| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
tick/broadcast: Plug clockevents replacement race
朱恺乾 reported and decoded the following race condition when a broadcast
device is replaced:
CPUA CPUB
__tick_broadcast_oneshot_control()
bc = tick_broadcast_device.evtdev;
tick_install_broadcast_device(dev)
clockevents_exchange_device(cur, dev)
shutdown(cur);
detach(cur);
cur->handler = noop;
tick_broadcast_device.evtdev = dev;
tick_broadcast_set_event(bc, next_event); <- FAIL: arms a detached device.
If the original broadcast device has a restricted interrupt affinity mask
and the last CPU in that mask goes offline then the BUG() in
tick_cleanup_dead_cpu() triggers because the clockevent device is not in
detached state.
The reason for this is that tick_install_broadcast_device() is not
serialized vs. tick broadcast operations.
The obvious cure is to serialize tick_install_broadcast_device() with
tick_broadcast_lock against a concurrent tick broadcast operation.
That requires to split clockevents_exchange_device() into two parts, one
which does the exchange, shutdown and detach operation and the other which
drops the module reference count. This is required because the module
reference cannot be dropped while holding tick_broadcast_lock.
Let clockevents_exchange_device() do both operations as before, but let the
broadcast device code take the two step approach and do the device
exchange under tick_broadcast_lock and drop the module reference count
after releasing it. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: qla2xxx: Serialize NVMe unsol ctx list with a per-fcport lock
The fcport->unsol_ctx_head list is modified from several contexts without
a common lock. Entries are added in qla2xxx_process_purls_iocb() from the
response queue ISR (under the qpair qp_lock), while they are removed from
qla2xxx_process_purls_pkt() (DPC/purex worker), qla_nvme_xmt_ls_rsp()
(NVMe-FC transport callback) and qla_nvme_release_lsrsp_cmd_kref() (SRB
completion). The qpair qp_lock cannot serialize this per-fcport list since
multiqueue adapters add entries through different qpairs, so a concurrent
add and delete (or two concurrent deletes) can corrupt the list pointers.
Introduce a dedicated per-fcport spinlock, unsol_ctx_lock, initialized in
qla2x00_alloc_fcport(), and take it around every list_add_tail()/list_del()
on unsol_ctx_head. The add nests under the existing qp_lock; no delete path
takes qp_lock, so the lock order is consistent and deadlock free. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix races in cifsd thread creation
The cifsd demultiplex thread can run and access tcp_ses before the parent
thread has finished populating tcp_ses, which the worker thread accesses
locklessly.
Also, the kthread_run macro may start the thread before returning the
thread pointer. Because the pointer is part of the structure that the
thread can access, if the kernel is preempted after the thread is spawned,
but before the thread pointer is populated and the thread attempts to exit,
it will sleep, waiting for a SIGKILL signal.
Fix this by moving creation of the thread to after all of tcp_ses'es
fields are populated, and spawning the thread last, using a split
kthread_create/wake_up_process logic. |
| In the Linux kernel, the following vulnerability has been resolved:
PCI: mediatek: Protect root bus removal with rescan lock
Hold the pci_rescan_remove_lock lock while stopping and removing a root bus
to avoid racing with concurrent rescan or hotplug operations triggered via
sysfs. Such races may lead to use-after-free issues or system crashes.
[bhelgaas: commit log] |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix reloc root cleanup in merge_reloc_roots()
If the root we got has zero root refs in its root item, we are resetting
the root's ->reloc_root without using barriers like we do everywhere else.
Sashiko complained about this while reviewing another patch, and it's
correct (see the Link tag below).
Also, we should not clear BTRFS_ROOT_DEAD_RELOC_TREE from the root unless
the root points to the reloc root we have.
Fix this by using clear_reloc_root(), which issues the memory barrier
after setting the root's ->reloc_root to NULL and before clearing the bit
BTRFS_ROOT_DEAD_RELOC_TREE from the root. |
| In the Linux kernel, the following vulnerability has been resolved:
sched/core: Make core-sched flips wait for in-flight selections
Core scheduling's pick_next_task() operates on all sibling rqs under one
acquisition of the shared core-wide lock. A ->pick_task() that releases the
rq lock leaves every sibling __lock momentarily free, letting
__sched_core_flip(false) complete mid-selection and rebind rq_lockp() under
it. The selection resumes on the split locks, touching sibling state it no
longer protects, and __schedule() finally releases a lock that was never
taken while leaking the one that was.
