In the Linux kernel, the following vulnerability has been resolved:
vfio/cdx: Serialize VFIO_DEVICE_SET_IRQS with a per-device mutex
vfio_cdx_set_msi_trigger() reads vdev->config_msi and operates on the
vdev->cdx_irqs array based on its value, but provides no serialization
against concurrent VFIO_DEVICE_SET_IRQS ioctls. Two callers can race
such that one observes config_msi as set while another clears it and
frees cdx_irqs via vfio_cdx_msi_disable(), resulting in a use-after-free
of the cdx_irqs array.
Add a cdx_irqs_lock mutex to struct vfio_cdx_device and acquire it in
vfio_cdx_set_msi_trigger(), which is the single chokepoint through
which all updates to config_msi, cdx_irqs, and msi_count flow, covering
both the ioctl path and the close-device cleanup path. This keeps the
test of config_msi atomic with the subsequent enable, disable, or
trigger operations.
Drop the pre-call !cdx_irqs test from vfio_cdx_irqs_cleanup() as part
of this change: the optimization it provided is redundant with the
!config_msi early-return inside vfio_cdx_msi_disable(), and leaving the
test in place would be an unsynchronized read of state the new lock is
meant to protect.
In the Linux kernel, the following vulnerability has been resolved:
mm/damon/core: fix damon_call() vs kdamond_fn() exit race
Patch series "mm/damon/core: fix damon_call()/damos_walk() vs kdmond exit
race".
damon_call() and damos_walk() can leak memory and/or deadlock when they
race with kdamond terminations. Fix those.
This patch (of 2);
When kdamond_fn() main loop is finished, the function cancels all
remaining damon_call() requests and unset the damon_ctx->kdamond so that
API callers and API functions themselves can know the context is
terminated. damon_call() adds the caller's request to the queue first.
After that, it shows if the kdamond of the damon_ctx is still running
(damon_ctx->kdamond is set). Only if the kdamond is running, damon_call()
starts waiting for the kdamond's handling of the newly added request.
The damon_call() requests registration and damon_ctx->kdamond unset are
protected by different mutexes, though. Hence, damon_call() could race
with damon_ctx->kdamond unset, and result in deadlocks.
For example, let's suppose kdamond successfully finished the damon_call()
requests cancelling. Right after that, damon_call() is called for the
context. It registers the new request, and shows the context is still
running, because damon_ctx->kdamond unset is not yet done. Hence the
damon_call() caller starts waiting for the handling of the request.
However, the kdamond is already on the termination steps, so it never
handles the new request. As a result, the damon_call() caller threads
infinitely waits.
Fix this by introducing another damon_ctx field, namely
call_controls_obsolete. It is protected by the
damon_ctx->call_controls_lock, which protects damon_call() requests
registration. Initialize (unset) it in kdamond_fn() before letting
damon_start() returns and set it just before the cancelling of remaining
damon_call() requests is executed. damon_call() reads the obsolete field
under the lock and avoids adding a new request.
After this change, only requests that are guaranteed to be handled or
cancelled are registered. Hence the after-registration DAMON context
termination check is no longer needed. Remove it together.
Note that the deadlock will not happen when damon_call() is called for
repeat mode request. In tis case, damon_call() returns instead of waiting
for the handling when the request registration succeeds and it shows the
kdamond is running. However, if the request also has dealloc_on_cancel,
the request memory would be leaked.
The issue is found by sashiko [1].
In the Linux kernel, the following vulnerability has been resolved:
net: qrtr: ns: Limit the maximum number of lookups
Current code does no bound checking on the number of lookups a client can
perform. Though the code restricts the lookups to local clients, there is
still a possibility of a malicious local client sending a flood of
NEW_LOOKUP messages over the same socket.
Fix this issue by limiting the maximum number of lookups to 64 globally.
Since the nameserver allows only atmost one local observer, this global
lookup count will ensure that the lookups stay within the limit.
