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🚨 CVE-2026-53164
In the Linux kernel, the following vulnerability has been resolved:

iommu/dma: Do not try to iommu_map a 0 length region in swiotlb

iommu_dma_iova_link_swiotlb() processes a mapping that is unaligned in three
parts, the head, middle and trailer. If the middle is empty because there
are no aligned pages it will call down to iommu_map() with a 0 size
which the iommupt implementation will fail as illegal.

It then tries to do an error unwind and starts from the wrong spot
corrupting the mapping so the eventual destruction triggers a WARN_ON.

Check for 0 length and avoid mapping and use offset not 0 as the starting
point to unlink.

This is frequently triggered by using some kinds of thunderbolt NVMe
drives that trigger forced SWIOTLB for unaligned memory. NVMe seems to
pass in oddly aligned buffers for the passthrough commands from smartctl
that hit this condition.

🎖@cveNotify
🚨 CVE-2026-53165
In the Linux kernel, the following vulnerability has been resolved:

iomap: avoid potential null folio->mapping deref during error reporting

When a buffered read fails, iomap_finish_folio_read() reports the error
with fserror_report_io(folio->mapping->host, ...). This is called after
ifs->read_bytes_pending has been decremented by the bytes attempted to
be read.

For a folio split across multiple read completions, the folio is only
guaranteed to stay locked while read_bytes_pending > 0. Once
iomap_finish_folio_read() decrements read_bytes_pending, another
in-flight read can complete and end the read on the folio, which unlocks
it. This allows truncate logic to run and detach the folio (set
folio->mapping to NULL). The error reporting path then can dereference a
NULL folio->mapping. As reported by Sam Sun, this is the race that can
occur:

CPU0: failed completion CPU1: final completion CPU2: truncate
----------------------- ---------------------- --------------
read_bytes_pending -= len
finished = false
/* preempted before
fserror_report_io() */
read_bytes_pending -= len
finished = true
folio_end_read()
truncate clears
folio->mapping
fserror_report_io(
folio->mapping->host, ...)
^ NULL deref

Fix this by reporting the error first before decrementing
ifs->read_bytes_pending.

🎖@cveNotify
🚨 CVE-2026-53167
In the Linux kernel, the following vulnerability has been resolved:

fuse: limit FUSE_NOTIFY_RETRIEVE to uptodate folios

FUSE_NOTIFY_RETRIEVE must be limited to uptodate folios; !uptodate folios
can contain uninitialized data.
Since FUSE_NOTIFY_RETRIEVE is intended to only return data that is already
in the page cache and not wait for data from the FUSE daemon, treat
!uptodate folios as if they weren't present.

This only has security impact on systems that don't enable automatic
zero-initialization of all page allocations via
CONFIG_INIT_ON_ALLOC_DEFAULT_ON or init_on_alloc=1.

🎖@cveNotify
🚨 CVE-2026-53168
In the Linux kernel, the following vulnerability has been resolved:

fuse: reject fuse_notify() pagecache ops on directories

The operations FUSE_NOTIFY_STORE and FUSE_NOTIFY_RETRIEVE allow the
FUSE daemon to actively write/read pagecache contents.

For directories with FOPEN_CACHE_DIR, the pagecache is used as
kernel-internal cache storage, and userspace is not supposed to have
direct access to this cache - in particular, fuse_parse_cache() will hit
WARN_ON() if the cache contains bogus data.

Reject FUSE_NOTIFY_STORE and FUSE_NOTIFY_RETRIEVE on anything other than
regular files with -EINVAL.

🎖@cveNotify
🚨 CVE-2026-53169
In the Linux kernel, the following vulnerability has been resolved:

accel/ethosu: reject NPU_OP_RESIZE commands from userspace

NPU_OP_RESIZE is a U85-only command that the driver does not yet
implement. The existing WARN_ON(1) placeholder fires unconditionally
whenever userspace submits this command via DRM_IOCTL_ETHOSU_GEM_CREATE,
causing unbounded kernel log spam.

If panic_on_warn is set the kernel panics, giving any unprivileged user
with access to the DRM device a trivial denial-of-service primitive.

