| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
drm/vmwgfx: Fix the lifetime of the bo cursor memory
The cleanup can be dispatched while the atomic update is still active,
which means that the memory acquired in the atomic update needs to
not be invalidated by the cleanup. The buffer objects in vmw_plane_state
instead of using the builtin map_and_cache were trying to handle
the lifetime of the mapped memory themselves, leading to crashes.
Use the map_and_cache instead of trying to manage the lifetime of the
buffer objects held by the vmw_plane_state.
Fixes kernel oops'es in IGT's kms_cursor_legacy forked-bo. |
| In the Linux kernel, the following vulnerability has been resolved:
mm: cachestat: fix two shmem bugs
When cachestat on shmem races with swapping and invalidation, there
are two possible bugs:
1) A swapin error can have resulted in a poisoned swap entry in the
shmem inode's xarray. Calling get_shadow_from_swap_cache() on it
will result in an out-of-bounds access to swapper_spaces[].
Validate the entry with non_swap_entry() before going further.
2) When we find a valid swap entry in the shmem's inode, the shadow
entry in the swapcache might not exist yet: swap IO is still in
progress and we're before __remove_mapping; swapin, invalidation,
or swapoff have removed the shadow from swapcache after we saw the
shmem swap entry.
This will send a NULL to workingset_test_recent(). The latter
purely operates on pointer bits, so it won't crash - node 0, memcg
ID 0, eviction timestamp 0, etc. are all valid inputs - but it's a
bogus test. In theory that could result in a false "recently
evicted" count.
Such a false positive wouldn't be the end of the world. But for
code clarity and (future) robustness, be explicit about this case.
Bail on get_shadow_from_swap_cache() returning NULL. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: check/clear fast rx for non-4addr sta VLAN changes
When moving a station out of a VLAN and deleting the VLAN afterwards, the
fast_rx entry still holds a pointer to the VLAN's netdev, which can cause
use-after-free bugs. Fix this by immediately calling ieee80211_check_fast_rx
after the VLAN change. |
| In the Linux kernel, the following vulnerability has been resolved:
cpumap: Zero-initialise xdp_rxq_info struct before running XDP program
When running an XDP program that is attached to a cpumap entry, we don't
initialise the xdp_rxq_info data structure being used in the xdp_buff
that backs the XDP program invocation. Tobias noticed that this leads to
random values being returned as the xdp_md->rx_queue_index value for XDP
programs running in a cpumap.
This means we're basically returning the contents of the uninitialised
memory, which is bad. Fix this by zero-initialising the rxq data
structure before running the XDP program. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: bridge: confirm multicast packets before passing them up the stack
conntrack nf_confirm logic cannot handle cloned skbs referencing
the same nf_conn entry, which will happen for multicast (broadcast)
frames on bridges.
Example:
macvlan0
|
br0
/ \
ethX ethY
ethX (or Y) receives a L2 multicast or broadcast packet containing
an IP packet, flow is not yet in conntrack table.
1. skb passes through bridge and fake-ip (br_netfilter)Prerouting.
-> skb->_nfct now references a unconfirmed entry
2. skb is broad/mcast packet. bridge now passes clones out on each bridge
interface.
3. skb gets passed up the stack.
4. In macvlan case, macvlan driver retains clone(s) of the mcast skb
and schedules a work queue to send them out on the lower devices.
The clone skb->_nfct is not a copy, it is the same entry as the
original skb. The macvlan rx handler then returns RX_HANDLER_PASS.
5. Normal conntrack hooks (in NF_INET_LOCAL_IN) confirm the orig skb.
The Macvlan broadcast worker and normal confirm path will race.
This race will not happen if step 2 already confirmed a clone. In that
case later steps perform skb_clone() with skb->_nfct already confirmed (in
hash table). This works fine.
But such confirmation won't happen when eb/ip/nftables rules dropped the
packets before they reached the nf_confirm step in postrouting.
Pablo points out that nf_conntrack_bridge doesn't allow use of stateful
nat, so we can safely discard the nf_conn entry and let inet call
conntrack again.
This doesn't work for bridge netfilter: skb could have a nat
transformation. Also bridge nf prevents re-invocation of inet prerouting
via 'sabotage_in' hook.
Work around this problem by explicit confirmation of the entry at LOCAL_IN
time, before upper layer has a chance to clone the unconfirmed entry.
The downside is that this disables NAT and conntrack helpers.