Count in-flight core-wide selections in the leader's rq->core_pick_in_flight
and make __sched_core_flip() wait for the count to drain. The count only
changes under the shared lock, which the flip holds while sampling, so no
other ordering is needed. The wait can repeat while selections overlap, but
the flip backs off between samples and flips are rare cookie-lifetime
events.
sched_core_cpu_deactivate() moves the count to the new leader - a stale copy
left behind would bias it forever if that CPU later returns as its own
leader. |
| In the Linux kernel, the following vulnerability has been resolved:
net/smc: stop killed, freed and out_of_sync sharing a byte
The three connection state flags are single-bit bitfields, so they occupy
one byte of struct smc_connection and every store to one is a
read-modify-write of the other two:
u8 killed : 1;
u8 freed : 1;
u8 out_of_sync : 1;
They are not written under a common lock. smc_cdc_msg_validate() sets
out_of_sync from the receive tasklet, while smc_conn_kill() sets killed
from process context under lock_sock(), and the receive path does not defer
to the backlog when the socket is owned -- smc_cdc_msg_recv() takes only
bh_lock_sock().
Give each flag its own byte so a store no longer touches its neighbours.
All readers test them as booleans and are unchanged. struct smc_connection
grows by two bytes. |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: safely drain sessions during logoff
SMB3 multichannel allows requests for one session to run on multiple
connections. Wait for all channels bound to a session before freeing
shared session objects.
A deferred byte-range lock remains counted as a running request and only
wakes when its file closes. Wake blocked locks during the drain without
unpublishing or modifying their file objects. Synchronous CANCEL requests
must invoke their cancellation callback to wake pending operations, while
CHANGE_NOTIFY completion remains specific to the asynchronous path.
Serialize session teardown with channel registration and previous-session
cleanup, and use atomic work-state transitions so LOGOFF, CANCEL, and
connection teardown invoke cancellation callbacks only once. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: ibss: wait for in-flight TX on disconnect
While leaving an IBSS in ieee80211_ibss_disconnect() mac80211 flushes
stations, turns the carrier off and immediately tells the driver to
leave as well. While there may be synchronize_net() in station flush
and in this code later, packets can still be transmitted due to
cross-CPU race conditions after carrier off is set.
Therefore, it's possible for a race to happen where a TX to the
driver occurs while or after telling it to leave the IBSS. This can
be confusing to drivers, and in the case of iwlwifi leads to an
attempt to use invalid queues.
Move netif_carrier_off() to occur before sta_info_flush() during
IBSS disconnect, and add synchronize_net() if flushing didn't,
so that the synchronize_net() always happens between turning the
carrier off and telling the driver, avoiding this race. |
| In the Linux kernel, the following vulnerability has been resolved:
PCI: plda: Protect root bus removal with rescan lock
Hold the pci_rescan_remove_lock lock while stopping and removing a root bus
to avoid racing with concurrent rescan or hotplug operations triggered via
sysfs. Such races may lead to use-after-free issues or system crashes.
[bhelgaas: commit log] |
| In the Linux kernel, the following vulnerability has been resolved:
mptcp: prevent race between disconnect() and rtx
Sashiko noted that the two event can race, leading to inconsistent
status. Prevent the race using the synchronous timer stop operation. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/slab: take n->list_lock in __slab_try_return_freelist() to avoid race
Commit ba7425312607 ("mm, slab: add an optimistic
__slab_try_return_freelist()") incorrectly assumed that nobody has freed
an object to the slab as long as slab->freelist is NULL and cmpxchg
succeeds.
However, as reported by Hyunwoo Kim [1], other CPUs might have freed
an object to the slab, insert the slab to the partial list, then
allocated an object from the slab, and be in the middle of removing
the slab from the list under n->list_lock.
Since __refill_objects_node() puts the slab back on pc.slabs
outside n->list_lock, it might insert the slab into that list while
the slab is concurrently being removed from n->partial.
This led to a list corruption [1]:
list_add corruption. next->prev should be prev
(ffff888100000248), but was dead000000000122.
(next=ffffea000416e410).
kernel BUG at lib/list_debug.c:29!
