| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
ring-buffer: Fix subbuf resize race with ring buffer readers
trace_buffer subbuf_size is read lockless in ring_buffer_read_page() and
ring_buffer_read_start(), while it can simultaneously be resized with
ring_buffer_subbuf_order_set().
Instead of trace_buffer::subbuf_size, use bpage::order in
ring_buffer_read_start() and ring_buffer_read_page().
In ring_buffer_read_start(), even with resize_disabled, there is still a
possibility of a race with a buffer modification. Hold the trace_buffer
mutex to synchronise with any pending ring buffer order modification.
trace_buffer::subbuf_size is now actually useless, remove it. Also,
create accessors rb_subbuf_capacity() and rb_page_capacity() which
return the actual size available for storing events, while
rb_subbuf_size() returns the actual subbuf page-size. |
| In the Linux kernel, the following vulnerability has been resolved:
ceph: fix UAF in __kick_flushing_caps() on cf entry freed during unlock
list_for_each_entry() iterates ci->i_cap_flush_list but drops
i_ceph_lock to send cap messages. During the unlock window,
handle_cap_flush_ack() can acquire i_ceph_lock, detach cf entries
with tid <= flush_tid from the list, release i_ceph_lock, and free
them via ceph_free_cap_flush() outside any lock. When the original
thread reacquires i_ceph_lock and the for-loop macro advances via
cf = list_next_entry(cf, i_list), it dereferences cf->i_list.next
on freed memory.
The race timeline:
__kick_flushing_caps() handle_cap_flush_ack()
----------------------- -----------------------
holds i_ceph_lock <---
iterates to cf (tid=10)
prepares FLUSH message
drops i_ceph_lock <---
__send_cap() ── FLUSH(tid=10)
MDS sends FLUSH_ACK(tid=10)
---> acquires i_ceph_lock
cf->tid(10) <= flush_tid(10),
detaches cf from i_cap_flush_list
drops i_ceph_lock
ceph_free_cap_flush(cf) <- frees it!
acquires i_ceph_lock <---
for-loop advances:
cf = list_next_entry(cf, i_list)
-- UAF on freed cf->i_list.next
The cf was just sent by __kick_flushing_caps itself via __send_cap().
The MDS may respond with FLUSH_ACK quickly enough that
handle_cap_flush_ack() frees cf before __kick_flushing_caps can
finish the iteration.
Fix by converting to a manual while loop: save the next pointer
under i_ceph_lock before dropping it, then use the saved pointer
after reacquiring, so the potentially-freed cf is never accessed again. |
| 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:
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:
quota: Fix race of dquot_scan_active() with quota deactivation
dquot_scan_active() can race with quota deactivation in
quota_release_workfn() like:
CPU0 (quota_release_workfn) CPU1 (dquot_scan_active)
============================== ==============================
spin_lock(&dq_list_lock);
list_replace_init(
&releasing_dquots, &rls_head);
/* dquot X on rls_head,
dq_count == 0,
DQ_ACTIVE_B still set */
spin_unlock(&dq_list_lock);
synchronize_srcu(&dquot_srcu);
spin_lock(&dq_list_lock);
list_for_each_entry(dquot,
&inuse_list, dq_inuse) {
/* finds dquot X */
dquot_active(X) -> true
atomic_inc(&X->dq_count);
}
spin_unlock(&dq_list_lock);
spin_lock(&dq_list_lock);
dquot = list_first_entry(&rls_head);
WARN_ON_ONCE(atomic_read(&dquot->dq_count));
The problem is not only a cosmetic one as under memory pressure the
caller of dquot_scan_active() can end up working on freed dquot.
Fix the problem by making sure the dquot is removed from releasing list
when we acquire a reference to it. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: ctnetlink: ensure safe access to master conntrack
Holding reference on the expectation is not sufficient, the master
conntrack object can just go away, making exp->master invalid.
To access exp->master safely:
- Grab the nf_conntrack_expect_lock, this gets serialized with
clean_from_lists() which also holds this lock when the master
conntrack goes away.
- Hold reference on master conntrack via nf_conntrack_find_get().
Not so easy since the master tuple to look up for the master conntrack
is not available in the existing problematic paths.