Alternative fix would be to add locking to all code parts that deal with
unconfirmed packets, but even if that could be done in a sane way this
opens up other problems, for example:
-m physdev --physdev-out eth0 -j SNAT --snat-to 1.2.3.4
-m physdev --physdev-out eth1 -j SNAT --snat-to 1.2.3.5
For multicast case, only one of such conflicting mappings will be
created, conntrack only handles 1:1 NAT mappings.
Users should set create a setup that explicitly marks such traffic
NOTRACK (conntrack bypass) to avoid this, but we cannot auto-bypass
them, ruleset might have accept rules for untracked traffic already,
so user-visible behaviour would change. |
| In the Linux kernel, the following vulnerability has been resolved:
rtnetlink: fix error logic of IFLA_BRIDGE_FLAGS writing back
In the commit d73ef2d69c0d ("rtnetlink: let rtnl_bridge_setlink checks
IFLA_BRIDGE_MODE length"), an adjustment was made to the old loop logic
in the function `rtnl_bridge_setlink` to enable the loop to also check
the length of the IFLA_BRIDGE_MODE attribute. However, this adjustment
removed the `break` statement and led to an error logic of the flags
writing back at the end of this function.
if (have_flags)
memcpy(nla_data(attr), &flags, sizeof(flags));
// attr should point to IFLA_BRIDGE_FLAGS NLA !!!
Before the mentioned commit, the `attr` is granted to be IFLA_BRIDGE_FLAGS.
However, this is not necessarily true fow now as the updated loop will let
the attr point to the last NLA, even an invalid NLA which could cause
overflow writes.
This patch introduces a new variable `br_flag` to save the NLA pointer
that points to IFLA_BRIDGE_FLAGS and uses it to resolve the mentioned
error logic. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: nl80211: reject iftype change with mesh ID change
It's currently possible to change the mesh ID when the
interface isn't yet in mesh mode, at the same time as
changing it into mesh mode. This leads to an overwrite
of data in the wdev->u union for the interface type it
currently has, causing cfg80211_change_iface() to do
wrong things when switching.
We could probably allow setting an interface to mesh
while setting the mesh ID at the same time by doing a
different order of operations here, but realistically
there's no userspace that's going to do this, so just
disallow changes in iftype when setting mesh ID. |
| In the Linux kernel, the following vulnerability has been resolved:
mptcp: fix data races on remote_id
Similar to the previous patch, address the data race on
remote_id, adding the suitable ONCE annotations. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nft_flow_offload: reset dst in route object after setting up flow
dst is transferred to the flow object, route object does not own it
anymore. Reset dst in route object, otherwise if flow_offload_add()
fails, error path releases dst twice, leading to a refcount underflow. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: Fix use-after-free bugs caused by sco_sock_timeout
When the sco connection is established and then, the sco socket
is releasing, timeout_work will be scheduled to judge whether
the sco disconnection is timeout. The sock will be deallocated
later, but it is dereferenced again in sco_sock_timeout. As a
result, the use-after-free bugs will happen. The root cause is
shown below:
Cleanup Thread | Worker Thread
sco_sock_release |
sco_sock_close |
__sco_sock_close |
sco_sock_set_timer |
schedule_delayed_work |
sco_sock_kill | (wait a time)
sock_put(sk) //FREE | sco_sock_timeout
| sock_hold(sk) //USE
The KASAN report triggered by POC is shown below:
[ 95.890016] ==================================================================
[ 95.890496] BUG: KASAN: slab-use-after-free in sco_sock_timeout+0x5e/0x1c0
[ 95.890755] Write of size 4 at addr ffff88800c388080 by task kworker/0:0/7
...
