Linux: >> Linux Kernel >> 5.15.216 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: use opener credentials for ADS I/O
Alternate data streams are stored as xattrs. Unlike regular file I/O,
their read and write paths therefore call VFS xattr helpers which recheck
inode permissions and LSM policy using the current task credentials.
Run ADS I/O with the credentials captured when the SMB handle was opened.
CVSS Score
9.8
EPSS Score
0.005
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: use opener credentials for delete-on-close
Delete-on-close can be completed by deferred or durable handle teardown,
where no request work is available. Both the base-file unlink and the ADS
xattr removal consequently run with the ksmbd worker credentials and can
bypass filesystem permission checks.
Run both operations with the credentials captured in struct file when the
handle was opened. This preserves the authenticated user's fsuid, fsgid,
supplementary groups and capability restrictions at final close.
CVSS Score
9.1
EPSS Score
0.005
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: run set info with opener credentials
SMB2 SET_INFO 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 current ksmbd worker credentials.
Run the complete SET_INFO dispatch with the credentials captured when the
handle was opened. This also removes the separate security information
credential setup and keeps all SET_INFO classes under one credential scope.
Direct override_creds() is used because it can nest with the request
credential overrides already used by rename and link helpers.
CVSS Score
9.1
EPSS Score
0.005
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: add a WRITE_DAC/WRITE_OWNER check to SMB2 SET_INFO SECURITY
commit cc57232cae23 ("ksmbd: fix FSCTL permission bypass by adding a
permission check for FSCTL_SET_SPARSE") added a fp->daccess gate to
fsctl_set_sparse and noted that "similar handle-level checks exist in other
functions but are missing here." The SMB2 SET_INFO SECURITY arm is one of
the missing ones, and the most security-relevant: smb2_set_info_sec() calls
set_info_sec() with no per-handle access check.
set_info_sec() (fs/smb/server/smbacl.c) re-permissions the file: it
rewrites owner/group/mode via notify_change(), rewrites the POSIX ACL via
set_posix_acl(), and on KSMBD_SHARE_FLAG_ACL_XATTR shares removes and
rewrites the Windows security descriptor via ksmbd_vfs_set_sd_xattr().
Every other persistent-mutation arm of the sibling handler
smb2_set_info_file() checks fp->daccess first (FILE_WRITE_DATA /
FILE_DELETE / FILE_WRITE_EA / FILE_WRITE_ATTRIBUTES); the SECURITY arm —
which mutates the access control itself — is the only one with no gate.
A client can therefore open a handle with FILE_WRITE_ATTRIBUTES only (no
FILE_WRITE_DAC / FILE_WRITE_OWNER) and use SMB2_SET_INFO with InfoType
SMB2_O_INFO_SECURITY to rewrite the file's DACL and owner, granting itself
access the handle's daccess never carried. Unlike the FSCTL data arms this
is a metadata/xattr operation, so there is no FMODE_WRITE VFS backstop —
the missing fp->daccess check is the entire gate.
Setting a security descriptor is the WRITE_DAC / WRITE_OWNER operation, so
require at least one of those on the handle before re-permissioning the
file. -EACCES is mapped to STATUS_ACCESS_DENIED by smb2_set_info().
CVSS Score
8.8
EPSS Score
0.005
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: require source read access for duplicate extents
FSCTL_DUPLICATE_EXTENTS_TO_FILE passes the source file directly to
vfs_clone_file_range() or vfs_copy_file_range() without checking the SMB
access mask granted to the source handle. A handle opened with attribute
access can consequently be used to copy file contents into an
attacker-readable destination.
Require FILE_READ_DATA on the source handle before either VFS operation,
matching other ksmbd data-copy paths.
CVSS Score
7.5
EPSS Score
0.004
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
usb: free iso schedules on failed submit
EHCI and FOTG210 isochronous submits build an ehci_iso_sched before
linking the URB to the endpoint queue, and keep the staged schedule in
urb->hcpriv until iso_stream_schedule() and the link helpers consume it.
If the controller is no longer accessible, or usb_hcd_link_urb_to_ep()
fails, submit jumps to done_not_linked before that handoff happens and
leaks the staged schedule still attached to urb->hcpriv.
Free the staged schedule from done_not_linked when submit fails before
the URB is linked and clear urb->hcpriv after the free.
