CVE-2026-64398

CVE-2026-64398 affects the Linux kernel ksmbd component. A permission check bypass in FSCTL_SET_ZERO_DATA allows an authenticated SMB client with only FILE_WRITE_ATTRIBUTES to zero out file data via fsctl path, bypassing per-handle checks. The operation uses vfs_fallocate(PUNCH_HOLE/ZERO_RANGE) a...

CVE-2026-64398 ksmbd: add a permission check for FSCTL_SET_ZERO_DATA

In the Linux kernel, the following vulnerability has been resolved: ksmbd: add a permission check for FSCTLSETZERODATA FSCTLSETZERODATA in smb2ioctl destroys file data via ksmbdvfszerodata - vfsfallocatePUNCHHOLE/ZERORANGE after checking only the share-level KSMBDTREECONNFLAGWRITABLE, with no...

CVE-2026-64399

Summary: CVE-2026-64399 affects the Linux kernel ksmbd path for FSCTL_DUPLICATE_EXTENTS_TO_FILE. The vulnerability allows overwriting a destination file’s data via vfs_clone_file_range() because both the share-level KSMBD_TREE_CONN_FLAG_WRITABLE check and a per-handle daccess check were absent, a...

EUVD-2026-48942

In the Linux kernel, the following vulnerability has been resolved: ksmbd: add a permission check for FSCTLSETZERODATA FSCTLSETZERODATA in smb2ioctl destroys file data via ksmbdvfszerodata - vfsfallocatePUNCHHOLE/ZERORANGE after checking only the share-level KSMBDTREECONNFLAGWRITABLE, with no...

CVE-2026-64398

In the Linux kernel, the following vulnerability has been resolved: ksmbd: add a permission check for FSCTLSETZERODATA FSCTLSETZERODATA in smb2ioctl destroys file data via ksmbdvfszerodata - vfsfallocatePUNCHHOLE/ZERORANGE after checking only the share-level KSMBDTREECONNFLAGWRITABLE, with no...

CVE-2026-64399 ksmbd: add permission checks for FSCTL_DUPLICATE_EXTENTS_TO_FILE

In the Linux kernel, the following vulnerability has been resolved: ksmbd: add permission checks for FSCTLDUPLICATEEXTENTSTOFILE The FSCTLDUPLICATEEXTENTSTOFILE arm of smb2ioctl overwrites the destination file's data via vfsclonefilerange with neither the share-level KSMBDTREECONNFLAGWRITABLE che...

CVE-2026-64398

In the Linux kernel, the following vulnerability has been resolved: ksmbd: add a permission check for FSCTLSETZERODATA FSCTLSETZERODATA in smb2ioctl destroys file data via ksmbdvfszerodata - vfsfallocatePUNCHHOLE/ZERORANGE after checking only the share-level KSMBDTREECONNFLAGWRITABLE, with no...

CVE-2026-64398 ksmbd: add a permission check for FSCTL_SET_ZERO_DATA

In the Linux kernel, the following vulnerability has been resolved: ksmbd: add a permission check for FSCTLSETZERODATA FSCTLSETZERODATA in smb2ioctl destroys file data via ksmbdvfszerodata - vfsfallocatePUNCHHOLE/ZERORANGE after checking only the share-level KSMBDTREECONNFLAGWRITABLE, with no...

CVE-2026-64397 ksmbd: serialize QUERY_DIRECTORY requests per file

In the Linux kernel, the following vulnerability has been resolved: ksmbd: serialize QUERYDIRECTORY requests per file smb2querydir stores a pointer to its stack-allocated private data in the ksmbdfile readdirdata. Concurrent QUERYDIRECTORY requests using the same file handle can overwrite this...

CVE-2026-64397

CVE-2026-64397 affects the Linux kernel ksmbd component. The issue arises in smb2_query_dir() which stores a pointer to stack-allocated private data in ksmbd_file readdir_data; concurrent QUERY_DIRECTORY requests using the same file handle can overwrite this pointer while an iterate_dir() callbac...

CVE-2026-64397

In the Linux kernel, the following vulnerability has been resolved: ksmbd: serialize QUERYDIRECTORY requests per file smb2querydir stores a pointer to its stack-allocated private data in the ksmbdfile readdirdata. Concurrent QUERYDIRECTORY requests using the same file handle can overwrite this...

CVE-2026-64397 ksmbd: serialize QUERY_DIRECTORY requests per file

In the Linux kernel, the following vulnerability has been resolved: ksmbd: serialize QUERYDIRECTORY requests per file smb2querydir stores a pointer to its stack-allocated private data in the ksmbdfile readdirdata. Concurrent QUERYDIRECTORY requests using the same file handle can overwrite this...

CVE-2026-64397

In the Linux kernel, the following vulnerability has been resolved: ksmbd: serialize QUERYDIRECTORY requests per file smb2querydir stores a pointer to its stack-allocated private data in the ksmbdfile readdirdata. Concurrent QUERYDIRECTORY requests using the same file handle can overwrite this...

CVE-2026-64396 ksmbd: fix UAF of struct file_lock in SMB2_LOCK deferred-lock cancellation

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix UAF of struct filelock in SMB2LOCK deferred-lock cancellation When a blocking byte-range lock request is deferred in the FILELOCKDEFERRED path, ksmbd registers the asynchronous work into the connection's asyncrequests...

CVE-2026-64396 ksmbd: fix UAF of struct file_lock in SMB2_LOCK deferred-lock cancellation

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix UAF of struct filelock in SMB2LOCK deferred-lock cancellation When a blocking byte-range lock request is deferred in the FILELOCKDEFERRED path, ksmbd registers the asynchronous work into the connection's asyncrequests...

CVE-2026-64395

In the Linux kernel, the following vulnerability has been resolved: ksmbd: require source read access for duplicate extents FSCTLDUPLICATEEXTENTSTOFILE passes the source file directly to vfsclonefilerange or vfscopyfilerange without checking the SMB access mask granted to the source handle. A...

CVE-2026-64396

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix UAF of struct filelock in SMB2LOCK deferred-lock cancellation When a blocking byte-range lock request is deferred in the FILELOCKDEFERRED path, ksmbd registers the asynchronous work into the connection's asyncrequests...

CVE-2026-64393

In the Linux kernel, the following vulnerability has been resolved: ksmbd: run set info with opener credentials SMB2 SETINFO handlers call path-based VFS helpers after checking the access mask granted to the SMB handle. Those helpers perform their owner, inode permission and LSM checks using the...

CVE-2026-64394 ksmbd: add a WRITE_DAC/WRITE_OWNER check to SMB2 SET_INFO SECURITY

In the Linux kernel, the following vulnerability has been resolved: ksmbd: add a WRITEDAC/WRITEOWNER check to SMB2 SETINFO SECURITY commit cc57232cae23 "ksmbd: fix FSCTL permission bypass by adding a permission check for FSCTLSETSPARSE" added a fp-daccess gate to fsctlsetsparse and noted that...

CVE-2026-64394 ksmbd: add a WRITE_DAC/WRITE_OWNER check to SMB2 SET_INFO SECURITY

In the Linux kernel, the following vulnerability has been resolved: ksmbd: add a WRITEDAC/WRITEOWNER check to SMB2 SETINFO SECURITY commit cc57232cae23 "ksmbd: fix FSCTL permission bypass by adding a permission check for FSCTLSETSPARSE" added a fp-daccess gate to fsctlsetsparse and noted that...