Oops: invalid opcode: 0000 [#1] SMP NOPTI
CPU: 1 UID: 65534 PID: 144 Comm: poc Not tainted
7.2.0-16172-gcf72cbb39da8-dirty #1 PREEMPT(lazy)
RIP: 0010:__list_add_valid_or_report+0x80/0xd0
...
Call Trace:
alloc_from_new_slab+0x183/0x300
___slab_alloc+0x31c/0x890
__kmalloc_noprof+0x3d4/0x800
lsm_blob_alloc+0x2d/0x50
security_msg_msg_alloc+0x26/0x90
load_msg+0x1aa/0x210
do_msgsnd+0x91/0x800
do_syscall_64+0x109/0x5d0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
...
Kernel panic - not syncing: Fatal exception
This is a classic ABA problem where cmpxchg succeeds but the state has
changed since __refill_objects_node() took the freelist from the slab.
As Vlastimil Babka mentioned [2], it should be rare to return more than
one slab (due to the racy read of slab->counters in
get_partial_node_bulk()). Therefore, instead of introducing additional
complexity, acquire and release n->list_lock twice in the worst case.
Return the slab directly to the partial list and hold n->list_lock
across the cmpxchg and add_partial(). This is similar to the initial
version of commit ba7425312607 [3]. This is enough to avoid the race as
the list manipulation is serialized by n->list_lock. While at it,
bring back unlikely() hint now that the condition is unlikely. |
| In the Linux kernel, the following vulnerability has been resolved:
nvme: fix racy access to FDP placement id array
nvme_query_fdp_info() is called per-path and therefore prone to races.
It populates head->nr_plids/head->plids for fdp registration.
But nothing protects that pair from concurrent access - two paths scanning
the same namespace can race to populate it.
Avoid the race by moving this initialization work to nvme_alloc_ns_head()
which is called once per shared namespace. |
| In the Linux kernel, the following vulnerability has been resolved:
netfs: Fix readahead synchronisation issues by loading all folios upfront
There are some synchronisation issues that derive from the app thread
adding more folios to the rolling buffer whilst the collector thread is
looking at them or trying to clear them, such as determining the setting of
front_folio_order when the next folio hasn't been added yet,
The reason for the rolling buffer approach is that loading the buffer
upfront and then dropping all the refs just acquired is quite a slow
operation, and loading progressively allows some of the cost to be deferred
until after at least some of the I/O is started.
Instead, a better way is to load all the folios into the rolling buffer
upfront - and then drop the refs later, once the I/O is in progress. (Even
better would be for the refs not to be there at all.)
Fix this by changing the rolling buffer loader to load all the folios
selected by the VM for readahead upfront into the folio queue. The folio
queue is allocated a batch worth at a time as we don't know how many folios
are involved (the readahead_control struct, alas, has a page count, not a
folio count).
The folio refs acquired from readahead are then dropped in bulk once the
first subrequest is dispatched as it's quite a slow operation. The
collector waits for NETFS_RREQ_NEED_PUT_RA_REFS to be cleared so that it
doesn't unlock folios before the xarray has been scanned for them.
This simplifies the buffer handling later and isn't noticeably slower as
the xarray doesn't need to be modified and the folios are all already
pre-locked. |
| In the Linux kernel, the following vulnerability has been resolved:
tracing: Fix subbuf resize races with trace_pipe_raw readers
Concurrent subbuffer resizes may crash trace_pipe_raw readers or leak
uninitialized memory to userspace due to stale size values.
Modify ring_buffer_alloc_read_page() to handle the resizing of an
existing buffer_data_read_page if necessary and add a new
ring_buffer_read_page_size(). This new function enables ring-buffer
buffer_data_read_page users to not call the racy
ring_buffer_subbuf_size_get(). This makes the spare_size member of
ftrace_buffer_info redundant.
Finally, handle buffer_data_read_page/reader_page order discrepancy in
ring_buffer_read_page(). On a mismatch simply copy manually the data to
the buffer_data_read_page. |
| In the Linux kernel, the following vulnerability has been resolved:
coresight: perf: Retrieve path and source from event data
ETM perf callbacks currently use the per-CPU csdev_src pointer, which
can race with updates during device registration and unregistration.
The AUX setup already builds and stores the path in the event data.
