{"id":"CVE-2026-98451","state":"PUBLISHED","title":"smb: client: use finish_no_open() for non-regular inodes","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: use finish_no_open() for non-regular inodes\n\nAn O_CREAT open can find an existing symlink or another non-regular\ninode. cifs_atomic_open() calls finish_open() on it and attaches a\ncifsFileInfo. Symlink inodes have no CIFS release operation, so the\ndentry reference held by cifsFileInfo is leaked. FMODE_OPENED also\nprevents the VFS from following the symlink.\n\nTrack whether cifs_do_create() returned an open server handle. For\nnon-regular inodes, close the handle if present, remove the pending\nopen, and call finish_no_open() so the VFS can continue the lookup.\nDo not set FMODE_CREATED unless a regular file was opened. For\nO_NOFOLLOW with __O_REGULAR, return -ELOOP before the VFS's\n-EFTYPE check.\n\nDefer closing a legacy POSIX handle on a non-regular inode until\nafter inode lookup. This avoids closing it again if lookup fails.","publishedAt":"2026-10-18T15:15:01.473Z","updatedAt":"2026-10-30T12:38:11.067Z","severity":{"score":8.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d2c127197dfc0b2bae62a52e1e0d3e3ff493919e","status":"affected","lessThan":"bc585d5a381ab49cb611c35dda93a997214ca874","versionType":"git"},{"version":"d2c127197dfc0b2bae62a52e1e0d3e3ff493919e","status":"affected","lessThan":"26f4bca335e719e291995e28dc434de0145a6a54","versionType":"git"},{"version":"d2c127197dfc0b2bae62a52e1e0d3e3ff493919e","status":"affected","lessThan":"51c7b0593f6eaba05349fd2a01a9cb4df7d7412f","versionType":"git"},{"version":"d2c127197dfc0b2bae62a52e1e0d3e3ff493919e","status":"affected","lessThan":"045532f920d86dd76600b635f9756e5fd671ddfc","versionType":"git"},{"version":"d2c127197dfc0b2bae62a52e1e0d3e3ff493919e","status":"affected","lessThan":"ed03d547598c92a036f20e89156540995cac889a","versionType":"git"},{"version":"d2c127197dfc0b2bae62a52e1e0d3e3ff493919e","status":"affected","lessThan":"70a7918fda54a06d836acc91eb9a3c7e860fe0a0","versionType":"git"},{"version":"d2c127197dfc0b2bae62a52e1e0d3e3ff493919e","status":"affected","lessThan":"3c07deb26273155c180aedfd9041ab58015d2521","versionType":"git"},{"version":"d2c127197dfc0b2bae62a52e1e0d3e3ff493919e","status":"affected","lessThan":"e66cf1625ec4a3fe68346119f371def713fd0a4d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/dir.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.6","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.113","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.56","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.9","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/smb/client/dir.c"]}],"references":["https://git.kernel.org/stable/c/bc585d5a381ab49cb611c35dda93a997214ca874","https://git.kernel.org/stable/c/26f4bca335e719e291995e28dc434de0145a6a54","https://git.kernel.org/stable/c/51c7b0593f6eaba05349fd2a01a9cb4df7d7412f","https://git.kernel.org/stable/c/045532f920d86dd76600b635f9756e5fd671ddfc","https://git.kernel.org/stable/c/ed03d547598c92a036f20e89156540995cac889a","https://git.kernel.org/stable/c/70a7918fda54a06d836acc91eb9a3c7e860fe0a0","https://git.kernel.org/stable/c/3c07deb26273155c180aedfd9041ab58015d2521","https://git.kernel.org/stable/c/e66cf1625ec4a3fe68346119f371def713fd0a4d"],"weaknesses":[],"ingestedAt":"2026-10-30T12:58:04.520Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98451.json","commit":"1f312381e38164a43607eebab851b151dd16861e","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98451","state":"PUBLISHED","datePublished":"2026-10-18T15:15:01.473Z","dateUpdated":"2026-10-30T12:38:11.067Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.350Z"},"containers":{"cna":{"title":"smb: client: use finish_no_open() for non-regular inodes","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: use finish_no_open() for non-regular inodes\n\nAn O_CREAT open can find an existing symlink or another non-regular\ninode. cifs_atomic_open() calls finish_open() on it and attaches a\ncifsFileInfo. Symlink inodes have no CIFS release operation, so the\ndentry reference held by cifsFileInfo is leaked. FMODE_OPENED also\nprevents the VFS from following the symlink.\n\nTrack whether cifs_do_create() returned an open server handle. For\nnon-regular inodes, close the handle if present, remove the pending\nopen, and call finish_no_open() so the VFS can continue the lookup.\nDo not set FMODE_CREATED unless a regular file was opened. For\nO_NOFOLLOW with __O_REGULAR, return -ELOOP before the VFS's\n-EFTYPE check.\n\nDefer closing a legacy POSIX handle on a non-regular inode until\nafter inode lookup. This avoids closing it again if lookup fails."