This patch goes for extending the nf_conntrack_expect_lock section
to address this issue for simplicity, in the cases that are described
below this is just slightly extending the lock section.
The add expectation command already holds a reference to the master
conntrack from ctnetlink_create_expect().
However, the delete expectation command needs to grab the spinlock
before looking up for the expectation. Expand the existing spinlock
section to address this to cover the expectation lookup. Note that,
the nf_ct_expect_iterate_net() calls already grabs the spinlock while
iterating over the expectation table, which is correct.
The get expectation command needs to grab the spinlock to ensure master
conntrack does not go away. This also expands the existing spinlock
section to cover the expectation lookup too. I needed to move the
netlink skb allocation out of the spinlock to keep it GFP_KERNEL.
For the expectation events, the IPEXP_DESTROY event is already delivered
under the spinlock, just move the delivery of IPEXP_NEW under the
spinlock too because the master conntrack event cache is reached through
exp->master.
While at it, add lockdep notations to help identify what codepaths need
to grab the spinlock. |
| In the Linux kernel, the following vulnerability has been resolved:
net: add proper RCU protection to /proc/net/ptype
Yin Fengwei reported an RCU stall in ptype_seq_show() and provided
a patch.
Real issue is that ptype_seq_next() and ptype_seq_show() violate
RCU rules.
ptype_seq_show() runs under rcu_read_lock(), and reads pt->dev
to get device name without any barrier.
At the same time, concurrent writers can remove a packet_type structure
(which is correctly freed after an RCU grace period) and clear pt->dev
without an RCU grace period.
Define ptype_iter_state to carry a dev pointer along seq_net_private:
struct ptype_iter_state {
struct seq_net_private p;
struct net_device *dev; // added in this patch
};
We need to record the device pointer in ptype_get_idx() and
ptype_seq_next() so that ptype_seq_show() is safe against
concurrent pt->dev changes.
We also need to add full RCU protection in ptype_seq_next().
(Missing READ_ONCE() when reading list.next values)
Many thanks to Dong Chenchen for providing a repro. |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: qat - protect service table iterations with service_lock
The service_table list is protected by service_lock when entries are
added or removed (in adf_service_add() and adf_service_remove()), but
several functions iterate over the list without holding this lock.
A concurrent adf_service_register() or adf_service_unregister() call
could modify the list during traversal, leading to list corruption or
a use-after-free.
Fix this by holding service_lock across all list_for_each_entry()
iterations of service_table in adf_dev_init(), adf_dev_start(),
adf_dev_stop(), adf_dev_shutdown(), adf_dev_restarting_notify(),
adf_dev_restarted_notify(), and adf_error_notifier().
The lock ordering is safe: callers of the static helpers (adf_dev_up()
and adf_dev_down()) acquire state_lock before service_lock, and no
event_hld callback or service_lock holder ever acquires state_lock in
the reverse order. |
| In the Linux kernel, the following vulnerability has been resolved:
netfs: Fix missing barriers when accessing stream->subrequests locklessly
The list of subrequests attached to stream->subrequests is accessed without
locks by netfs_collect_read_results() and netfs_collect_write_results(),
and then they access subreq->flags without taking a barrier after getting
the subreq pointer from the list. Relatedly, the functions that build the
list don't use any sort of write barrier when constructing the list to make
sure that the NETFS_SREQ_IN_PROGRESS flag is perceived to be set first if
no lock is taken.
Fix this by:
(1) Add a new list_add_tail_release() function that uses a release barrier
to set the pointer to the new member of the list.
(2) Add a new list_first_entry_or_null_acquire() function that uses an
acquire barrier to read the pointer to the first member in a list (or
return NULL).
(3) Use list_add_tail_release() when adding a subreq to ->subrequests.
(4) Use list_first_entry_or_null_acquire() when initially accessing the
front of the list (when an item is removed, the pointer to the new
front iterm is obtained under the same lock). |
| In the Linux kernel, the following vulnerability has been resolved:
s390/vfio_ccw: Selectively expand io_mutex
The io_mutex was defined to serialize the io_regions, but then has
also sort of been associated with the I/O themselves because of
the close relationship they share.