Replace the WARN_ON(1) with an explicit -EINVAL return so the ioctl
rejects the command before it reaches hardware.

🎖@cveNotify
🚨 CVE-2026-53170
In the Linux kernel, the following vulnerability has been resolved:

accel/ethosu: reject DMA commands with uninitialized length

cmd_state_init() initializes the command state with memset(0xff),
leaving dma->len at U64_MAX to signal missing setup. The only setter
is NPU_SET_DMA0_LEN; if userspace omits this command and issues
NPU_OP_DMA_START, dma->len remains U64_MAX.

In dma_length(), a positive stride added to U64_MAX wraps to a small
value. With size0 == 1, check_mul_overflow() does not trigger and
dma_length() returns 0 instead of U64_MAX. The caller's U64_MAX check
then passes, region_size[] stays 0, and the bounds check in
ethosu_job.c is bypassed, allowing hardware to execute DMA with stale
physical addresses.

Fix by checking for U64_MAX at the start of dma_length() before any
arithmetic, consistent with the sentinel value used throughout the
driver to detect uninitialized fields.

🎖@cveNotify
🚨 CVE-2026-53171
In the Linux kernel, the following vulnerability has been resolved:

accel/ethosu: fix arithmetic issues in dma_length()

dma_length() derives DMA region usage from command stream values and
updates region_size[]:

len = ((len + stride[0]) * size0 + stride[1]) * size1
region_size[region] = max(..., len + dma->offset)

Several arithmetic issues can corrupt the derived region size:

- signed stride values may underflow when added to len
- intermediate multiplications may overflow
- len + dma->offset may overflow during region_size updates
- dma_length() error returns were not validated by the caller

region_size[] is later used by ethosu_job.c to validate command stream
accesses against GEM buffer sizes. Arithmetic wraparound can therefore
under-report region usage and bypass the bounds validation.

Fix by validating signed additions, using overflow helpers for
multiplications and offset updates, and propagating dma_length()
failures to the caller.

🎖@cveNotify
🚨 CVE-2026-53172
In the Linux kernel, the following vulnerability has been resolved:

accel/ethosu: fix IFM region index out-of-bounds in command stream parser

NPU_SET_IFM_REGION extracts the region index with param & 0x7f, giving
a maximum value of 127. However region_size[] and output_region[] in
struct ethosu_validated_cmdstream_info are both sized to
NPU_BASEP_REGION_MAX (8), giving valid indices [0..7].

Every other region assignment in the same switch uses param & 0x7:
NPU_SET_OFM_REGION: st.ofm.region = param & 0x7;
NPU_SET_IFM2_REGION: st.ifm2.region = param & 0x7;
NPU_SET_WEIGHT_REGION: st.weight[0].region = param & 0x7;
NPU_SET_SCALE_REGION: st.scale[0].region = param & 0x7;

The 0x7f mask on IFM is inconsistent and appears to be a typo.

feat_matrix_length() and calc_sizes() use the region index directly
as an array subscript into the kzalloc'd info struct:
info->region_size[fm->region] = max(...);

A userspace caller supplying NPU_SET_IFM_REGION with param > 7 causes
a write up to 127*8 = 1016 bytes past the start of region_size[],
corrupting adjacent kernel heap data.

Fix by applying the same & 0x7 mask used by all other region
assignments.

🎖@cveNotify
🚨 CVE-2026-53173
In the Linux kernel, the following vulnerability has been resolved:

accel/ethosu: fix OOB write in ethosu_gem_cmdstream_copy_and_validate()

The command stream parsing loop increments the index variable a second
time when a 64-bit command word is encountered (bit 14 set), but does
not re-check the loop bound before writing the second word:

for (i = 0; i < size / 4; i++) {
bocmds[i] = cmds[0];
if (cmd & 0x4000) {
i++;
bocmds[i] = cmds[1]; /* unchecked */
}
}

The buffer bocmds is backed by a DMA allocation of exactly size bytes
from drm_gem_dma_create(ddev, size), giving valid indices [0, size/4-1].

When i == size/4 - 1 on entry to an iteration and bit 14 of cmds[0] is
set, bocmds[size/4-1] is written in bounds, i is then incremented to
size/4, and bocmds[size/4] writes four bytes past the end of the
allocation.

