Linux: >> Linux Kernel >> 6.18.36 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix use-after-free of a deferred file_lock on SMB2_CLOSE then SMB2_CANCEL
Commit f580d27e8928 ("ksmbd: fix use-after-free of a deferred file_lock on
double SMB2_CANCEL") made smb2_cancel() skip a work whose state is
KSMBD_WORK_CANCELLED, so its cancel_fn cannot be fired a second time. But
KSMBD_WORK has three states (ACTIVE, CANCELLED, CLOSED), and the same
freeing producer path is reached for CLOSED too:
SMB2_CLOSE on the locking handle -> set_close_state_blocked_works() sets
the deferred work's state to KSMBD_WORK_CLOSED and wakes the smb2_lock()
worker. The worker takes the non-ACTIVE early-exit, locks_free_lock()s
the file_lock and, because the state is not KSMBD_WORK_CANCELLED, takes
the STATUS_RANGE_NOT_LOCKED branch with "goto out2" -- which, like the
cancelled branch, skips release_async_work(). The work stays on
conn->async_requests with a live cancel_fn = smb2_remove_blocked_lock
pointing at the freed file_lock.
A subsequent SMB2_CANCEL for the same AsyncId then passes the
KSMBD_WORK_CANCELLED-only guard (its state is KSMBD_WORK_CLOSED), so
smb2_cancel() fires cancel_fn again over the freed file_lock -- the same
use-after-free fixed, via SMB2_CLOSE instead of a first SMB2_CANCEL:
BUG: KASAN: slab-use-after-free in __locks_delete_block
__locks_delete_block
locks_delete_block
ksmbd_vfs_posix_lock_unblock
smb2_remove_blocked_lock
smb2_cancel <- 2nd SMB2_CANCEL fires cancel_fn
handle_ksmbd_work
Allocated by ...: locks_alloc_lock <- smb2_lock
Freed by ...: locks_free_lock <- smb2_lock (non-ACTIVE early-exit)
... cache file_lock_cache of size 192
Reproduced on mainline 7.1-rc7 (which already contains f580d27e8928) with
KASAN by an authenticated SMB client; the double-SMB2_CANCEL control is
silent on that kernel, so the splat is attributable to the CLOSE trigger.
Only an ACTIVE deferred work may have its cancel_fn fired: both terminal
states (CANCELLED and CLOSED) reach the smb2_lock() early-exit that frees
the file_lock and skips release_async_work(). Guard on KSMBD_WORK_ACTIVE
so any non-active work is skipped.
CVSS Score
8.8
EPSS Score
0.006
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
crypto: qat - fix VF2PF work teardown race in adf_disable_sriov()
The VF2PF interrupt handler queues PF-side response work that stores a
raw pointer to per-VF state (struct adf_accel_vf_info). Currently,
adf_disable_sriov() destroys per-VF mutexes and frees vf_info without
stopping new VF2PF work or waiting for in-flight workers to complete. A
concurrently scheduled or already queued worker can then dereference
freed memory.
This manifests as a use-after-free when KASAN is enabled:
BUG: KASAN: null-ptr-deref in mutex_lock+0x76/0xe0
Write of size 8 at addr 0000000000000260 by task kworker/24:2/...
Workqueue: qat_pf2vf_resp_wq adf_iov_send_resp [intel_qat]
Call Trace:
kasan_report+0x119/0x140
mutex_lock+0x76/0xe0
adf_gen4_pfvf_send+0xd4/0x1f0 [intel_qat]
adf_recv_and_handle_vf2pf_msg+0x290/0x360 [intel_qat]
adf_iov_send_resp+0x8c/0xe0 [intel_qat]
process_one_work+0x6ac/0xfd0
worker_thread+0x4dd/0xd30
kthread+0x326/0x410
ret_from_fork+0x33b/0x670
Add a PF-local flag, vf2pf_disabled, that gates work queueing, worker
processing, and interrupt re-enabling during teardown. Set this flag
atomically with the hardware interrupt mask inside
adf_disable_all_vf2pf_interrupts(). After masking, synchronize the AE
cluster MSI-X interrupt and flush the PF response workqueue before
tearing down per-VF locks and state so all in-flight work completes
before vf_info is destroyed.
Introduce adf_enable_all_vf2pf_interrupts() to clear the flag and
unmask all VF2PF interrupts under the same lock when SR-IOV is
re-enabled. This ensures the software flag and hardware state transition
atomically on both the enable and disable paths.
