| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
genirq/cpuhotplug, x86/vector: Prevent vector leak during CPU offline
The absence of IRQD_MOVE_PCNTXT prevents immediate effectiveness of
interrupt affinity reconfiguration via procfs. Instead, the change is
deferred until the next instance of the interrupt being triggered on the
original CPU.
When the interrupt next triggers on the original CPU, the new affinity is
enforced within __irq_move_irq(). A vector is allocated from the new CPU,
but the old vector on the original CPU remains and is not immediately
reclaimed. Instead, apicd->move_in_progress is flagged, and the reclaiming
process is delayed until the next trigger of the interrupt on the new CPU.
Upon the subsequent triggering of the interrupt on the new CPU,
irq_complete_move() adds a task to the old CPU's vector_cleanup list if it
remains online. Subsequently, the timer on the old CPU iterates over its
vector_cleanup list, reclaiming old vectors.
However, a rare scenario arises if the old CPU is outgoing before the
interrupt triggers again on the new CPU.
In that case irq_force_complete_move() is not invoked on the outgoing CPU
to reclaim the old apicd->prev_vector because the interrupt isn't currently
affine to the outgoing CPU, and irq_needs_fixup() returns false. Even
though __vector_schedule_cleanup() is later called on the new CPU, it
doesn't reclaim apicd->prev_vector; instead, it simply resets both
apicd->move_in_progress and apicd->prev_vector to 0.
As a result, the vector remains unreclaimed in vector_matrix, leading to a
CPU vector leak.
To address this issue, move the invocation of irq_force_complete_move()
before the irq_needs_fixup() call to reclaim apicd->prev_vector, if the
interrupt is currently or used to be affine to the outgoing CPU.
Additionally, reclaim the vector in __vector_schedule_cleanup() as well,
following a warning message, although theoretically it should never see
apicd->move_in_progress with apicd->prev_cpu pointing to an offline CPU. |
| In the Linux kernel, the following vulnerability has been resolved:
fork: defer linking file vma until vma is fully initialized
Thorvald reported a WARNING [1]. And the root cause is below race:
CPU 1 CPU 2
fork hugetlbfs_fallocate
dup_mmap hugetlbfs_punch_hole
i_mmap_lock_write(mapping);
vma_interval_tree_insert_after -- Child vma is visible through i_mmap tree.
i_mmap_unlock_write(mapping);
hugetlb_dup_vma_private -- Clear vma_lock outside i_mmap_rwsem!
i_mmap_lock_write(mapping);
hugetlb_vmdelete_list
vma_interval_tree_foreach
hugetlb_vma_trylock_write -- Vma_lock is cleared.
tmp->vm_ops->open -- Alloc new vma_lock outside i_mmap_rwsem!
hugetlb_vma_unlock_write -- Vma_lock is assigned!!!
i_mmap_unlock_write(mapping);
hugetlb_dup_vma_private() and hugetlb_vm_op_open() are called outside
i_mmap_rwsem lock while vma lock can be used in the same time. Fix this
by deferring linking file vma until vma is fully initialized. Those vmas
should be initialized first before they can be used. |
| 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: nft_set_pipapo: walk over current view on netlink dump
The generation mask can be updated while netlink dump is in progress.
The pipapo set backend walk iterator cannot rely on it to infer what
view of the datastructure is to be used. Add notation to specify if user
wants to read/update the set.
Based on patch from Florian Westphal. |
| 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:
netfilter: flowtable: incorrect pppoe tuple
pppoe traffic reaching ingress path does not match the flowtable entry
because the pppoe header is expected to be at the network header offset.
This bug causes a mismatch in the flow table lookup, so pppoe packets
enter the classical forwarding path. |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: Prevent deadlock while disabling aRFS
When disabling aRFS under the `priv->state_lock`, any scheduled
aRFS works are canceled using the `cancel_work_sync` function,
which waits for the work to end if it has already started.
However, while waiting for the work handler, the handler will
try to acquire the `state_lock` which is already acquired.
The worker acquires the lock to delete the rules if the state
is down, which is not the worker's responsibility since
disabling aRFS deletes the rules.
Add an aRFS state variable, which indicates whether the aRFS is
enabled and prevent adding rules when the aRFS is disabled.