[ 95.890755] Workqueue: events sco_sock_timeout
[ 95.890755] Call Trace:
[ 95.890755] <TASK>
[ 95.890755] dump_stack_lvl+0x45/0x110
[ 95.890755] print_address_description+0x78/0x390
[ 95.890755] print_report+0x11b/0x250
[ 95.890755] ? __virt_addr_valid+0xbe/0xf0
[ 95.890755] ? sco_sock_timeout+0x5e/0x1c0
[ 95.890755] kasan_report+0x139/0x170
[ 95.890755] ? update_load_avg+0xe5/0x9f0
[ 95.890755] ? sco_sock_timeout+0x5e/0x1c0
[ 95.890755] kasan_check_range+0x2c3/0x2e0
[ 95.890755] sco_sock_timeout+0x5e/0x1c0
[ 95.890755] process_one_work+0x561/0xc50
[ 95.890755] worker_thread+0xab2/0x13c0
[ 95.890755] ? pr_cont_work+0x490/0x490
[ 95.890755] kthread+0x279/0x300
[ 95.890755] ? pr_cont_work+0x490/0x490
[ 95.890755] ? kthread_blkcg+0xa0/0xa0
[ 95.890755] ret_from_fork+0x34/0x60
[ 95.890755] ? kthread_blkcg+0xa0/0xa0
[ 95.890755] ret_from_fork_asm+0x11/0x20
[ 95.890755] </TASK>
[ 95.890755]
[ 95.890755] Allocated by task 506:
[ 95.890755] kasan_save_track+0x3f/0x70
[ 95.890755] __kasan_kmalloc+0x86/0x90
[ 95.890755] __kmalloc+0x17f/0x360
[ 95.890755] sk_prot_alloc+0xe1/0x1a0
[ 95.890755] sk_alloc+0x31/0x4e0
[ 95.890755] bt_sock_alloc+0x2b/0x2a0
[ 95.890755] sco_sock_create+0xad/0x320
[ 95.890755] bt_sock_create+0x145/0x320
[ 95.890755] __sock_create+0x2e1/0x650
[ 95.890755] __sys_socket+0xd0/0x280
[ 95.890755] __x64_sys_socket+0x75/0x80
[ 95.890755] do_syscall_64+0xc4/0x1b0
[ 95.890755] entry_SYSCALL_64_after_hwframe+0x67/0x6f
[ 95.890755]
[ 95.890755] Freed by task 506:
[ 95.890755] kasan_save_track+0x3f/0x70
[ 95.890755] kasan_save_free_info+0x40/0x50
[ 95.890755] poison_slab_object+0x118/0x180
[ 95.890755] __kasan_slab_free+0x12/0x30
[ 95.890755] kfree+0xb2/0x240
[ 95.890755] __sk_destruct+0x317/0x410
[ 95.890755] sco_sock_release+0x232/0x280
[ 95.890755] sock_close+0xb2/0x210
[ 95.890755] __fput+0x37f/0x770
[ 95.890755] task_work_run+0x1ae/0x210
[ 95.890755] get_signal+0xe17/0xf70
[ 95.890755] arch_do_signal_or_restart+0x3f/0x520
[ 95.890755] syscall_exit_to_user_mode+0x55/0x120
[ 95.890755] do_syscall_64+0xd1/0x1b0
[ 95.890755] entry_SYSCALL_64_after_hwframe+0x67/0x6f
[ 95.890755]
[ 95.890755] The buggy address belongs to the object at ffff88800c388000
[ 95.890755] which belongs to the cache kmalloc-1k of size 1024
[ 95.890755] The buggy address is located 128 bytes inside of
[ 95.890755] freed 1024-byte region [ffff88800c388000, ffff88800c388400)
[ 95.890755]
[ 95.890755] The buggy address belongs to the physical page:
[ 95.890755] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88800c38a800 pfn:0xc388
[ 95.890755] head: order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
[ 95.890755] ano
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: use timestamp to check for set element timeout
Add a timestamp field at the beginning of the transaction, store it
in the nftables per-netns area.
Update set backend .insert, .deactivate and sync gc path to use the
timestamp, this avoids that an element expires while control plane
transaction is still unfinished.
.lookup and .update, which are used from packet path, still use the
current time to check if the element has expired. And .get path and dump
also since this runs lockless under rcu read size lock. Then, there is
async gc which also needs to check the current time since it runs
asynchronously from a workqueue. |
| In the Linux kernel, the following vulnerability has been resolved:
pstore: inode: Only d_invalidate() is needed
Unloading a modular pstore backend with records in pstorefs would
trigger the dput() double-drop warning:
WARNING: CPU: 0 PID: 2569 at fs/dcache.c:762 dput.part.0+0x3f3/0x410
Using the combo of d_drop()/dput() (as mentioned in
Documentation/filesystems/vfs.rst) isn't the right approach here, and
leads to the reference counting problem seen above. Use d_invalidate()
and update the code to not bother checking for error codes that can
never happen.
--- |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: rtl8xxxu: add cancel_work_sync() for c2hcmd_work
The workqueue might still be running, when the driver is stopped. To
avoid a use-after-free, call cancel_work_sync() in rtl8xxxu_stop(). |
| In the Linux kernel, the following vulnerability has been resolved:
octeontx2-af: Use separate handlers for interrupts
For PF to AF interrupt vector and VF to AF vector same
interrupt handler is registered which is causing race condition.