Userspace controls both the buffer contents and the size argument via
the ioctl, making this a userspace-triggerable heap out-of-bounds write.

Fix by checking the incremented index against the buffer bound before
the second write and returning -EINVAL if the buffer is too small to
contain the extended command.

🎖@cveNotify
🚨 CVE-2026-53174
In the Linux kernel, the following vulnerability has been resolved:

ovl: keep err zero after successful ovl_cache_get()

ovl_iterate_merged() stores PTR_ERR(cache) in err before checking
IS_ERR(cache). On success err holds the truncated cache pointer and
can be returned as a bogus non-zero error.

The syzbot reproducer reaches this through overlay-on-overlay readdir:

getdents64
iterate_dir(outer overlay file)
ovl_iterate_merged()
ovl_cache_get()
ovl_dir_read_merged()
ovl_dir_read()
iterate_dir(inner overlay file)
ovl_iterate_merged()

Only compute PTR_ERR(cache) on the error path.

🎖@cveNotify
🚨 CVE-2026-53175
In the Linux kernel, the following vulnerability has been resolved:

inet: frags: fix use-after-free caused by the fqdir_pre_exit() flush

On netns teardown, fqdir_pre_exit() walks the fqdir rhashtable and
flushes every fragment queue that is not yet complete using
inet_frag_queue_flush(). That helper frees all the skbs queued on the
fragment queue but does not set INET_FRAG_COMPLETE, and leaves
q->fragments_tail and q->last_run_head pointing at the freed skbs.
The queue itself stays in the rhashtable.

fqdir_pre_exit() first lowers high_thresh to 0 to stop new queue lookups,
but it cannot stop a fragment that already obtained the queue through
inet_frag_find() earlier and stalled just before taking the queue lock.
Once that fragment resumes after the flush and takes the queue lock,
it passes the INET_FRAG_COMPLETE check and then dereferences the freed
fragments_tail. inet_frag_queue_insert() reads FRAG_CB() and ->len of
that pointer and, on the append path, writes ->next_frag, causing a
slab use-after-free. IPv6, nf_conntrack_reasm6 and 6lowpan reassembly
share the same flush path and are affected as well.

Reset rb_fragments, fragments_tail and last_run_head in
inet_frag_queue_flush() so a flushed queue no longer points at the
freed skbs. A fragment that resumes after the flush and takes the
queue lock then finds an empty queue and starts a new run instead of
dereferencing the freed fragments_tail. ip_frag_reinit() already
performed this reset after its own flush, so drop the now duplicate
code there.

🎖@cveNotify
🚨 CVE-2026-53176
In the Linux kernel, the following vulnerability has been resolved:

IB/isert: Reject login PDUs shorter than ISER_HEADERS_LEN

In drivers/infiniband/ulp/isert/ib_isert.c, isert_login_recv_done()
computes the login request payload length as wc->byte_len minus
ISER_HEADERS_LEN with no lower bound, and login_req_len is a signed int.
A remote iSER initiator can post a login Send work request carrying
fewer than ISER_HEADERS_LEN (76) bytes, so the subtraction underflows
and login_req_len becomes negative.

isert_rx_login_req() then reads that negative length back into a signed
int, takes size = min(rx_buflen, MAX_KEY_VALUE_PAIRS), and because the
min() is signed it keeps the negative value; the value is then passed as
the memcpy() length and sign-extended to a multi-gigabyte size_t. The
copy into the 8192-byte login->req_buf runs far out of bounds and
faults, crashing the target node. The login phase precedes iSCSI
authentication, so no credentials are required to reach this path.

Reject any login PDU shorter than ISER_HEADERS_LEN before the
subtraction, mirroring the existing early return on a failed work
completion, so login_req_len can never go negative. The upper bound was
already safe: a posted login buffer cannot deliver more than
ISER_RX_PAYLOAD_SIZE, so the difference stays at or below
MAX_KEY_VALUE_PAIRS and the existing min() clamps it; only the missing
lower bound needs to be added.