Kernel log:
======================================================
WARNING: possible circular locking dependency detected
6.7.0-rc4_net_next_mlx5_5483eb2 #1 Tainted: G I
------------------------------------------------------
ethtool/386089 is trying to acquire lock:
ffff88810f21ce68 ((work_completion)(&rule->arfs_work)){+.+.}-{0:0}, at: __flush_work+0x74/0x4e0
but task is already holding lock:
ffff8884a1808cc0 (&priv->state_lock){+.+.}-{3:3}, at: mlx5e_ethtool_set_channels+0x53/0x200 [mlx5_core]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&priv->state_lock){+.+.}-{3:3}:
__mutex_lock+0x80/0xc90
arfs_handle_work+0x4b/0x3b0 [mlx5_core]
process_one_work+0x1dc/0x4a0
worker_thread+0x1bf/0x3c0
kthread+0xd7/0x100
ret_from_fork+0x2d/0x50
ret_from_fork_asm+0x11/0x20
-> #0 ((work_completion)(&rule->arfs_work)){+.+.}-{0:0}:
__lock_acquire+0x17b4/0x2c80
lock_acquire+0xd0/0x2b0
__flush_work+0x7a/0x4e0
__cancel_work_timer+0x131/0x1c0
arfs_del_rules+0x143/0x1e0 [mlx5_core]
mlx5e_arfs_disable+0x1b/0x30 [mlx5_core]
mlx5e_ethtool_set_channels+0xcb/0x200 [mlx5_core]
ethnl_set_channels+0x28f/0x3b0
ethnl_default_set_doit+0xec/0x240
genl_family_rcv_msg_doit+0xd0/0x120
genl_rcv_msg+0x188/0x2c0
netlink_rcv_skb+0x54/0x100
genl_rcv+0x24/0x40
netlink_unicast+0x1a1/0x270
netlink_sendmsg+0x214/0x460
__sock_sendmsg+0x38/0x60
__sys_sendto+0x113/0x170
__x64_sys_sendto+0x20/0x30
do_syscall_64+0x40/0xe0
entry_SYSCALL_64_after_hwframe+0x46/0x4e
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&priv->state_lock);
lock((work_completion)(&rule->arfs_work));
lock(&priv->state_lock);
lock((work_completion)(&rule->arfs_work));
*** DEADLOCK ***
3 locks held by ethtool/386089:
#0: ffffffff82ea7210 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40
#1: ffffffff82e94c88 (rtnl_mutex){+.+.}-{3:3}, at: ethnl_default_set_doit+0xd3/0x240
#2: ffff8884a1808cc0 (&priv->state_lock){+.+.}-{3:3}, at: mlx5e_ethtool_set_channels+0x53/0x200 [mlx5_core]
stack backtrace:
CPU: 15 PID: 386089 Comm: ethtool Tainted: G I 6.7.0-rc4_net_next_mlx5_5483eb2 #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x60/0xa0
check_noncircular+0x144/0x160
__lock_acquire+0x17b4/0x2c80
lock_acquire+0xd0/0x2b0
? __flush_work+0x74/0x4e0
? save_trace+0x3e/0x360
? __flush_work+0x74/0x4e0
__flush_work+0x7a/0x4e0
? __flush_work+0x74/0x4e0
? __lock_acquire+0xa78/0x2c80
? lock_acquire+0xd0/0x2b0
? mark_held_locks+0x49/0x70
__cancel_work_timer+0x131/0x1c0
? mark_held_locks+0x49/0x70
arfs_del_rules+0x143/0x1e0 [mlx5_core]
mlx5e_arfs_disable+0x1b/0x30 [mlx5_core]
mlx5e_ethtool_set_channels+0xcb/0x200 [mlx5_core]
ethnl_set_channels+0x28f/0x3b0
ethnl_default_set_doit+0xec/0x240
genl_family_rcv_msg_doit+0xd0/0x120
genl_rcv_msg+0x188/0x2c0
? ethn
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
tun: limit printing rate when illegal packet received by tun dev
vhost_worker will call tun call backs to receive packets. If too many
illegal packets arrives, tun_do_read will keep dumping packet contents.
When console is enabled, it will costs much more cpu time to dump
packet and soft lockup will be detected.
net_ratelimit mechanism can be used to limit the dumping rate.