When two interrupts are raised to two CPUs at same time
then two cores serve same event corrupting the data. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: Fix potential data-race in __nft_expr_type_get()
nft_unregister_expr() can concurrent with __nft_expr_type_get(),
and there is not any protection when iterate over nf_tables_expressions
list in __nft_expr_type_get(). Therefore, there is potential data-race
of nf_tables_expressions list entry.
Use list_for_each_entry_rcu() to iterate over nf_tables_expressions
list in __nft_expr_type_get(), and use rcu_read_lock() in the caller
nft_expr_type_get() to protect the entire type query process. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: Fix potential data-race in __nft_obj_type_get()
nft_unregister_obj() can concurrent with __nft_obj_type_get(),
and there is not any protection when iterate over nf_tables_objects
list in __nft_obj_type_get(). Therefore, there is potential data-race
of nf_tables_objects list entry.
Use list_for_each_entry_rcu() to iterate over nf_tables_objects
list in __nft_obj_type_get(), and use rcu_read_lock() in the caller
nft_obj_type_get() to protect the entire type query process. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: flowtable: validate pppoe header
Ensure there is sufficient room to access the protocol field of the
PPPoe header. Validate it once before the flowtable lookup, then use a
helper function to access protocol field. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: x86/pmu: Disable support for adaptive PEBS
Drop support for virtualizing adaptive PEBS, as KVM's implementation is
architecturally broken without an obvious/easy path forward, and because
exposing adaptive PEBS can leak host LBRs to the guest, i.e. can leak
host kernel addresses to the guest.
Bug #1 is that KVM doesn't account for the upper 32 bits of
IA32_FIXED_CTR_CTRL when (re)programming fixed counters, e.g
fixed_ctrl_field() drops the upper bits, reprogram_fixed_counters()
stores local variables as u8s and truncates the upper bits too, etc.
Bug #2 is that, because KVM _always_ sets precise_ip to a non-zero value
for PEBS events, perf will _always_ generate an adaptive record, even if
the guest requested a basic record. Note, KVM will also enable adaptive
PEBS in individual *counter*, even if adaptive PEBS isn't exposed to the
guest, but this is benign as MSR_PEBS_DATA_CFG is guaranteed to be zero,
i.e. the guest will only ever see Basic records.
Bug #3 is in perf. intel_pmu_disable_fixed() doesn't clear the upper
bits either, i.e. leaves ICL_FIXED_0_ADAPTIVE set, and
intel_pmu_enable_fixed() effectively doesn't clear ICL_FIXED_0_ADAPTIVE
either. I.e. perf _always_ enables ADAPTIVE counters, regardless of what
KVM requests.
Bug #4 is that adaptive PEBS *might* effectively bypass event filters set
by the host, as "Updated Memory Access Info Group" records information
that might be disallowed by userspace via KVM_SET_PMU_EVENT_FILTER.
Bug #5 is that KVM doesn't ensure LBR MSRs hold guest values (or at least
zeros) when entering a vCPU with adaptive PEBS, which allows the guest
to read host LBRs, i.e. host RIPs/addresses, by enabling "LBR Entries"
records.
Disable adaptive PEBS support as an immediate fix due to the severity of
the LBR leak in particular, and because fixing all of the bugs will be
non-trivial, e.g. not suitable for backporting to stable kernels.
Note! This will break live migration, but trying to make KVM play nice
with live migration would be quite complicated, wouldn't be guaranteed to
work (i.e. KVM might still kill/confuse the guest), and it's not clear
that there are any publicly available VMMs that support adaptive PEBS,
let alone live migrate VMs that support adaptive PEBS, e.g. QEMU doesn't
support PEBS in any capacity. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: x86/mmu: Write-protect L2 SPTEs in TDP MMU when clearing dirty status
Check kvm_mmu_page_ad_need_write_protect() when deciding whether to
write-protect or clear D-bits on TDP MMU SPTEs, so that the TDP MMU
accounts for any role-specific reasons for disabling D-bit dirty logging.
Specifically, TDP MMU SPTEs must be write-protected when the TDP MMU is
being used to run an L2 (i.e. L1 has disabled EPT) and PML is enabled.
KVM always disables PML when running L2, even when L1 and L2 GPAs are in
the some domain, so failing to write-protect TDP MMU SPTEs will cause
writes made by L2 to not be reflected in the dirty log.
