{"api_version":"1","generated_at":"2026-09-21T13:23:08+00:00","cve":"CVE-2026-90139","urls":{"html":"https://cve.report/CVE-2026-90139","api":"https://cve.report/api/cve/CVE-2026-90139.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-90139","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-90139"},"summary":{"title":"fuse: check for NULL root inode in fuse_fill_super_submount","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfuse: check for NULL root inode in fuse_fill_super_submount\n\nfuse_iget() can return NULL when its inode allocation fails, but\nfuse_fill_super_submount() passed the result straight to get_fuse_inode()\nand decremented fi->nlookup without checking it:\n\n        root = fuse_iget(sb, parent_fi->nodeid, ...);\n        fi = get_fuse_inode(root);\n        fi->nlookup--;\n\nInside fuse_iget() the inode allocation can fail and return NULL.  The\nsubmount root takes the iget5_locked() path, whose alloc_inode() can fail\nunder memory pressure (the auto-submount branch can fail the same way in\nnew_inode() or fuse_alloc_submount_lookup()):\n\n        inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set,\n                             &nodeid);\n        if (!inode)\n                return NULL;\n\nA NULL root makes get_fuse_inode() a container_of() on NULL and the\nnlookup decrement a write to a bogus address, oopsing the mount.  With\nCONFIG_KASAN the following null pointer dereference is reported when the\nroot inode allocation of an auto-submount fails (e.g. under memory\npressure):\n\n==================================================================\nBUG: KASAN: null-ptr-deref in fuse_get_tree_submount+0x656/0x8b0\nRead of size 8 at addr 00000000000002b0 by task ls/942\nCPU: 0 PID: 942 Comm: ls Tainted: G W 6.6 #15\nCall Trace:\n <TASK>\n fuse_get_tree_submount+0x656/0x8b0\n vfs_get_tree+0x48/0x140\n fc_mount+0x13/0x50\n fuse_dentry_automount+0x7a/0xb0\n __traverse_mounts+0xca/0x330\n step_into+0x339/0xac0\n path_lookupat+0xc5/0x2f0\n filename_lookup+0x163/0x2a0\n vfs_statx+0xd5/0x200\n do_statx+0x83/0xd0\n __x64_sys_statx+0xa0/0xc0\n do_syscall_64+0x37/0x90\n entry_SYSCALL_64_after_hwframe+0x78/0xe2\n </TASK>\n==================================================================\n\nReturn -ENOMEM instead; the caller tears down the partially built\nsuperblock on error, matching the other error returns in this\nfunction.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-17 17:17:06","updated_at":"2026-09-17 17:17:06"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/928f659a3e3650978a5b4829cc982324f72b474b","name":"https://git.kernel.org/stable/c/928f659a3e3650978a5b4829cc982324f72b474b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a5129155ca9fba40d77ff19ffead8244e88d6f9c","name":"https://git.kernel.org/stable/c/a5129155ca9fba40d77ff19ffead8244e88d6f9c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/17120c5bfb16808509ea18d7fab6027802d93eba","name":"https://git.kernel.org/stable/c/17120c5bfb16808509ea18d7fab6027802d93eba","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/509f4a09bae7f03c87f67f053648874a5e177867","name":"https://git.kernel.org/stable/c/509f4a09bae7f03c87f67f053648874a5e177867","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e0b7f2922f6bd4c23cbddb7d1fc2bada570d27d1","name":"https://git.kernel.org/stable/c/e0b7f2922f6bd4c23cbddb7d1fc2bada570d27d1","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-90139","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90139","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1866d779d5d2abae59d304e809600ca3ca8d0071 17120c5bfb16808509ea18d7fab6027802d93eba git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1866d779d5d2abae59d304e809600ca3ca8d0071 e0b7f2922f6bd4c23cbddb7d1fc2bada570d27d1 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1866d779d5d2abae59d304e809600ca3ca8d0071 a5129155ca9fba40d77ff19ffead8244e88d6f9c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1866d779d5d2abae59d304e809600ca3ca8d0071 509f4a09bae7f03c87f67f053648874a5e177867 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1866d779d5d2abae59d304e809600ca3ca8d0071 928f659a3e3650978a5b4829cc982324f72b474b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.10","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.10 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.157 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.110 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.52 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.6 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/fuse/inode.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"17120c5bfb16808509ea18d7fab6027802d93eba","status":"affected","version":"1866d779d5d2abae59d304e809600ca3ca8d0071","versionType":"git"},{"lessThan":"e0b7f2922f6bd4c23cbddb7d1fc2bada570d27d1","status":"affected","version":"1866d779d5d2abae59d304e809600ca3ca8d0071","versionType":"git"},{"lessThan":"a5129155ca9fba40d77ff19ffead8244e88d6f9c","status":"affected","version":"1866d779d5d2abae59d304e809600ca3ca8d0071","versionType":"git"},{"lessThan":"509f4a09bae7f03c87f67f053648874a5e177867","status":"affected","version":"1866d779d5d2abae59d304e809600ca3ca8d0071","versionType":"git"},{"lessThan":"928f659a3e3650978a5b4829cc982324f72b474b","status":"affected","version":"1866d779d5d2abae59d304e809600ca3ca8d0071","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/fuse/inode.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.10"},{"lessThan":"5.10","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.157","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.110","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.52","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.6","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.157","versionStartIncluding":"5.