| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
mm/rmap: fix missing barrier between anon_vma init and vma->anon_vma publish
On arm64 server, we find that a task trying to grab the anon_vma lock
triggers hungtask.
INFO: task main:2354726 blocked for more than 120 seconds.
Tainted: G E 5.10.0-0021.aarch64 #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:main state:D stack: 0 pid:2354726 ppid:2350673 flags:0x00000a01
Call trace:
__switch_to+0x7c/0xbc
__schedule+0x3b4/0x8a0
schedule+0x50/0xe0
rwsem_down_write_slowpath+0x3cc/0x6cc
down_write+0x60/0x260
__anon_vma_prepare+0x6c/0x210
do_anonymous_page+0x258/0x660
handle_pte_fault+0x188/0x214
__handle_mm_fault+0x1b0/0x380
handle_mm_fault+0xf4/0x284
do_page_fault+0x19c/0x494
do_translation_fault+0xcc/0xf8
do_mem_abort+0x48/0xac
el0_da+0x44/0x80
el0_sync_handler+0x88/0xb4
el0_sync+0x160/0x180
After analyzing the vmcore, we found the anon_vma->root->rwsem.count is
-1. There is another anon_vma whose anon_vma->root->rwsem.count is 1, the
anon_vma->root->rwsem.owner shows the lock is held, but the stack of the
task shows the task doesn't hold the anon_vma lock.
After adding more debugging info, we found __anon_vma_prepare() reuses
anon_vma and triggers the UAF of anon_vma->root due to missing memory
barrier, leading to locking and unlocking two different anon_vma->root,
thus leading to an anon_vma will never be unlocked, and another anon_vma
couldn't be locked anymore.
This race requires two adjacent VMAs that are not merged but are
anon_vma-compatible (e.g., they differ in VMA_ACCESS_FLAGS that can be
changed by mprotect()). Two threads fault on each VMA concurrently, both
calling __anon_vma_prepare() with only mmap_lock held for reading.
THREAD A THREAD B
__anon_vma_prepare __anon_vma_prepare
find_mergeable_anon_vma() -> NULL
anon_vma = anon_vma_alloc();
anon_vma->root = anon_vma;
// the two stores may be reordered
vma->anon_vma = anon_vma;
// finds A's anon_vma
anon_vma = find_mergeable_anon_vma(vma);
anon_vma_lock_write(anon_vma);
// may still see the old root
down_write(&anon_vma->root->rwsem);
anon_vma_unlock_write(anon_vma);
// see the new root, never unlock old
up_write(&anon_vma->root->rwsem);
thread A triggers page fault and calls __anon_vma_prepare() to prepare
anon_vma for the faulting vma. __anon_vma_prepare() allocates and
initializes a new anon_vma, and then publishes it to the vma with a plain
store. anon_vma_prepare() only requires the mmap_lock to be held for
reading, so two threads can fault on adjacent VMAs at the same time.
While thread A publishes a new anon_vma, thread B could find the anon_vma
via find_mergeable_anon_vma() and then locks anon_vma->root->rwsem.
The store to anon_vma->root in anon_vma_alloc() and the store to
vma->anon_vma can be reordered. The anon_vma_lock_write() and spin_lock()
only provide acquire semantics, which do not prevent prior stores from
being reordered after them. The release semantics of the corresponding
spin_unlock() and anon_vma_unlock_write() come too late, the store to
vma->anon_vma is already published before they take effect. As a result,
thread B can observe the following order:
vma->anon_vma = anon_vma;
anon_vma->root = anon_vma;
The anon_vma slab is SLAB_TYPESAFE_BY_RCU, so a newly allocated anon_vma
may reuse memory from a previously freed one. The constructor
(anon_vma_ctor) does not reset anon_vma->root, and __put_anon_vma()
doesn't clear it either, so the old root value persists until
anon_vma_alloc() overwrites it. If that store isn't v
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: mgmt: fix race in read_unconf_index_list()
read_unconf_index_list() counts unconfigured controllers before allocating
its response, then checks the device flags again while filling it.
hci_dev_list_lock stabilizes list membership, but it does not serialize the
per-device flags. During asynchronous controller setup, the worker can set
HCI_UNCONFIGURED and clear HCI_SETUP between the two passes. A controller
omitted from the allocation count can then become eligible for the fill
pass, causing an out-of-bounds write to rp->index[].