[sean: massage shortlog and changelog, tweak ternary op formatting] |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: Always flush async #PF workqueue when vCPU is being destroyed
Always flush the per-vCPU async #PF workqueue when a vCPU is clearing its
completion queue, e.g. when a VM and all its vCPUs is being destroyed.
KVM must ensure that none of its workqueue callbacks is running when the
last reference to the KVM _module_ is put. Gifting a reference to the
associated VM prevents the workqueue callback from dereferencing freed
vCPU/VM memory, but does not prevent the KVM module from being unloaded
before the callback completes.
Drop the misguided VM refcount gifting, as calling kvm_put_kvm() from
async_pf_execute() if kvm_put_kvm() flushes the async #PF workqueue will
result in deadlock. async_pf_execute() can't return until kvm_put_kvm()
finishes, and kvm_put_kvm() can't return until async_pf_execute() finishes:
WARNING: CPU: 8 PID: 251 at virt/kvm/kvm_main.c:1435 kvm_put_kvm+0x2d/0x320 [kvm]
Modules linked in: vhost_net vhost vhost_iotlb tap kvm_intel kvm irqbypass
CPU: 8 PID: 251 Comm: kworker/8:1 Tainted: G W 6.6.0-rc1-e7af8d17224a-x86/gmem-vm #119
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Workqueue: events async_pf_execute [kvm]
RIP: 0010:kvm_put_kvm+0x2d/0x320 [kvm]
Call Trace:
<TASK>
async_pf_execute+0x198/0x260 [kvm]
process_one_work+0x145/0x2d0
worker_thread+0x27e/0x3a0
kthread+0xba/0xe0
ret_from_fork+0x2d/0x50
ret_from_fork_asm+0x11/0x20
</TASK>
---[ end trace 0000000000000000 ]---
INFO: task kworker/8:1:251 blocked for more than 120 seconds.
Tainted: G W 6.6.0-rc1-e7af8d17224a-x86/gmem-vm #119
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/8:1 state:D stack:0 pid:251 ppid:2 flags:0x00004000
Workqueue: events async_pf_execute [kvm]
Call Trace:
<TASK>
__schedule+0x33f/0xa40
schedule+0x53/0xc0
schedule_timeout+0x12a/0x140
__wait_for_common+0x8d/0x1d0
__flush_work.isra.0+0x19f/0x2c0
kvm_clear_async_pf_completion_queue+0x129/0x190 [kvm]
kvm_arch_destroy_vm+0x78/0x1b0 [kvm]
kvm_put_kvm+0x1c1/0x320 [kvm]
async_pf_execute+0x198/0x260 [kvm]
process_one_work+0x145/0x2d0
worker_thread+0x27e/0x3a0
kthread+0xba/0xe0
ret_from_fork+0x2d/0x50
ret_from_fork_asm+0x11/0x20
</TASK>
If kvm_clear_async_pf_completion_queue() actually flushes the workqueue,
then there's no need to gift async_pf_execute() a reference because all
invocations of async_pf_execute() will be forced to complete before the
vCPU and its VM are destroyed/freed. And that in turn fixes the module
unloading bug as __fput() won't do module_put() on the last vCPU reference
until the vCPU has been freed, e.g. if closing the vCPU file also puts the
last reference to the KVM module.
Note that kvm_check_async_pf_completion() may also take the work item off
the completion queue and so also needs to flush the work queue, as the
work will not be seen by kvm_clear_async_pf_completion_queue(). Waiting
on the workqueue could theoretically delay a vCPU due to waiting for the
work to complete, but that's a very, very small chance, and likely a very
small delay. kvm_arch_async_page_present_queued() unconditionally makes a
new request, i.e. will effectively delay entering the guest, so the
remaining work is really just:
trace_kvm_async_pf_completed(addr, cr2_or_gpa);
__kvm_vcpu_wake_up(vcpu);
mmput(mm);
and mmput() can't drop the last reference to the page tables if the vCPU is
still alive, i.e. the vCPU won't get stuck tearing down page tables.
Add a helper to do the flushing, specifically to deal with "wakeup all"
work items, as they aren't actually work items, i.e. are never placed in a
workqueue. Trying to flush a bogus workqueue entry rightly makes
__flush_work() complain (kudos to whoever added that sanity check).
Note, commit 5f6de5cbebee ("KVM: Prevent module exit until al
---truncated--- |