Use this path to retrieve the source instead of csdev_src to avoid
the race.
Export coresight_get_source() and add etm_event_get_ctxt_path() to
retrieve the context's path and its source with READ_ONCE() /
WRITE_ONCE() accessors. Give the comments to explain why this
approach is safe when pause or resume callbacks preempt the disable
callback (e.g. via NMI). |
| In the Linux kernel, the following vulnerability has been resolved:
x86/alternatives: Exclude text poking against change_page_attr()
From time to time, the following BUG can be observed
in the x86 alternatives patching code [0]:
> kernel BUG at arch/x86/kernel/alternative.c:2576!
> Oops: invalid opcode: 0000 [#1] SMP NOPTI
> CPU: 0 UID: 0 PID: 355 Comm: (udev-worker) Not tainted 7.1.3-1-default #1 PREEMPT(full) openSUSE Tumbleweed 8c1795b03ec64f997e57a8ad38b1161e3b98da64
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS unknown 02/02/2022
> RIP: 0010:__text_poke+0x2aa/0x450
> Call Trace:
> <TASK>
> smp_text_poke_batch_finish+0x2a7/0x320
> __static_call_transform+0xb7/0x220
> arch_static_call_transform+0x5b/0xb0
> __static_call_init+0xe9/0x270
> static_call_module_notify+0x11f/0x150
> notifier_call_chain+0x61/0xe0
> blocking_notifier_call_chain_robust+0x63/0xc0
> load_module+0x1c92/0x20c0
> init_module_from_file+0xd8/0x140
> idempotent_init_module+0x100/0x2f0
> __x64_sys_finit_module+0x71/0xe0
> do_syscall_64+0xe1/0x610
> entry_SYSCALL_64_after_hwframe+0x76/0x7e
which matches the following BUG_ON() in alternative.c:
/*
* If something went wrong, crash and burn since recovery paths are not
* implemented.
*/
BUG_ON(!pages[0] || (cross_page_boundary && !pages[1]));
This can happen if vmalloc_to_page() fails, for any reason. Such can happen
if text poking races with CPA, which can possibly result in the collapsing
of page tables (or breaking of PMD hugepages). It is not a problem for most
users of vmalloc_to_page() (they solely own the vmalloc'd range) but, when
CONFIG_ARCH_HAS_EXECMEM_ROX=y, various modules own a single execmem vmalloc
range, and can call set_memory_*() in parallel on it. This can happen to
race against __text_poke and cause havoc in vmalloc_to_page().
Fix it by excluding against CPA using the init_mm mmap read lock.
[ dhansen: Fix up SoB ordering. The actual code flow here was:
Pedro=>Lorenzo=>Mike=>Me which is reflected in the SoB chain
now. I *believe* Mike simply picked up Lorenzo's update to
Pedro's post from the Link ] |
| In the Linux kernel, the following vulnerability has been resolved:
sunrpc: defer rq_argp and rq_resp free until after RCU grace period
svc_rqst_free() frees rqstp->rq_argp and rqstp->rq_resp synchronously
via kfree(), but defers the rqstp struct free via kfree_rcu(). After
svc_exit_thread() calls list_del_rcu() and svc_rqst_free(), there is
a window where RCU readers that started before list_del_rcu() can still
traverse the thread list and find the rqstp. These readers (e.g.
nfsd_nl_rpc_status_get_dumpit()) dereference rqstp->rq_argp, which has
already been freed — a use-after-free.
Fix this by moving the kfree of rq_argp and rq_resp into an explicit
call_rcu() callback alongside the struct free. Resources not accessed
by RCU readers (bvec, buffer pages, scratch folio, auth_data) remain
synchronously freed. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/irdma: Replace waitqueue and flag with completion
The driver previously used a waitqueue along with an explicit
request_done flag, but without proper barriers around request_done.
An earlier patch by Gui-Dong Han <hanguidong02@gmail.com> attempted
to fix this by adding the missing memory barriers. Rather than
adding the barriers, this patch replaces the waitqueue+flag with
a completion, which is designed for this exact purpose. |
| A race condition in the ZPA tunnel handler of affected versions of Zscaler Client Connector (ZCC) allows a heap corruption, resulting in a denial of service (client crash) and potentially arbitrary code execution in the context of the ZCC process. |