With the handful of races that are possible, the choices are either to:
A) expand the scope of io_mutex to close these remaining windows, or
B) reduce the scope of io_mutex to just io_region, and introduce a new
lock mechanism for the remaining I/O resources
This patch implements A, since B brings with it a lot more interactions
that would need to be tracked and kept in a correct hierarchy. It also
takes advantage of the workqueue element for cp_free() that now gets
called out of fsm_notoper(), which could be invoked out of an interrupt
context and thus cannot acquire a mutex itself. |
| In the Linux kernel, the following vulnerability has been resolved:
tls: handle data disappearing from under the TLS ULP
TLS expects that it owns the receive queue of the TCP socket.
This cannot be guaranteed in case the reader of the TCP socket
entered before the TLS ULP was installed, or uses some non-standard
read API (eg. zerocopy ones). Replace the WARN_ON() and a buggy
early exit (which leaves anchor pointing to a freed skb) with real
error handling. Wipe the parsing state and tell the reader to retry.
We already reload the anchor every time we (re)acquire the socket lock,
so the only condition we need to avoid is an out of bounds read
(not having enough bytes in the socket for previously parsed record len).
If some data was read from under TLS but there's enough in the queue
we'll reload and decrypt what is most likely not a valid TLS record.
Leading to some undefined behavior from TLS perspective (corrupting
a stream? missing an alert? missing an attack?) but no kernel crash
should take place. |
| In the Linux kernel, the following vulnerability has been resolved:
rseq: Prevent hard lockup on granted time slice extension
__exit_to_user_mode_loop() invokes rseq_grant_timeslice_extension() with
interrupts enabled. If the extension is granted it invokes
hrtimer_rearm_deferred_tif() to ensure that a pending deferred hrtimer
rearm is handled before exiting to user space.
Though this invokes __hrtimer_rearm_deferred() which expects to be invoked
with interrupts disabled as it takes hrtimer_cpu_base::lock with
raw_spin_lock(). That's a livelock waiting to happen and caught by lockdep:
WARNING: ./include/linux/hrtimer_rearm.h:17 at irqentry_exit, CPU#1: slice_test
WARNING: inconsistent lock state
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
Prevent this by disabling interrupts around the invocation of
hrtimer_rearm_deferred_tif() in rseq_grant_timeslice_extension().
[ tglx: Massaged change log ] |
| A vulnerability was identified in Linux Kernel up to 4.19.316/5.4.278/5.10.220/5.15.161. This impacts the function tcp_getsockopt/tcp_setsockopt of the component TCP Handler. Such manipulation leads to race condition. A high complexity level is associated with this attack. The exploitability is said to be difficult. The vulnerability was introduced in 2.6.12, commit 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ("Linux-2.6.12-rc2"). Upgrading to version 4.19.317, 5.4.279, 5.10.221, 5.15.162 and 6.1 will fix this issue. The name of the patch is fcd31dd8291b23d713245947ec2b2d99ef07aef2/3b32f265805a49071e2c4568a524398ba22bf93c/d529193eae979a7bf2255cd9fe68b7af7a1c91b3/5bb642cc3355ffd3c8bca0a8bd8e6e65bcc2091c/f49cd2f4d6170d27a2c61f1fecb03d8a70c91f57. The affected component should be upgraded. |
| Race condition in the JavaScript Engine component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1. |
| In the Linux kernel, the following vulnerability has been resolved:
tracing: Fix race between update_event_fields and, event_define_fields
The following sequence may leads race between event_define_fields()
and update_event_fields():
CPU0 (loads module A) CPU1 (loads module B)
=============================== ===============================
load_module(A) load_module(B)
notifier_call_chain notifier_call_chain
trace_module_notify trace_module_notify
mutex_lock(&event_mutex) trace_event_update_all()
trace_module_add_events(A) down_write(&trace_event_sem)
__register_event(call_A)
__add_event_to_tracers(call_A)
event_define_fields(call_A)
for each f: list_for_each_entry(field,
list_add(&f->link, &class->fields, link)
&class->fields) field = class->fields->next;
Where access to the class->fields is not protected by the event_mutex in
trace_event_update_all().