Allocate space for every device on hci_dev_list. Since list membership
cannot change while hci_dev_list_lock is held, the response remains large
enough regardless of flag transitions. The reported count and response
length still include only eligible unconfigured controllers. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix create context out-of-bounds reads
smb2_parse_contexts() validates the complete create-context area but
does not limit each record to its Next field before dispatching it. A
malformed chain can therefore expose bytes beyond the current context to
a handler. The QFid handler also used a full response-structure cast
although it only reads DiskFileId.
The SMB2/SMB3 lease parsers made the same layout assumption: they read
LeaseState and LeaseFlags at canonical offsets rather than at
DataOffset. A valid non-canonical DataOffset could therefore yield
unrelated in-bounds data, while a short DataLength was still accepted.
Limit each context to its Next value, reject offsets before the context
header, and reject malformed chains. Bound the name range by the current
context and do not dispatch a known handler when DataLength is zero. Read
the QFid DiskFileId only when the context data covers that field. Parse the
lease context from DataOffset and require DataLength to match the v1 or v2
lease_context size used by ksmbd. A size mismatch skips lease parsing
without failing the open. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: use finish_no_open() for non-regular inodes
An O_CREAT open can find an existing symlink or another non-regular
inode. cifs_atomic_open() calls finish_open() on it and attaches a
cifsFileInfo. Symlink inodes have no CIFS release operation, so the
dentry reference held by cifsFileInfo is leaked. FMODE_OPENED also
prevents the VFS from following the symlink.
Track whether cifs_do_create() returned an open server handle. For
non-regular inodes, close the handle if present, remove the pending
open, and call finish_no_open() so the VFS can continue the lookup.
Do not set FMODE_CREATED unless a regular file was opened. For
O_NOFOLLOW with __O_REGULAR, return -ELOOP before the VFS's
-EFTYPE check.
Defer closing a legacy POSIX handle on a non-regular inode until
after inode lookup. This avoids closing it again if lookup fails. |
| In the Linux kernel, the following vulnerability has been resolved:
xfs: fix cursor and pointer handling when recovering iunlink buckets
LOLLM pointed out a bug in xlog_recover_iunlink_bucket:
1. We don't null out prev_ip after releasing it, which can lead to UAF
problems if the inodegc flush call in the loop fails.
at which point I noticed even more bugs:
2. If the inodegc flush inside the loop fails, we also leak @ip.
3. We set prev_agino to agino having already advanced agino, which
results in inodes with i_prev_unlinked set to itself.
4. If we exit the bottom of the loop with prev_ip set, then prev_ip
aliases ip and we also set its i_prev_unlinked to itself.
Bugs 3 and 4 introduce loops into the unlinked list, though these loops
don't surface because we immediately flush each unlinked inode after
loading it.
Fix all of these issues. |
| In the Linux kernel, the following vulnerability has been resolved:
vlan: require the MAC header to be present in __vlan_insert_inner_tag()
__vlan_insert_inner_tag() only guarantees head room via skb_cow_head(),
never that mac_len bytes of MAC header are present. Its ETH_HLEN
wrappers - __vlan_insert_tag() under skb_vlan_push(), and
vlan_insert_tag() under validate_xmit_vlan() on the generic transmit
path - therefore rewrite the first 16 bytes at skb->data: a 12-byte
memmove plus two 2-byte stores at +12 and +14. No caller supplies the
bound, while the pop helpers use skb_ensure_writable()/pskb_may_pull().
