Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
misc: fastrpc: fix DMA address corruption due to find_vma misuse
fastrpc_get_args() uses find_vma() to look up the VMA for a user-provided
pointer and compute a DMA address offset. When the address falls in a gap
before the returned VMA, (ptr & PAGE_MASK) - vma->vm_start underflows,
corrupting the DMA address sent to the DSP.
Replace find_vma() with vma_lookup(), which returns NULL when the address
is not contained within any VMA.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
misc: fastrpc: fix use-after-free race in fastrpc_map_create
fastrpc_map_lookup returns a raw pointer after releasing fl->lock. The
caller fastrpc_map_create then calls fastrpc_map_get (kref_get_unless_zero)
on this unprotected pointer. A concurrent MEM_UNMAP can free the map
between the lock release and the kref operation, resulting in a
use-after-free on the freed slab object.
Restore the take_ref parameter to fastrpc_map_lookup so the reference
is acquired atomically under fl->lock before the pointer is exposed to
the caller.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
misc: fastrpc: fix use-after-free of fastrpc_user in workqueue context
There is a race between fastrpc_device_release() and the workqueue
that processes DSP responses. When the user closes the file descriptor,
fastrpc_device_release() frees the fastrpc_user structure. Concurrently,
an in-flight DSP invocation can complete and fastrpc_rpmsg_callback()
schedules context cleanup via schedule_work(&ctx->put_work). If the
workqueue runs fastrpc_context_free() in parallel with or after
fastrpc_device_release() has freed the user structure, it dereferences
the freed fastrpc_user. Depending on the state of the context at the
time of the race, any one of the following accesses can be hit:
1. fastrpc_buf_free() calls fastrpc_ipa_to_dma_addr(buf->fl->cctx, ...)
to strip the SID bits from the stored IOVA before passing the
physical address to dma_free_coherent().
2. fastrpc_free_map() reads map->fl->cctx->vmperms[0].vmid to
reconstruct the source permission bitmask needed for the
qcom_scm_assign_mem() call that returns memory from the DSP VM
back to HLOS.
3. fastrpc_free_map() acquires map->fl->lock to safely remove the
map node from the fl->maps list.
The resulting use-after-free manifests as:
pc : fastrpc_buf_free+0x38/0x80 [fastrpc]
lr : fastrpc_context_free+0xa8/0x1b0 [fastrpc]
fastrpc_context_free+0xa8/0x1b0 [fastrpc]
fastrpc_context_put_wq+0x78/0xa0 [fastrpc]
process_one_work+0x180/0x450
worker_thread+0x26c/0x388
Add kref-based reference counting to fastrpc_user. Have each invoke
context take a reference on the user at allocation time and release it
when the context is freed. Release the initial reference in
fastrpc_device_release() at file close. Move the teardown of the user
structure — freeing pending contexts, maps, mmaps, and the channel
context reference — into the kref release callback fastrpc_user_free(),
so that it runs only when the last reference is dropped, regardless of
whether that happens at device close or after the final in-flight
context completes.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
memcg: use round-robin victim selection in refill_stock
Harry Yoo reported that get_random_u32_below() is not safe to call in the
nmi context and memcg charge draining can happen in nmi context.
More specifically get_random_u32_below() is neither reentrant- nor
NMI-safe: it acquires a per-cpu local_lock via local_lock_irqsave() on the
batched_entropy_u32 state. An NMI that lands on a CPU mid-update of the
ChaCha batch state and recurses into the random subsystem would corrupt
that state. The memcg_stock local_trylock prevents re-entry on the percpu
stock itself, but cannot protect an unrelated subsystem's per-cpu lock.
Replace the random pick with a per-cpu round-robin counter stored in
memcg_stock_pcp and serialized by the same local_trylock that already
guards cached[] and nr_pages[]. No atomics, no random calls, no extra
locks needed.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
locking/rtmutex: Skip remove_waiter() when waiter is not enqueued
syzbot triggered the following splat in remove_waiter() via
FUTEX_CMP_REQUEUE_PI:
KASAN: null-ptr-deref in range [0x0000000000000a88-0x0000000000000a8f]
class_raw_spinlock_constructor
remove_waiter+0x159/0x1200 kernel/locking/rtmutex.c:1561
rt_mutex_start_proxy_lock+0x103/0x120
futex_requeue+0x10e4/0x20d0
__x64_sys_futex+0x34f/0x4d0
task_blocks_on_rt_mutex() does not arm the waiter upon deadlock detection,
leaving waiter->task nil, where 3bfdc63936dd ("rtmutex: Use waiter::task instead
of current in remove_waiter()") made this fatal.
Furthermore, rt_mutex_start_proxy_lock() should not be calling into remove_waiter()
upon a successfully grabbing the rtmutex. 1a1fb985f2e2 ("futex: Handle early deadlock
return correctly"), moved the remove_waiter() out of __rt_mutex_start_proxy_lock()
(where 'ret' was only ever 0 or < 0) into the wrapper. Tighten this check to
account for try_to_take_rt_mutex().
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-25
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.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-25
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.
CVSS Score
7.5
EPSS Score
0.004
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
thunderbolt: Validate XDomain request packet size before type cast
tb_xdp_handle_request() casts the received packet buffer to
protocol-specific structs without verifying that the allocation
is large enough for the target type. A peer can send a minimal
XDomain packet that passes the generic header length check but is
shorter than the struct accessed after the cast, causing out-of-
bounds reads from the kmemdup allocation.
Plumb the packet length through xdomain_request_work and validate
it against the expected struct size before each cast.
CVSS Score
8.1
EPSS Score
0.003
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
thunderbolt: Clamp XDomain response data copy to allocation size
tb_xdp_properties_request() derives the per-packet copy length from
the response header without checking that it fits in the previously
allocated data buffer. A malicious peer can set its length field
larger than the declared data_length, causing memcpy to write past
the kcalloc allocation.
Clamp the per-packet copy length so that the cumulative offset
never exceeds data_len.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
thunderbolt: Bound root directory content to block size
__tb_property_parse_dir() does not check that content_offset +
content_len fits within block_len for the root directory case.
When rootdir->length equals or exceeds block_len - 2, the entry
loop reads past the allocated property block.
Add a bounds check after computing content_offset and content_len
to reject directories whose content extends past the block.
CVSS Score
7.1
EPSS Score
0.001
Published
2026-06-25