CVSS Score
8.8
EPSS Score
0.002
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
crypto: krb5 - filter out async aead implementations at alloc
krb5_aead_encrypt(), krb5_aead_decrypt() in rfc3961_simplified.c and
rfc8009_encrypt(), rfc8009_decrypt() in rfc8009_aes2.c set a NULL
completion callback and treat any negative return from
crypto_aead_{encrypt,decrypt}() as terminal, falling through to
kfree_sensitive(buffer). When the encrypt_name resolves to an
async AEAD instance the request returns -EINPROGRESS, the buffer
is freed while the backend's worker still holds a pointer, and the
worker dereferences the freed slab on completion.
KASAN report under UML+SLUB with a synthetic async aead backend
bound to krb5->encrypt_name:
BUG: KASAN: slab-use-after-free in t5_stub_complete+0x7d/0xc7
The helpers were written synchronously, so filter the async
instances out at allocation time instead of plumbing
crypto_wait_req() through every call site.
Reachable via net/rxrpc/rxgk.c, fs/afs/cm_security.c and
net/ceph/crypto.c on systems with an async AEAD provider bound to
the krb5 enctype name.
CVSS Score
9.8
EPSS Score
0.006
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
staging: rtl8723bs: fix OOB write in HT_caps_handler()
HT_caps_handler() iterates pIE->length bytes and writes into
HT_caps.u.HT_cap[], which is a fixed 26-byte array (sizeof struct
HT_caps_element). Because pIE->length is a raw u8 from an over-the-air
802.11 AssocResponse frame and is never validated, a malicious AP can
set it up to 255, causing up to 229 bytes of out-of-bounds writes into
adjacent fields of struct mlme_ext_info.
Truncate the iteration count to the size of HT_caps.u.HT_cap using
umin() so that data from a longer-than-expected IE is silently ignored
rather than written out of bounds, preserving interoperability with APs
that pad the element. An early return on oversized IEs was considered
but rejected: it would bypass the pmlmeinfo->HT_caps_enable = 1
assignment that precedes the loop, silently disabling HT mode for APs
that append extra bytes to the HT Capabilities IE.
CVSS Score
8.1
EPSS Score
0.004
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
staging: rtl8723bs: fix OOB reads in rtw_get_sec_ie(), rtw_get_wapi_ie(), and rtw_get_wps_attr()
Three IE/attribute parsing functions have missing bounds checks.
rtw_get_sec_ie() and rtw_get_wapi_ie() iterate over a raw IE buffer
without verifying that the header bytes (tag + length) are within the
remaining buffer before reading them. Additionally, rtw_get_sec_ie()
compares the 4-byte WPA OUI at cnt+2 without checking that at least
6 bytes remain, and rtw_get_wapi_ie() compares a 4-byte WAPI OUI at
cnt+6 without checking that at least 10 bytes remain.
rtw_get_wps_attr() reads wps_ie[0] and wps_ie+2 unconditionally at
entry, before verifying that wps_ielen is large enough to contain
the 6-byte WPS IE header (element_id + length + 4-byte OUI). Inside
the attribute loop, get_unaligned_be16() is called on attr_ptr and
attr_ptr+2 without checking that 4 bytes remain in the buffer.
Add a cnt+2 bounds check before each loop body in rtw_get_sec_ie()
and rtw_get_wapi_ie(), guard each multi-byte comparison with a minimum
IE length requirement, add a wps_ielen < 6 early return in
rtw_get_wps_attr(), and add a 4-byte bounds check in its inner loop.
CVSS Score
8.8
EPSS Score
0.004
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
staging: rtl8723bs: fix OOB reads in IE loops in issue_assocreq() and join_cmd_hdl()
Two IE parsing loops are missing the header bounds checks before they
dereference pIE->length:
- issue_assocreq() walks pmlmeinfo->network.ies to build the
association request. If the stored IE data ends with only an
element_id byte and no length byte, pIE->length is read one byte
past the end of the buffer.
- join_cmd_hdl() walks pnetwork->ies during station join and has
the same problem under the same conditions.
Both buffers are filled from AP beacon and probe-response frames, so a
malicious AP that sends a truncated final IE can trigger the issue.
Apply the two-guard pattern established in update_beacon_info():
1. Break if fewer than sizeof(*pIE) bytes remain.
2. Break if the IE's declared data extends past the buffer end.
CVSS Score
8.1
EPSS Score
0.004
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
staging: rtl8723bs: fix OOB read in update_beacon_info() IE loop
The IE parsing loop in update_beacon_info() advances by
(pIE->length + 2) each iteration but only guards on i < len.