The bug was first flagged by an experimental analysis tool we are
developing for kernel memory-management bugs while analyzing
v6.13-rc1. The tool is still under development and is not yet publicly
available. Manual inspection confirms that the bug is still
present in v7.1.1.
An x86_64 allyesconfig build showed no new warnings. As we do not have an
EHCI host controller with a USB isochronous device to test with, no
runtime testing was able to be performed.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
USB: iowarrior: fix use-after-free on disconnect race
mutex_unlock() may access the mutex structure after releasing the lock
and therefore cannot be used to manage lifetime of objects directly
(unlike spinlocks and refcounts). [1][2]
Use a kref to release the driver data to avoid use-after-free in
mutex_unlock() when release() races with disconnect().
[1] a51749ab34d9 ("locking/mutex: Document that mutex_unlock() is non-atomic")
[2] 2b9d9e0a9ba0 ("locking/mutex: Clarify that mutex_unlock(), and most
other sleeping locks, can still use the lock object
after it's unlocked")
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_printer: take kref only for successful open
printer_open() returns -EBUSY when the character device is already
open, but it increments dev->kref regardless of the return value. VFS
does not call ->release() for a failed open, so every rejected second
open permanently leaks one reference.
Move kref_get() into the successful-open branch.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
nvmet: fix pre-auth out-of-bounds heap read in Discovery Get Log Page
nvmet_execute_disc_get_log_page() validates only the dword alignment
of the host-supplied Log Page Offset (lpo). The 64-bit offset is then
added to a small kzalloc'd buffer that holds the discovery log page
and the result is passed straight to nvmet_copy_to_sgl(), which
memcpy()s data_len bytes out to the host with no source-side bound
check:
u64 offset = nvmet_get_log_page_offset(req->cmd); /* 64-bit host */
size_t data_len = nvmet_get_log_page_len(req->cmd); /* 32-bit host */
...
if (offset & 0x3) { ... } /* only check */
...
alloc_len = sizeof(*hdr) + entry_size * discovery_log_entries(req);
buffer = kzalloc(alloc_len, GFP_KERNEL);
...
status = nvmet_copy_to_sgl(req, 0, buffer + offset, data_len);
The Discovery controller is unauthenticated -- nvmet_host_allowed()
returns true unconditionally for the discovery subsystem -- so the call
is reachable pre-authentication by any TCP/RDMA/FC peer that can reach
the nvmet target. With a discovery log page of ~1 KiB, an attacker
requesting up to 4 KiB starting at offset == alloc_len reads the next
slab page out and gets its content returned over the fabric (an
empirical run on a default nvmet-tcp loopback target leaked 81
canonical kernel pointers in one Get Log Page response). Pointing the
offset at unmapped kernel memory faults the in-kernel memcpy and
crashes (or panics, on panic_on_oops=1) the target host instead.
The attacker-controlled source-side offset pattern
"nvmet_copy_to_sgl(req, 0, buffer + ATTACKER_OFFSET, ...)" is unique
to nvmet_execute_disc_get_log_page in the entire nvmet codebase: every
other Get Log Page handler in admin-cmd.c either ignores lpo (and
silently starts every response at offset 0) or tracks a local
destination offset with a fixed source pointer.
Validate the host-supplied offset against the log page size, cap the
copy length to what is actually available, and zero-fill any remainder
of the host transfer buffer. The zero-fill matches the existing
short-response pattern in nvmet_execute_get_log_changed_ns()
(admin-cmd.c) and prevents leaking transport SGL contents when the
host asks for more bytes than the log page contains.
CVSS Score
9.1
EPSS Score
0.007
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
crypto: qat - protect service table iterations with service_lock
The service_table list is protected by service_lock when entries are
added or removed (in adf_service_add() and adf_service_remove()), but
several functions iterate over the list without holding this lock.
A concurrent adf_service_register() or adf_service_unregister() call
could modify the list during traversal, leading to list corruption or
a use-after-free.
Fix this by holding service_lock across all list_for_each_entry()
iterations of service_table in adf_dev_init(), adf_dev_start(),
adf_dev_stop(), adf_dev_shutdown(), adf_dev_restarting_notify(),
adf_dev_restarted_notify(), and adf_error_notifier().
The lock ordering is safe: callers of the static helpers (adf_dev_up()
and adf_dev_down()) acquire state_lock before service_lock, and no
event_hld callback or service_lock holder ever acquires state_lock in
the reverse order.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-25