An IFF_TUN device has hard_header_len == 0, so packet_snd() accepts a
one-byte AF_PACKET/SOCK_RAW frame. The first vlan push only sets a
hwaccel tag; the next - clsact "action vlan push" or
bpf_skb_vlan_push() - enters the helper with skb->len still 1. The
head comes from skbuff_small_head without __GFP_ZERO, so each push
drags bytes from beyond skb->tail into the frame. After three the
one-byte send leaves as 13 bytes carrying 11 bytes of uninitialised
slab:
0000: 5a b3 62 12 80 88 ff ff 00 b3 62 12 81
`------------------------------'
only 0x5a was sent; the rest is slab, here the top 56 bits of a
linear-map address
Require the MAC header the helper rewrites to be present, so such a
frame is dropped rather than transmitted. |
| In the Linux kernel, the following vulnerability has been resolved:
xen/netfront: drop RX packets with a short Ethernet header
handle_incoming_queue() pulls pull_to bytes into the head before
calling eth_type_trans(). pull_to is the length of the first RX slot,
capped at RX_COPY_THRESHOLD, and that length comes from the backend.
Nothing checks it against ETH_HLEN.
If the first slot is shorter than ETH_HLEN and more slots follow, the
head ends up shorter than an Ethernet header while skb->len is longer,
and eth_type_trans() BUG()s in __skb_pull(). If the whole packet is
shorter than ETH_HLEN, eth_type_trans() reads the header past the end
of the data instead.
Pull at least ETH_HLEN, and drop the packet if that fails, which also
drops packets too short to hold an Ethernet header. This also checks
the return value of the pull, which was ignored. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/hugetlb: preserve mremap address delta when skipping page tables
move_hugetlb_page_tables() optimizes mremap() by advancing to the last
entry in the page table when the source page table does not exist, either
initially or after unsharing a PMD table. The common loop increment then
steps to the first entry in the next page table.
However, the code advances both the source and destination addresses to
the last entries in their respective page tables, which is wrong. The
destination address must be advanced only by the same amount as the source
address.
If the source and destination offsets within their page tables differ, the
destination address can be advanced too far, causing follow-up issues.
Fix this by advancing the destination address by the source advance
distance.
With a reproducer, we were able to trigger a kernel panic on x86-64. With
this fix in place, we can no longer reproduce the issue. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: Clamp implicit feedback packet count to URB capacity
data_ep_set_params() allocates each data URB for exactly u->packets
isochronous frames, so urb->iso_frame_desc[] has u->packets slots and
ctx->packets is the driver's only record of that limit. For an implicit
feedback sink, snd_usb_queue_pending_output_urbs() overwrites it with the
sync source's packet count, which is calculated independently from the
capture endpoint's parameters. When that count is larger,
prepare_playback_urb() and prepare_silent_urb() can write
iso_frame_desc[] past the allocation; their existing bounds limit payload
bytes, not the descriptor index.
The reproducer uses a high-speed UAC2 device declaring bInterval 1 for
implicit feedback capture (8 packets) and bInterval 4 for playback
(1 packet). On the first capture completion after the stream starts, it
accesses seven descriptors spanning 112 bytes beyond the one-packet URB:
BUG: KASAN: slab-out-of-bounds in prepare_playback_urb (sound/usb/pcm.c:1560)
Write of size 4 at addr ffff88801e696ad0 by task vhci_rx/178
prepare_playback_urb (sound/usb/pcm.c:1560)
prepare_outbound_urb (sound/usb/endpoint.c:340)
snd_usb_queue_pending_output_urbs (sound/usb/endpoint.c:501)
snd_complete_urb (sound/usb/endpoint.c:1834)
__usb_hcd_giveback_urb (drivers/usb/core/hcd.c:1657)
usb_hcd_giveback_urb (drivers/usb/core/hcd.c:1741)
vhci_rx_loop (drivers/usb/usbip/vhci_rx.c:107)
kthread (kernel/kthread.c:436)
The buggy address belongs to the object at ffff88801e696a00
which belongs to the cache kmalloc-256 of size 256
The buggy address is located 0 bytes to the right of
allocated 208-byte region [ffff88801e696a00, ffff88801e696ad0)
Record the allocated packet count per endpoint and clamp both the adopted
count and the packet-size copy to it. Fold the Format Type II delimiter
into urb_packs before the allocation loop so the recorded limit matches
every URB. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: virtio: reset device before deleting virtqueues
virtsnd_remove() and virtsnd_freeze() delete the virtqueues before
resetting the device. del_vqs() frees the vring backing, but does not
provide a generic device quiesce operation. In particular, modern
virtio-pci keeps enabled queues active until the device is reset.
