Linux: >> Linux Kernel >> 6.1.156 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86/mmu: Check write tracking in all address spaces
kvm_gfn_is_write_tracked() checks only the supplied memslot, but page
tracking is per-address-space and shadow pages are shared across all
address spaces. With SMM, a GFN can therefore be write-tracked in one
address space and appear untracked through the other.
Check the supplied slot first, then the slot for the other address space.
This ensures all callers honor write tracking regardless of the active
address space. In particular, it prevents mmu_try_to_unsync_pages() from
marking an upper-level shadow page unsync and eventually triggering the
BUG in pte_list_remove().
[invert direction of the conditional. - Paolo]
CVSS Score
5.5
EPSS Score
0.001
Published
2026-09-29
In the Linux kernel, the following vulnerability has been resolved:
staging: rtl8723bs: fix mismatched free of HalData in rtw_sdio_if1_init()
padapter->HalData is allocated via vzalloc(), but incorrectly freed
using kfree() in the rtw_sdio_if1_init() error path. Using kfree() to
release this vmalloc-backed buffer can lead to memory corruption.
Use rtw_hal_data_deinit() to pair the free correctly and free
HalData with vfree().
The bug was first flagged by an experimental static analysis tool we
are developing for kernel memory-management bugs. Manual inspection
confirms that the issue is still present in current mainline.
An x86_64 allyesconfig build showed no new warnings. As we do not have
suitable RTL8723BS SDIO hardware to test with, no runtime testing was
able to be performed.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-09-25
In the Linux kernel, the following vulnerability has been resolved:
nvdimm: pmem: keep PREFLUSH before data writes
pmem_submit_bio() records a REQ_PREFLUSH error, but continues to copy the
bio data and can later overwrite the error with a successful REQ_FUA flush.
That lets data writes run after a failed preflush and can complete the bio
successfully despite the failed ordering barrier.
Run the REQ_PREFLUSH flush synchronously before touching the bio data and
complete the bio with the flush error if it fails. Keep asynchronous flush
chaining for REQ_FUA. At that point, data copy has completed and the parent
bio can wait for the chained flush bio.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-09-25
In the Linux kernel, the following vulnerability has been resolved:
smb/server: fix tree connection leak in smb2_tree_connect()
See the procedure below:
smb2_tree_connect
ksmbd_tree_conn_connect
xa_store(&sess->tree_conns, tree_conn->id, tree_conn)
ksmbd_counter_inc(KSMBD_COUNTER_TREE_CONNS)
ksmbd_share_tree_conn_inc(sc)
ksmbd_iov_pin_rsp // fail
status.ret = KSMBD_TREE_CONN_STATUS_NOMEM
// do not disconnect tree_conn
Disconnect the new tree connection if ksmbd_iov_pin_rsp() fails.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-09-25
In the Linux kernel, the following vulnerability has been resolved:
RDMA/srpt: Fix srpt_alloc_rw_ctxs() unwind counters
When srpt_alloc_rw_ctxs() fails partway through a multi-buffer indirect
descriptor, the unwind path destroys RDMA contexts but leaves stale
n_rw_ctx and n_rdma values (and a dangling rw_ctxs pointer). Later
sq_wr_avail accounting in srpt_queue_response() or srpt_write_pending()
can then subtract the wrong number of send queue credits.
Reset the counters and clear rw_ctxs after freeing the heap
allocation before returning an error.
CVSS Score
9.8
EPSS Score
0.004
Published
2026-09-25
In the Linux kernel, the following vulnerability has been resolved:
staging: rtl8723bs: fix xmit_frame/xmit_buf leaks on mgnt-frame error paths
issue_beacon(), issue_probersp() and issue_asocrsp() obtain a management
xmit_frame together with its xmit_buf from the driver's fixed-size
management-TX pools via alloc_mgtxmitframe(). On the normal path the frame
is handed to dump_mgntframe(), which transfers ownership and eventually
returns both objects to their pools (the frame and, for beacons, the buf
in rtl8723bs_mgnt_xmit(); other bufs via the pending-xmitbuf/TX-completion
path).
Several error/edge paths return early after a successful
alloc_mgtxmitframe() but before dump_mgntframe(), so ownership is never
transferred and neither object is freed:
- issue_beacon(): beacon larger than 512 bytes
- issue_probersp(): cur_network->ie_length > MAX_IE_SZ
- issue_probersp(): kzalloc() of the SSID scratch buffer fails
- issue_asocrsp(): pkt_type is neither ASSOCRSP nor REASSOCRSP
Because alloc_mgtxmitframe() removes the frame and buf from their free
lists (list_del_init) without placing them on any pending list, an
orphaned pair is on no list and referenced by nobody, so it is only
reclaimed at driver teardown. Repeated hits progressively exhaust the
management-TX pools until alloc_mgtxmitframe() returns NULL and the
interface can no longer send beacons or probe/assoc responses.
Free the frame and buffer on these paths, matching the existing correct
error handling in issue_assocreq().
CVSS Score
5.5
EPSS Score
0.001
Published
2026-09-25
In the Linux kernel, the following vulnerability has been resolved:
drm/msm: Recover HW before retire hung submit
During recovery, it is not safe to retire the hung submit before we
recover the GPU. Retiring the submit triggers BO free and that can
result in GPU pagefaults since the GPU may be actively accessing those
BOs.
To fix this, retire the submits after gpu recovery is complete in
recover_worker().
Patchwork: https://patchwork.freedesktop.org/patch/730655/
CVSS Score
5.5
EPSS Score
0.001
Published
2026-09-25
In the Linux kernel, the following vulnerability has been resolved:
wifi: iwlwifi: mei: pass correct argument to function
The first argument to iwl_mei_write_cyclic_buf() should be the cldev
but the q_head pointer is passed instead. Fix it.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-09-25
In the Linux kernel, the following vulnerability has been resolved:
6lowpan: fix NHC entry use-after-free on error path
lowpan_nhc_do_uncompression() looks up an NHC descriptor while holding
lowpan_nhc_lock. If the descriptor has no uncompress callback, the error
path drops the lock before printing nhc->name.
lowpan_nhc_del() removes descriptors under the same lock and then relies
on synchronize_net() before the owning module can be unloaded. That only
waits for net RX RCU readers. lowpan_header_decompress() is also exported
and can be reached from callers that are not necessarily covered by the net
core RX critical section, for example the Bluetooth 6LoWPAN L2CAP receive
path.
This leaves a race where one task drops lowpan_nhc_lock in the error path,
another task unregisters and frees the matching descriptor after
synchronize_net() returns, and the first task then dereferences nhc->name
for the warning.
With the post-unlock window widened, KASAN reports:
BUG: KASAN: slab-use-after-free in lowpan_nhc_do_uncompression+0x1f4/0x220
Read of size 8
lowpan_nhc_do_uncompression
lowpan_header_decompress
Fix this by printing the warning before dropping lowpan_nhc_lock, so the
descriptor name is read while unregister is still excluded. The malformed
packet is still rejected with -ENOTSUPP.
CVSS Score
7.1
EPSS Score
0.002
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
staging: rtl8723bs: fix OOB read in OnAssocRsp() IE loop
The IE parsing loop in OnAssocRsp() advances by (pIE->length + 2) each
iteration but only guards on i < pkt_len. When a malicious AP sends an
AssocResponse whose last IE has only one byte remaining in the frame
(the element_id byte lands at pkt_len-1), the loop reads pIE->length
from pframe[pkt_len], which is 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 pkt_len, silently 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 pkt_len.
CVSS Score
8.1
EPSS Score
0.004
Published
2026-07-25
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