This produces the following panic:
Unable to handle kernel access ... at virtual address 0000000000000018
pc : update_event_fields+0xf8/0x368
Call trace:
update_event_fields+0xf8/0x368
trace_event_update_all+0x7c/0x2b4
trace_module_notify+0x4c/0x1dc
notifier_call_chain+0x84/0x168
blocking_notifier_call_chain_robust+0x64/0xd4
load_module+0x10c8/0x123c
__arm64_sys_finit_module+0x230/0x31c
Fix by taking event_mutex in trace_event_update_all() before
trace_event_sem. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: SVM: Serialize accesses to the owner and mirror list with separate lock
Interaction between KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM and
KVM_CAP_VM_COPY_ENC_CONTEXT_FROM can cause two separate issues:
- in sev_migrate_from(), when the destination KVM is a mirror, the mirror
entry is moved from the source's list to the owner's mirror_vms list,
without holding the owner's lock unlike other writers of the owner's
mirror list (sev_vm_copy_enc_context_from(), sev_vm_destroy()).
A concurrent COPY or destroy can race with sev_migrate_from() and
corrupt the list.
- In sev_vm_destroy(), the *owner* is still active and could receive
concurrently a KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM that causes
sev->enc_context_owner to change. In this case the incorrect VM
receives kvm_put_kvm().
The second issue needs particular care because the owner could disappear
altogether (even though the race window is impossibly small) between
reading it and locking it. There is thus no way to perform the checks
under the owner lock without putting struct kvm under SLAB_TYPESAFE_BY_RCU
(which would allow kvm_get_kvm_safe() under RCU critical section).
It is much simpler to just use a global lock, since the critical
sections are so small and the new lock is always a leaf lock. |
| In the Linux kernel, the following vulnerability has been resolved:
gpio: mt7621: avoid corruption of shared interrupt trigger state
The bank-shared fields like 'rising' and 'falling' are modified using
non-atomic read-modify-write operations. Since every gpio chip instance
represents an entire bank of 32 pins, if 'mediatek_gpio_irq_type()' is
called concurrently for different IRQs on the same bank a possible overwrite
of each other's configuration is possible. Thus, protect this state with
'gpio_generic_lock_irqsave' lock in the same way it is handled in irp_chip
'mediatek_gpio_irq_mask()' and 'mediatek_gpio_irq_unmask()' callbacks. |
| In the Linux kernel, the following vulnerability has been resolved:
x86/virt/sev: Revert "Drop WBINVD before setting MSR_AMD64_SYSCFG_SNP_EN"
Revert
99cf1fb58e68 ("x86/virt/sev: Drop WBINVD before setting MSR_AMD64_SYSCFG_SNP_EN").
Section 8.8 of the SNP spec says:
Before invoking SNP_INIT_EX with INIT_RMP set to 1, software must ensure
that no CPUs contain dirty cache lines for the memory containing the RMP.
Cachelines can be moved from cache to cache in a dirty state. The
wbinvd_on_all_cpus() before SNP_INIT_EX flushes the caches for each CPU, but
if the IPIs for WBINVD race with this dirty cacheline movement, it is possible
that they may not get flushed, violating the firmware requirement.
Doing wbinvd_on_all_cpus() before setting SNPEn is safer since the RMP
table is not yet in use.
[ Heroically bisected by Srikanth. ]
[ bp: Massage commit message. ] |
| In the Linux kernel, the following vulnerability has been resolved:
drm/fb-helper: Only consider active CRTCs for vblank sync
Only synchronize fbdev output to the vblank of an active CRTC. Go over
the list of CRTCs and pick the first that matches. Fixes warnings as
the one shown below
[ 77.201354] WARNING: drivers/gpu/drm/drm_vblank.c:1320 at drm_crtc_wait_one_vblank+0x194/0x1cc [drm], CPU#1: kworker/1:7/1867
[ 77.201354] omapdrm omapdrm.0: [drm] vblank wait timed out on crtc 0
This currently happens if the fbdev output is not on CRTC 0.
Atomic and non-atomic drivers require distinct code paths. As for other
fbdev operations, implement both and select the correct one at runtime.
Not finding an active CRTC is not a bug. Do not wait in this case, but
flush the display update as before.
v4:
- avoid possible deadlocks with locking context (Sashiko)
v3:
- drop excessive state validation (Jani)
- acquire plane and CRTC mutices (Sashiko)
v2:
- move look-up code into separate helper
- support drivers with legacy modesetting
v1:
- see https://lore.kernel.org/dri-devel/[email protected]/ |