🎖@cveNotify
🚨 CVE-2026-53177
In the Linux kernel, the following vulnerability has been resolved:

bnxt_en: Fix NULL pointer dereference

PCIe errors detected by a Root Port or Downstream Port cause error
recovery services to run on all subordinate devices regardless of
administrative state.

The .error_detected() callback, bnxt_io_error_detected(), disables
and synchronizes IRQs via bnxt_disable_int_sync(), which calls
bnxt_cp_num_to_irq_num() to map completion rings to IRQs using
bp->bnapi.

Since bp->bnapi is allocated on NIC open and freed on NIC close, PCIe
error recovery on a closed NIC can dereference a NULL pointer.

Check if bp->bnapi is NULL before disabling and synchronizing IRQs.

🎖@cveNotify
🚨 CVE-2026-53178
In the Linux kernel, the following vulnerability has been resolved:

staging: rtl8723bs: rtw_mlme: add bounds checks before ie_length subtraction

Add guards to ensure ie_length is large enough before subtracting
fixed IE offsets to prevent unsigned integer underflow.

🎖@cveNotify
🚨 CVE-2026-53179
In the Linux kernel, the following vulnerability has been resolved:

staging: rtl8723bs: fix buffer over-read in rtw_update_protection

rtw_update_protection() is called with a pointer offset into the
ies buffer but the full ie_length is passed, causing a potential
buffer over-read.

🎖@cveNotify
🚨 CVE-2026-53180
In the Linux kernel, the following vulnerability has been resolved:

timers/migration: Fix livelock in tmigr_handle_remote_up()

tmigr_handle_remote_cpu() skips timer_expire_remote() when cpu ==
smp_processor_id(), assuming the local softirq path already handled this
CPU's timers.

This assumption is wrong because jiffies can advance after the handling of
the CPU's global timers in run_timer_base(BASE_GLOBAL) and before
tmigr_handle_remote() evaluates the expiry times.

As a consequence a timer which expires after the CPU local timer wheel
advanced and becomes expired in the remote handling is ignored and the
callback is never invoked and removed from the timer wheel.

What's worse is that fetch_next_timer_interrupt_remote() keeps reporting it
as expired, and the event is re-queued with expires == now on each
iteration. The goto-again loop spins indefinitely.

Fix this by calling timer_expire_remote() unconditionally. That's minimal
overhead for the common case as __run_timer_base() returns immediately if
there is nothing to expire in the local wheel.

[ tglx: Amend change log and add a comment ]

🎖@cveNotify
🚨 CVE-2026-53181
In the Linux kernel, the following vulnerability has been resolved:

vsock/vmci: fix sk_ack_backlog leak on failed handshake

When vmci_transport_recv_connecting_server() returns an error,
vmci_transport_recv_listen() calls vsock_remove_pending() but never
calls sk_acceptq_removed(). This leaves sk_ack_backlog incremented
permanently.

Repeated handshake failures (malformed packets, queue pair alloc
failure, event subscribe failure) cause sk_ack_backlog to climb
toward sk_max_ack_backlog. Once it reaches the limit the listener
permanently refuses all new connections with -ECONNREFUSED, a
silent denial of service requiring a process restart to recover.

The two existing sk_acceptq_removed() calls in af_vsock.c do not
cover this path: line 764 checks vsock_is_pending() which returns
false after vsock_remove_pending(), and line 1889 is only reached
on successful accept().

Fix by balancing sk_acceptq_added() with sk_acceptq_removed() on
the error path.

🎖@cveNotify
🚨 CVE-2026-53182
In the Linux kernel, the following vulnerability has been resolved:

wifi: nl80211: reject oversized EMA RNR lists

nl80211_parse_rnr_elems() stores the parsed element count in a
u8-backed cfg80211_rnr_elems::cnt field and uses that count to size
the flexible array allocation.

Reject nested NL80211_ATTR_EMA_RNR_ELEMS input once the count reaches
255, before incrementing it again. This keeps the parser aligned with
the data structure it fills and matches the existing bound check used
by nl80211_parse_mbssid_elems().

🎖@cveNotify
🚨 CVE-2026-53183
In the Linux kernel, the following vulnerability has been resolved:

mptcp: allow subflow rcv wnd to shrink

In MPTCP connection, the `window` field in the TCP header refers to the
MPTCP-level rcv_nxt and it's right edge should not move backward. Such
constraint is enforced at DSS option generation time.