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.110","versionStartIncluding":"5.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.52","versionStartIncluding":"5.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.6","versionStartIncluding":"5.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"5.10","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nfuse: check for NULL root inode in fuse_fill_super_submount\n\nfuse_iget() can return NULL when its inode allocation fails, but\nfuse_fill_super_submount() passed the result straight to get_fuse_inode()\nand decremented fi->nlookup without checking it:\n\n        root = fuse_iget(sb, parent_fi->nodeid, ...);\n        fi = get_fuse_inode(root);\n        fi->nlookup--;\n\nInside fuse_iget() the inode allocation can fail and return NULL.  The\nsubmount root takes the iget5_locked() path, whose alloc_inode() can fail\nunder memory pressure (the auto-submount branch can fail the same way in\nnew_inode() or fuse_alloc_submount_lookup()):\n\n        inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set,\n                             &nodeid);\n        if (!inode)\n                return NULL;\n\nA NULL root makes get_fuse_inode() a container_of() on NULL and the\nnlookup decrement a write to a bogus address, oopsing the mount.  With\nCONFIG_KASAN the following null pointer dereference is reported when the\nroot inode allocation of an auto-submount fails (e.g. under memory\npressure):\n\n==================================================================\nBUG: KASAN: null-ptr-deref in fuse_get_tree_submount+0x656/0x8b0\nRead of size 8 at addr 00000000000002b0 by task ls/942\nCPU: 0 PID: 942 Comm: ls Tainted: G W 6.6 #15\nCall Trace:\n <TASK>\n fuse_get_tree_submount+0x656/0x8b0\n vfs_get_tree+0x48/0x140\n fc_mount+0x13/0x50\n fuse_dentry_automount+0x7a/0xb0\n __traverse_mounts+0xca/0x330\n step_into+0x339/0xac0\n path_lookupat+0xc5/0x2f0\n filename_lookup+0x163/0x2a0\n vfs_statx+0xd5/0x200\n do_statx+0x83/0xd0\n __x64_sys_statx+0xa0/0xc0\n do_syscall_64+0x37/0x90\n entry_SYSCALL_64_after_hwframe+0x78/0xe2\n </TASK>\n==================================================================\n\nReturn -ENOMEM instead; the caller tears down the partially built\nsuperblock on error, matching the other error returns in this\nfunction."}],"providerMetadata":{"dateUpdated":"2026-09-17T16:06:37.179Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/17120c5bfb16808509ea18d7fab6027802d93eba"},{"url":"https://git.kernel.org/stable/c/e0b7f2922f6bd4c23cbddb7d1fc2bada570d27d1"},{"url":"https://git.kernel.org/stable/c/a5129155ca9fba40d77ff19ffead8244e88d6f9c"},{"url":"https://git.kernel.org/stable/c/509f4a09bae7f03c87f67f053648874a5e177867"},{"url":"https://git.kernel.org/stable/c/928f659a3e3650978a5b4829cc982324f72b474b"}],"title":"fuse: check for NULL root inode in fuse_fill_super_submount","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-90139","datePublished":"2026-09-17T16:06:37.179Z","dateReserved":"2026-09-11T19:38:34.789Z","dateUpdated":"2026-09-17T16:06:37.179Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-17 17:17:06","lastModifiedDate":"2026-09-17 17:17:06","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"90139","Ordinal":"1","Title":"fuse: check for NULL root inode in fuse_fill_super_submount","CVE":"CVE-2026-90139","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"90139","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nfuse: check for NULL root inode in fuse_fill_super_submount\n\nfuse_iget() can return NULL when its inode allocation fails, but\nfuse_fill_super_submount() passed the result straight to get_fuse_inode()\nand decremented fi->nlookup without checking it:\n\n        root = fuse_iget(sb, parent_fi->nodeid, ...);\n        fi = get_fuse_inode(root);\n        fi->nlookup--;\n\nInside fuse_iget() the inode allocation can fail and return NULL.  The\nsubmount root takes the iget5_locked() path, whose alloc_inode() can fail\nunder memory pressure (the auto-submount branch can fail the same way in\nnew_inode() or fuse_alloc_submount_lookup()):\n\n        inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set,\n                             &nodeid);\n        if (!inode)\n                return NULL;\n\nA NULL root makes get_fuse_inode() a container_of() on NULL and the\nnlookup decrement a write to a bogus address, oopsing the mount.  With\nCONFIG_KASAN the following null pointer dereference is reported when the\nroot inode allocation of an auto-submount fails (e.g. under memory\npressure):\n\n==================================================================\nBUG: KASAN: null-ptr-deref in fuse_get_tree_submount+0x656/0x8b0\nRead of size 8 at addr 00000000000002b0 by task ls/942\nCPU: 0 PID: 942 Comm: ls Tainted: G W 6.6 #15\nCall Trace:\n <TASK>\n fuse_get_tree_submount+0x656/0x8b0\n vfs_get_tree+0x48/0x140\n fc_mount+0x13/0x50\n fuse_dentry_automount+0x7a/0xb0\n __traverse_mounts+0xca/0x330\n step_into+0x339/0xac0\n path_lookupat+0xc5/0x2f0\n filename_lookup+0x163/0x2a0\n vfs_statx+0xd5/0x200\n do_statx+0x83/0xd0\n __x64_sys_statx+0xa0/0xc0\n do_syscall_64+0x37/0x90\n entry_SYSCALL_64_after_hwframe+0x78/0xe2\n </TASK>\n==================================================================\n\nReturn -ENOMEM instead; the caller tears down the partially built\nsuperblock on error, matching the other error returns in this\nfunction.","Type":"Description","Title":"fuse: check for NULL root inode in fuse_fill_super_submount"}]}}}