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d2c127197dfc0b2bae62a52e1e0d3e3ff493919e","status":"affected","lessThan":"bc585d5a381ab49cb611c35dda93a997214ca874","versionType":"git"},{"version":"d2c127197dfc0b2bae62a52e1e0d3e3ff493919e","status":"affected","lessThan":"26f4bca335e719e291995e28dc434de0145a6a54","versionType":"git"},{"version":"d2c127197dfc0b2bae62a52e1e0d3e3ff493919e","status":"affected","lessThan":"51c7b0593f6eaba05349fd2a01a9cb4df7d7412f","versionType":"git"},{"version":"d2c127197dfc0b2bae62a52e1e0d3e3ff493919e","status":"affected","lessThan":"045532f920d86dd76600b635f9756e5fd671ddfc","versionType":"git"},{"version":"d2c127197dfc0b2bae62a52e1e0d3e3ff493919e","status":"affected","lessThan":"ed03d547598c92a036f20e89156540995cac889a","versionType":"git"},{"version":"d2c127197dfc0b2bae62a52e1e0d3e3ff493919e","status":"affected","lessThan":"70a7918fda54a06d836acc91eb9a3c7e860fe0a0","versionType":"git"},{"version":"d2c127197dfc0b2bae62a52e1e0d3e3ff493919e","status":"affected","lessThan":"3c07deb26273155c180aedfd9041ab58015d2521","versionType":"git"},{"version":"d2c127197dfc0b2bae62a52e1e0d3e3ff493919e","status":"affected","lessThan":"e66cf1625ec4a3fe68346119f371def713fd0a4d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/dir.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.6","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.113","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.56","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.9","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/smb/client/dir.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/bc585d5a381ab49cb611c35dda93a997214ca874"},{"url":"https://git.kernel.org/stable/c/26f4bca335e719e291995e28dc434de0145a6a54"},{"url":"https://git.kernel.org/stable/c/51c7b0593f6eaba05349fd2a01a9cb4df7d7412f"},{"url":"https://git.kernel.org/stable/c/045532f920d86dd76600b635f9756e5fd671ddfc"},{"url":"https://git.kernel.org/stable/c/ed03d547598c92a036f20e89156540995cac889a"},{"url":"https://git.kernel.org/stable/c/70a7918fda54a06d836acc91eb9a3c7e860fe0a0"},{"url":"https://git.kernel.org/stable/c/3c07deb26273155c180aedfd9041ab58015d2521"},{"url":"https://git.kernel.org/stable/c/e66cf1625ec4a3fe68346119f371def713fd0a4d"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","baseScore":8.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - `openat(O_CREAT)` reaches `cifs_atomic_open()` and `cifs_do_create()`; a remote SMB2 server can return a CREATE/reparse response identifying the object as `IO_REPARSE_TAG_LX_FIFO`, so the causative inode type arrives over routable SMB.\nAC:L - The server can return a FIFO for any fresh, uncached requested name; after the victim's O_CREAT, `finish_open()` and `cifs_new_fileinfo()` deterministically create the type confusion without a race or an uncontrollable precondition.\nPR:N - A malicious SMB endpoint needs no account or capability on the client; the SMB session authenticates the victim outward to the server, which directly controls the CREATE and reparse responses.\nUI:R - The remote server cannot initiate `cifs_atomic_open()` itself; a victim must mount or access its share and issue an O_CREAT open, after which the server can substitute the non-regular inode response.\nS:U - The confused `cifsFileInfo` and resulting pipe operations execute within the vulnerable client's kernel security authority and do not cross a VM, IOMMU, or other security boundary.\nC:H - `cifs_set_ops()` installs `pipefifo_fops`, but `finish_open(..., generic_file_open)` skips `fifo_open()` and `cifs_new_fileinfo()` puts a `cifsFileInfo` in `private_data`; `fifo_pipe_read()` then treats its fields as pipe buffers and pages, creating disclosure-capable type confusion.\nI:H - `pipe_release()` and `pipe_resize_ring()` treat the `cifsFileInfo` as `pipe_inode_info`, modifying fake mutex, counter, waitqueue, and buffer-pointer fields and potentially freeing the misinterpreted `pipe->bufs`, providing kernel-memory corruption primitives.\nA:H - Closing the returned FIFO fd invokes `pipe_release()` on the `cifsFileInfo`; locking its list pointers as a pipe mutex and accessing fake pipe state can immediately oops or hang the kernel, beyond the separate symlink reference leak."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:38:11.067Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.6","versionEndExcluding":"5.10.273"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.6","versionEndExcluding":"5.15.224"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.6","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.6","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.6","versionEndExcluding":"6.12.113"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.6","versionEndExcluding":"6.18.56"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.6","versionEndExcluding":"7.2.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.6","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}