Note that, limit of 64 is chosen based on the current platform
requirements. If requirement changes in the future, this limit can be
increased.
In the Linux kernel, the following vulnerability has been resolved:
net/smc: avoid early lgr access in smc_clc_wait_msg
A CLC decline can be received while the handshake is still in an early
stage, before the connection has been associated with a link group.
The decline handling in smc_clc_wait_msg() updates link-group level sync
state for first-contact declines, but that state only exists after link
group setup has completed. Guard the link-group update accordingly and
keep the per-socket peer diagnosis handling unchanged.
This preserves the existing sync_err handling for established link-group
contexts and avoids touching link-group state before it is available.
In the Linux kernel, the following vulnerability has been resolved:
crypto: algif_aead - snapshot IV for async AEAD requests
AF_ALG AEAD AIO requests currently use the socket-wide IV buffer during
request processing. For async requests, later socket activity can
update that shared state before the original request has fully
completed, which can lead to inconsistent IV handling.
Snapshot the IV into per-request storage when preparing the AEAD
request, so in-flight operations no longer depend on mutable socket
state.
In the Linux kernel, the following vulnerability has been resolved:
mm/slab: return NULL early from kmalloc_nolock() in NMI on UP
On UP kernels (!CONFIG_SMP), spin_trylock() is a no-op that
unconditionally succeeds even when the lock is already held. As a
result, kmalloc_nolock() called from NMI context can re-enter the slab
allocator and acquire n->list_lock that the interrupted context is
already holding, corrupting slab state.
With CONFIG_DEBUG_SPINLOCK on UP, the following BUG is triggered with
the slub_kunit test module:
BUG: spinlock trylock failure on UP on CPU#0, kunit_try_catch/243
[...]
Call Trace:
<NMI>
dump_stack_lvl+0x3f/0x60
do_raw_spin_trylock+0x41/0x50
_raw_spin_trylock+0x24/0x50
get_from_partial_node+0x120/0x4d0
___slab_alloc+0x8a/0x4c0
kmalloc_nolock_noprof+0x164/0x310
[...]
</NMI>
Fix this by returning NULL early when invoked from NMI on a UP kernel.
In the Linux kernel, the following vulnerability has been resolved:
EDAC/versalnet: Fix device_node leak in mc_probe()
of_parse_phandle() returns a device_node reference that must be released with
of_node_put(). The original code never freed r5_core_node on any exit path,
causing a memory leak.
Fix this by using the automatic cleanup attribute __free(device_node) which
ensures of_node_put() is called when the variable goes out of scope.
In the Linux kernel, the following vulnerability has been resolved:
remoteproc: xlnx: Only access buffer information if IPI is buffered
In the receive callback check if message is NULL to prevent
possibility of crash by NULL pointer dereferencing.
In the Linux kernel, the following vulnerability has been resolved:
mm: fix deferred split queue races during migration
migrate_folio_move() records the deferred split queue state from src and
replays it on dst. Replaying it after remove_migration_ptes(src, dst, 0)
makes dst visible before it is requeued, so a concurrent rmap-removal path
can mark dst partially mapped and trip the WARN in deferred_split_folio().
Move the requeue before remove_migration_ptes() so dst is back on the
deferred split queue before it becomes visible again.
Because migration still holds dst locked at that point, teach
deferred_split_scan() to requeue a folio when folio_trylock() fails.
Otherwise a fully mapped underused folio can be dequeued by the shrinker
and silently lost from split_queue.
[ziy@nvidia.com: move the comment]
In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: stop parsing UAC2 rates at MAX_NR_RATES
parse_uac2_sample_rate_range() caps the number of enumerated
rates at MAX_NR_RATES, but it only breaks out of the current
rate loop. A malformed UAC2 RANGE response with additional
triplets continues parsing the remaining triplets and repeatedly
prints "invalid uac2 rates" while probe still holds
register_mutex.
Stop the whole parse once the cap is reached and return the
number of rates collected so far.