Reset the device before deleting the virtqueues so it can no longer
access the vring memory when that memory is released. This also covers
probe failures after DRIVER_OK, which unwind through virtsnd_remove(). |
| In the Linux kernel, the following vulnerability has been resolved:
exec: Cleanup POSIX timers right after de_thread()
A per-thread CPU timer holds a reference to the PID of the thread it is
attached to and, while it is armed, its node is queued in that thread's
posix_cputimers. The task is looked up by that PID.
When a non-leader thread exec()s, de_thread() changes which task owns
that PID. pid_task(timer->it.cpu.pid, PIDTYPE_PID) then returns NULL,
but the node is still queued on tsk, which is alive. timer_lock_sighand()
takes a failed lookup to mean that the node is already dequeued, so it
has nothing to undo.
begin_new_exec() calls posix_cpu_timers_exit(me) right after
exec_task_namespaces() and that removes the leftover node, so the state
normally stays invisible. But bprm->point_of_no_return is set before
de_thread(), so if unshare_files(), set_mm_exe_file(), exec_mmap() or
exec_task_namespaces() fails, the task dies before it gets there.
exit_itimers() then frees the k_itimer while its node is still queued,
and reaping tsk later erases that freed node from the rbtree.
In short:
the non-leader thread B the parent
timer_create(CLOCK_THREAD_CPUTIME_ID)
timer_settime()
arm_timer() // the node is queued on B
execve()
de_thread(B)
exchange_tids(B, leader) // B's PID now belongs to the leader
release_task(leader)
__exit_signal(leader)
posix_cpu_timers_exit(leader) // cleans leader's queue, not B's
__unhash_process(leader) // that PID has no task anymore
exec_mmap()
mmap_read_lock_killable(old_mm)
kill(B, SIGKILL)
// -EINTR
get_signal()
do_exit()
exit_itimers()
posix_timer_delete()
posix_cpu_timer_del()
posix_timer_unhash_and_free() // freed while still queued
wait4()
release_task(B)
posix_cpu_timers_exit(B)
cleanup_timerqueue()
timerqueue_del() // use-after-free
Move the POSIX timer cleanup right after de_thread() before any of the
later failure conditions brings the task into do_exit().
[ tglx: Move the cleanup right after de_thread() ] |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: take commit root semaphore when iterating in mark_block_group_to_copy()
mark_block_group_to_copy() iterates over the commit root with
skip_locking=true. A concurrent transaction commit can swap and free
the commit root during iteration, causing use-after-free when
accessing extent buffers.
Fix it by using path->need_commit_sem to protect the commit root search. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix use-after-free of iface in cifs_try_adding_channels()
cifs_try_adding_channels() iterates ses->iface_list with
list_for_each_entry_safe_from(), which captures the next entry
(niface) under iface_lock. The loop body then drops iface_lock for
the whole duration of cifs_ses_add_channel().
A concurrent interface refresh (SMB3_request_interfaces() ->
parse_server_interfaces()) marks all ifaces inactive and removes and
frees any that are not re-advertised via list_del() + kref_put(),
where release_iface() is a bare kfree(). Since niface typically has
no channel holding a reference, the list reference is its last and it
can be freed inside the unlocked window. On continue, the iterator
advance step then dereferences niface->iface_head.next, and the loop
body reads iface->rdma_capable/is_active, both on freed memory.
Fix this by never keeping an unreferenced list pointer across the
unlocked window. Each channel attempt now re-scans the list from the
head under iface_lock, takes a kref on the selected candidate, and
passes only that referenced candidate to cifs_ses_add_channel().
weight_fulfilled still tracks selection progress, so restarting the
scan preserves the original weighted distribution and the
weight_fulfilled-before-kref_put ordering on the failure path.
Add a per-pass attempts cap so a flapping interface refresh cannot
keep the inner loop spinning within a single tries increment. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix next_buffer UAF and NextCommand bounds in compound PDUs
Fix several related bounds checking and pointer lifecycle issues in
receive_encrypted_standard()'s handling of compound encrypted frames:
- Clear next_buffer after assigning it to server->bigbuf. A stale
next_buffer pointer can lead to a use-after-free on subsequent
error paths.