At the same time, the TCP stack ensures independently that the TCP-level
rcv wnd right's edge does not move backward. That in turn causes artificial
inflating of the MPTCP rcv window when the incoming data is acked at the
TCP level and is OoO in the MPTCP sequence space (or lands in the backlog).

As a consequence, the incoming traffic can exceed the receiver rcvbuf size
even when the sender is not misbehaving.

Prevent such scenario forcibly allowing the TCP subflow to shrink the
TCP-level rcv wnd regardless of the current netns setting.

🎖@cveNotify
🚨 CVE-2026-53184
In the Linux kernel, the following vulnerability has been resolved:

udp: clear skb->dev before running a sockmap verdict

On the UDP receive path skb->dev is repurposed as dev_scratch (the
truesize/state cache set by udp_set_dev_scratch()), through the
union { struct net_device *dev; unsigned long dev_scratch; } in sk_buff.

When a UDP socket is in a sockmap, sk_data_ready is
sk_psock_verdict_data_ready(), which calls udp_read_skb() -> recv_actor()
(sk_psock_verdict_recv) to run the attached SK_SKB verdict program in softirq.
If that program calls a socket-lookup helper (bpf_sk_lookup_tcp/udp,
bpf_skc_lookup_tcp), bpf_skc_lookup() does:

if (skb->dev)
caller_net = dev_net(skb->dev);

skb->dev still holds the dev_scratch value (a non-NULL integer), so dev_net()
dereferences it as a struct net_device * and the kernel takes a general
protection fault on a non-canonical address in softirq:

Oops: general protection fault, probably for non-canonical address 0x1010000800004a0
CPU: 1 UID: 0 PID: 1406 Comm: syz.2.19 Not tainted 7.1.0-rc6 #1 PREEMPT(full)
RIP: 0010:bpf_skc_lookup net/core/filter.c:7033 [inline]
RIP: 0010:bpf_sk_lookup+0x45/0x160 net/core/filter.c:7047
Call Trace:
<IRQ>
bpf_prog_4675cb904b7071f8+0x12e/0x14e
bpf_prog_run_pin_on_cpu+0xc6/0x1f0
sk_psock_verdict_recv+0x1ba/0x350
udp_read_skb+0x31a/0x370
sk_psock_verdict_data_ready+0x2e3/0x600
__udp_enqueue_schedule_skb+0x4c8/0x650
udpv6_queue_rcv_one_skb+0x3ec/0x740
udp6_unicast_rcv_skb+0x11d/0x140
ip6_protocol_deliver_rcu+0x61e/0x950
ip6_input_finish+0xa9/0x150
NF_HOOK+0x286/0x2f0
ip6_input+0x117/0x220
NF_HOOK+0x286/0x2f0
__netif_receive_skb+0x85/0x200
process_backlog+0x374/0x9a0
__napi_poll+0x4f/0x1c0
net_rx_action+0x3b0/0x770
handle_softirqs+0x15a/0x460
do_softirq+0x57/0x80
</IRQ>

The rmem charge that dev_scratch accounted for is released by skb_recv_udp() on
dequeue, just above, so the scratch is dead by the time recv_actor() runs. Clear
skb->dev so bpf_skc_lookup() falls back to sock_net(skb->sk), which
skb_set_owner_sk_safe() set just above.

🎖@cveNotify
🚨 CVE-2026-53185
In the Linux kernel, the following vulnerability has been resolved:

zram: fix use-after-free in zram_bvec_write_partial()

zram_read_page() picks the sync or async backing device read path based on
whether the parent bio is NULL. zram_bvec_write_partial() passes its
parent bio down, so for ZRAM_WB slots the read is dispatched
asynchronously and zram_read_page() returns 0 while the bio is still in
flight. The caller then runs memcpy_from_bvec(), zram_write_page() and
__free_page() on the buffer, leaving the async read to write into a freed
page.

zram_bvec_read_partial() was switched to NULL in commit 4e3c87b9421d
("zram: fix synchronous reads") for the same reason; the write_partial
counterpart was missed.

🎖@cveNotify