef6c297b48c47c9dcbd","https://git.kernel.org/stable/c/a54ffce4637acb0db8e695188a6c7f99f14c3576"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:26.108Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/89xxx/CVE-2026-89839.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89839","state":"PUBLISHED","datePublished":"2026-09-16T10:31:13.727Z","dateUpdated":"2026-10-19T08:53:32.430Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.769Z"},"containers":{"cna":{"title":"f2fs: use the mount idmap for the owner check in f2fs_xattr_advise_set()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: use the mount idmap for the owner check in f2fs_xattr_advise_set()\n\nf2fs_xattr_advise_set() calls inode_owner_or_capable() with &nop_mnt_idmap\nbefore allowing the \"system.advise\" xattr to be set, instead of the idmap\nthat the VFS passes to the ->set() handler.\n\nf2fs supports idmapped mounts, so on such a mount this checks the caller's\nfsuid against the unmapped on-disk owner rather than the mapped owner: the\nactual owner can be wrongly denied with -EPERM and an unrelated caller\nwrongly allowed.  Pass the handler's idmap instead."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"01beba7957a26f9b7179127e8ad56bb5a0f56138","status":"affected","lessThan":"4c0c610b480cfbc57528aa1acbd6be12ed2a6fb1","versionType":"git"},{"version":"01beba7957a26f9b7179127e8ad56bb5a0f56138","status":"affected","lessThan":"c3e2692c7a58e0bdb84bd658d827e89dcecea3ad","versionType":"git"},{"version":"01beba7957a26f9b7179127e8ad56bb5a0f56138","status":"affected","lessThan":"3b681229e9f8fb1dd29bc65983bf3c87779e4ca3","versionType":"git"},{"version":"01beba7957a26f9b7179127e8ad56bb5a0f56138","status":"affected","lessThan":"ab31e3b774f5d06b4489cef6c297b48c47c9dcbd","versionType":"git"},{"version":"01beba7957a26f9b7179127e8ad56bb5a0f56138","status":"affected","lessThan":"a54ffce4637acb0db8e695188a6c7f99f14c3576","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/xattr.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.3","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.110","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.51","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.5","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/xattr.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/4c0c610b480cfbc57528aa1acbd6be12ed2a6fb1"},{"url":"https://git.kernel.org/stable/c/c3e2692c7a58e0bdb84bd658d827e89dcecea3ad"},{"url":"https://git.kernel.org/stable/c/3b681229e9f8fb1dd29bc65983bf3c87779e4ca3"},{"url":"https://git.kernel.org/stable/c/ab31e3b774f5d06b4489cef6c297b48c47c9dcbd"},{"url":"https://git.kernel.org/stable/c/a54ffce4637acb0db8e695188a6c7f99f14c3576"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T08:53:32.430Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.3","versionEndExcluding":"6.6.157"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.3","versionEndExcluding":"6.12.110"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.3","versionEndExcluding":"6.18.51"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.3","versionEndExcluding":"7.2.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.3","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}