- Update pdu_length to the decrypted plaintext size (buf_size). Using
the pre-decryption length allows NextCommand to point into stale
ciphertext residue.
- Reject next_cmd values smaller than MID_HEADER_SIZE(server).
- Fix an integer overflow in the upper bound check by verifying
pdu_length - next_cmd < MID_HEADER_SIZE(server), ensuring the
trailing slice is large enough for a header. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix potential OOB read in smb3_enum_snapshots()
If snapshot_array_size is smaller than GMT_TOKEN_SIZE,
smb3_enum_snapshots() sets ret_data_len to
sizeof(struct smb_snapshot_array) without verifying the actual length
of the server's reply.
Because SMB2_ioctl() places no lower bound on the server-supplied
OutputCount and allocates retbuf to exactly that length, a short reply
results in ret_data_len exceeding the size of retbuf. The subsequent
copy_to_user() then reads past the end of retbuf, leaking adjacent slab
memory to userspace. The subsequent clamp check is ineffective as it
only reduces ret_data_len.
Fix this by rejecting replies shorter than
sizeof(struct smb_snapshot_array) with -EIO. Note that the bound is set
to the 12-byte struct size rather than the 16-byte
MIN_SNAPSHOT_ARRAY_SIZE defined in MS-SMB2 3.3.5.15.1, because 12 bytes
is exactly what copy_to_user() attempts to read. |
| In the Linux kernel, the following vulnerability has been resolved:
tracing: Set the trace clock before registering the histogram trigger
hist_register_trigger() puts the trigger on the global named_triggers
list in cmd_ops->init(), and only then sets the trace clock:
if (data->cmd_ops->init) {
ret = data->cmd_ops->init(data);
if (ret < 0)
goto out;
}
if (hist_data->enable_timestamps) {
ret = tracing_set_clock(file->tr, hist_data->attrs->clock);
if (ret) {
hist_err(tr, HIST_ERR_SET_CLOCK_FAIL, errpos(clock));
goto out;
}
The clock string is not checked anywhere before that call, so a named
trigger using common_timestamp with an unknown clock fails after it has
already become findable. event_hist_trigger_parse() then frees it
without taking it off the list, and the next lookup by name reads the
freed object:
~# cd /sys/kernel/tracing/events/sched/sched_switch
~# echo 'hist:name=foo:keys=common_pid:ts=common_timestamp:clock=bogus' > trigger
bash: echo: write error: Invalid argument
~# echo 'hist:name=foo:keys=common_pid' > trigger
BUG: KASAN: slab-use-after-free in find_named_trigger+0xac/0xc0
Read of size 8 at addr ffff88800915d760 by task init/1
find_named_trigger+0xac/0xc0
hist_register_trigger+0xc1/0x900
event_hist_trigger_parse+0x3146/0x6af0
event_trigger_write+0xce/0x160
Freed by task 63:
kfree+0x154/0x420
trigger_kthread_fn+0xfd/0x160
Set the clock before the trigger is registered, so that nothing which
can fail runs after it is published, the way commit 6f86bdeab633
("tracing: Fix bad hist from corrupting named_triggers list") moved the
registration below the rest of the setup.
tracing_set_filter_buffering() is reference counted, so the init failure
path has to drop the reference that the clock block now takes first. |
| In the Linux kernel, the following vulnerability has been resolved:
genetlink: pin family module during policy dump
The generic netlink controller's policy dump keeps pointers to the target
family's operation and policy tables in its callback state. A dump may be
split across multiple skbs and remain pending after the initial request.
Netlink pins the module which owns the dump callback, but in this case
that is the controller's owner rather than the target family's owner. The
target family can consequently be unregistered and its module unloaded
while a policy dump is pending. Advancing the dump then dereferences
policy memory from the unloaded module.
Take a reference to the target family's module when the dump starts.
Drop it from the error and done paths. This matches the lifetime for which
the dump context retains the family and policy pointers. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: cttimeout: prevent UAF during module unload
nf_ct_set_timeout() protects the timeout hook dereference and policy lookup
with rcu_read_lock(). cttimeout_exit(), however, unregisters the per-net
operations before it clears the hook.