When a malicious AP sends a Beacon whose last IE has only one byte
remaining in the frame (the element_id byte lands at len-1), the loop
reads pIE->length from one byte past the allocated receive buffer.
Additionally, even when the header bytes are in bounds, pIE->length
itself can extend the data window beyond len, passing a truncated IE
to the handler functions.
Add two guards at the top of the loop body:
1. Break if fewer than sizeof(*pIE) bytes remain (can't read header).
2. Break if the IE's declared data extends past len.
Also replace i += (pIE->length + 2) with i += sizeof(*pIE) + pIE->length
for consistency with the sizeof(*pIE) guards added above.
CVSS Score
8.1
EPSS Score
0.004
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
gpio: eic-sprd: use raw_spinlock_t in the irq startup path
sprd_eic_irq_unmask() enables the GPIO IRQ and then updates controller
state through sprd_eic_update(), which takes sprd_eic->lock with
spin_lock_irqsave(). The callback can be reached from irq_startup()
while setting up a requested IRQ. That path is not sleepable, but on
PREEMPT_RT a regular spinlock_t becomes a sleeping lock.
This issue was found by our static analysis tool and then manually
reviewed against the current tree.
The grounded PoC kept the request_threaded_irq() -> __setup_irq() ->
irq_startup() -> sprd_eic_irq_unmask() -> sprd_eic_update() carrier and
used the original spin_lock_irqsave(&sprd_eic->lock) edge. Lockdep
BUG: sleeping function called from invalid context
hardirqs last disabled at ... __setup_irq.constprop.0 ... [vuln_msv]
sprd_rt_spin_lock_irqsave+0x1c/0x30 [vuln_msv]
sprd_eic_update.constprop.0+0x48/0x90 [vuln_msv]
sprd_eic_irq_unmask.constprop.0+0x35/0x50 [vuln_msv]
__setup_irq.constprop.0+0xd/0x30 [vuln_msv]
Convert the Spreadtrum EIC controller lock to raw_spinlock_t. The
locked section only serializes MMIO register updates and does not contain
sleepable operations, so keeping it non-sleeping is appropriate for the
irqchip callbacks.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
NTB: epf: Avoid calling pci_irq_vector() from hardirq context
ntb_epf_vec_isr() calls pci_irq_vector() in hardirq context to derive
the vector number. pci_irq_vector() calls msi_get_virq() that takes a
mutex and can therefore trigger "scheduling while atomic" splats:
BUG: scheduling while atomic: kworker/u33:0/55/0x00010001
...
Call trace:
...
schedule+0x38/0x110
schedule_preempt_disabled+0x28/0x50
__mutex_lock.constprop.0+0x848/0x908
__mutex_lock_slowpath+0x18/0x30
mutex_lock+0x4c/0x60
msi_domain_get_virq+0xe8/0x138
pci_irq_vector+0x2c/0x60
ntb_epf_vec_isr+0x28/0x120 [ntb_hw_epf]
__handle_irq_event_percpu+0x70/0x3a8
handle_irq_event+0x48/0x100
handle_edge_irq+0x100/0x1c8
...
Cache the Linux IRQ number for vector 0 when vectors are allocated and
use it as a base in the ISR. Running the ISR in a threaded IRQ handler
would also avoid the problem, but that would be unnecessary here.
CVSS Score
7.5
EPSS Score
0.007
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: validate Dirty Page Table capacity in log_replay copy_lcns
In the analysis pass of $LogFile journal replay, log_replay() copies
LCNs from each action log record into an existing Dirty Page Table
(DPT) entry without bounding the destination index. A crafted NTFS
image with DPT entry lcns_follow=1 and an action log record with
lcns_follow=2 produces a kernel slab out-of-bounds write at mount
time:
BUG: KASAN: slab-out-of-bounds in log_replay+0x654c/0xdb60
Write of size 8 at addr ffff8880095e1040 by task mount
Two attacker-controlled fields can drive j+i past the allocated
page_lcns[] array:
1. dp->lcns_follow (capacity) can be smaller than lrh->lcns_follow.
2. lrh->target_vcn may be smaller than dp->vcn, making the u64
subtraction wrap to a huge size_t.
Validate target VCN delta and per-record LCN count against the
DPT entry capacity, bail via the existing out: cleanup label with
-EINVAL.
This mirrors the bounds-check pattern added in commit b2bc7c44ed17
("fs/ntfs3: Fix slab-out-of-bounds read in DeleteIndexEntryRoot")
and commit 0ca0485e4b2e ("fs/ntfs3: validate rec->used in
journal-replay file record check").
CVSS Score
7.8
EPSS Score
0.002
Published
2026-07-25