This allows the following interleaving:
CPU 0 CPU 1
cttimeout_exit() nf_ct_set_timeout()
unregister_pernet_subsys() rcu_read_lock()
kfree(pernet) h = nf_ct_timeout_hook
h->timeout_find_get()
nfct_timeout_pernet()
The hook still points to ctnl_timeout_find_get() when CPU 1 looks up the
already freed per-net timeout list. KASAN reported:
BUG: KASAN: slab-use-after-free in ctnl_timeout_find_get
Read of size 8 by task poc/90
Call Trace:
ctnl_timeout_find_get+0x271/0x2a0 [nfnetlink_cttimeout]
nf_ct_set_timeout+0x7b/0x3c0
xt_ct_tg_check+0x724/0xb20
xt_check_target+0x234/0xa90
do_ipt_set_ctl+0x570/0x1270
Allocated by task 89:
__kmalloc_noprof+0x16e/0x460
ops_init+0x6d/0x420
register_pernet_operations+0x2f6/0x670
Freed by task 91:
kfree+0x131/0x390
ops_undo_list+0x3d4/0x730
unregister_pernet_operations+0x232/0x490
unregister_pernet_subsys+0x1c/0x30
cttimeout_exit+0x52/0x970 [nfnetlink_cttimeout]
Clear the hook and wait for existing readers before unregistering the
per-net operations. This blocks new policy lookups and ensures readers that
observed the hook finish before the per-net storage is freed. |
| In the Linux kernel, the following vulnerability has been resolved:
landlock: Fix use-after-free of the source's parent directory
current_check_refer_path() reads old_dentry->d_parent without holding a
reference nor a lock on it, and then dereferences it in
collect_domain_accesses() and in the audit record.
A reference on a child does not pin its parent: __d_move() reassigns
dentry->d_parent and drops the reference the child held on its former
parent. hook_path_rename() is not affected because the rename path
calls lock_rename() before the hook, so the source cannot be reparented
under it. hook_path_link() has no such protection: filename_linkat()
holds a reference on the source dentry but neither locks nor references
its parent, so a concurrent rename(2) can reparent the source while
security_path_link() runs, and the former parent can then be removed and
freed while the hook walks it.
A process can trigger this after entering a Landlock domain that handles
at least one filesystem access right. The process can then race a
linkat(2) loop against rename(2) and rmdir(2):
BUG: KASAN: slab-use-after-free in collect_domain_accesses+0x278/0x290
Read of size 4 at addr ffff888160bd53f4 by task llrepro2/549
collect_domain_accesses+0x278/0x290
current_check_refer_path+0x952/0x1120
security_path_link+0x1be/0x320
filename_linkat+0x342/0x6d0
__x64_sys_linkat+0xfa/0x150
Freed by task 562:
kmem_cache_free+0x139/0x4c0
i_callback+0x4b/0x80
rcu_core+0x7dc/0x10a0
Take a reference on the dentry selected as the source parent, using
dget() for the common-mount-root case and dget_parent() otherwise.
Release it after the hierarchy walk and synchronous audit logging.
[mic: Clarify the caller, reachability, and reference handling] |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: reject userspace cifs.idmap descriptions
cifs.idmap key descriptions carry authority-bearing fields (owner and
group SIDs and uid/gid values in "os:"/"gs:"/"oi:"/"gi:" form) that the
cifs.idmap upcall helper treats as kernel-originating inputs. Unlike
its sibling cifs.spnego, the cifs.idmap key type has no vet_description
hook, so userspace can create keys of this type through
request_key(2)/add_key(2) and supply those fields without CIFS origin.
A request_key(2) call with a non-NULL callout then drives a root
usermodehelper upcall (/sbin/request-key -> cifs.idmap) that consumes
the unvetted description in root context.
Only accept cifs.idmap descriptions while CIFS is using its private
root_cred to request the key. id_to_sid()/sid_to_id() already run
under override_creds(root_cred), so the kernel-originated path is
unaffected.
This mirrors commit 3da1fdf4efbc ("smb: client: reject userspace
cifs.spnego descriptions"), which applied the same restriction to
cifs.spnego. |