PID: 33036 TASK: ffff949da6f20000 CPU: 23 COMMAND: "vhost-32980"
#0 [fffffe00003fce50] crash_nmi_callback at ffffffff89249253
#1 [fffffe00003fce58] nmi_handle at ffffffff89225fa3
#2 [fffffe00003fceb0] default_do_nmi at ffffffff8922642e
#3 [fffffe00003fced0] do_nmi at ffffffff8922660d
#4 [fffffe00003fcef0] end_repeat_nmi at ffffffff89c01663
[exception RIP: io_serial_in+20]
RIP: ffffffff89792594 RSP: ffffa655314979e8 RFLAGS: 00000002
RAX: ffffffff89792500 RBX: ffffffff8af428a0 RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000005 RDI: ffffffff8af428a0
RBP: 0000000000002710 R8: 0000000000000004 R9: 000000000000000f
R10: 0000000000000000 R11: ffffffff8acbf64f R12: 0000000000000020
R13: ffffffff8acbf698 R14: 0000000000000058 R15: 0000000000000000
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
#5 [ffffa655314979e8] io_serial_in at ffffffff89792594
#6 [ffffa655314979e8] wait_for_xmitr at ffffffff89793470
#7 [ffffa65531497a08] serial8250_console_putchar at ffffffff897934f6
#8 [ffffa65531497a20] uart_console_write at ffffffff8978b605
#9 [ffffa65531497a48] serial8250_console_write at ffffffff89796558
#10 [ffffa65531497ac8] console_unlock at ffffffff89316124
#11 [ffffa65531497b10] vprintk_emit at ffffffff89317c07
#12 [ffffa65531497b68] printk at ffffffff89318306
#13 [ffffa65531497bc8] print_hex_dump at ffffffff89650765
#14 [ffffa65531497ca8] tun_do_read at ffffffffc0b06c27 [tun]
#15 [ffffa65531497d38] tun_recvmsg at ffffffffc0b06e34 [tun]
#16 [ffffa65531497d68] handle_rx at ffffffffc0c5d682 [vhost_net]
#17 [ffffa65531497ed0] vhost_worker at ffffffffc0c644dc [vhost]
#18 [ffffa65531497f10] kthread at ffffffff892d2e72
#19 [ffffa65531497f50] ret_from_fork at ffffffff89c0022f |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: restore set elements when delete set fails
From abort path, nft_mapelem_activate() needs to restore refcounters to
the original state. Currently, it uses the set->ops->walk() to iterate
over these set elements. The existing set iterator skips inactive
elements in the next generation, this does not work from the abort path
to restore the original state since it has to skip active elements
instead (not inactive ones).
This patch moves the check for inactive elements to the set iterator
callback, then it reverses the logic for the .activate case which
needs to skip active elements.
Toggle next generation bit for elements when delete set command is
invoked and call nft_clear() from .activate (abort) path to restore the
next generation bit.
The splat below shows an object in mappings memleak:
[43929.457523] ------------[ cut here ]------------
[43929.457532] WARNING: CPU: 0 PID: 1139 at include/net/netfilter/nf_tables.h:1237 nft_setelem_data_deactivate+0xe4/0xf0 [nf_tables]
[...]
[43929.458014] RIP: 0010:nft_setelem_data_deactivate+0xe4/0xf0 [nf_tables]
[43929.458076] Code: 83 f8 01 77 ab 49 8d 7c 24 08 e8 37 5e d0 de 49 8b 6c 24 08 48 8d 7d 50 e8 e9 5c d0 de 8b 45 50 8d 50 ff 89 55 50 85 c0 75 86 <0f> 0b eb 82 0f 0b eb b3 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90
[43929.458081] RSP: 0018:ffff888140f9f4b0 EFLAGS: 00010246
[43929.458086] RAX: 0000000000000000 RBX: ffff8881434f5288 RCX: dffffc0000000000
[43929.458090] RDX: 00000000ffffffff RSI: ffffffffa26d28a7 RDI: ffff88810ecc9550
[43929.458093] RBP: ffff88810ecc9500 R08: 0000000000000001 R09: ffffed10281f3e8f
[43929.458096] R10: 0000000000000003 R11: ffff0000ffff0000 R12: ffff8881434f52a0
[43929.458100] R13: ffff888140f9f5f4 R14: ffff888151c7a800 R15: 0000000000000002
[43929.458103] FS: 00007f0c687c4740(0000) GS:ffff888390800000(0000) knlGS:0000000000000000
[43929.458107] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[43929.458111] CR2: 00007f58dbe5b008 CR3: 0000000123602005 CR4: 00000000001706f0
[43929.458114] Call Trace:
[43929.458118] <TASK>
[43929.458121] ? __warn+0x9f/0x1a0
[43929.458127] ? nft_setelem_data_deactivate+0xe4/0xf0 [nf_tables]
[43929.458188] ? report_bug+0x1b1/0x1e0
[43929.458196] ? handle_bug+0x3c/0x70
[43929.458200] ? exc_invalid_op+0x17/0x40
[43929.458211] ? nft_setelem_data_deactivate+0xd7/0xf0 [nf_tables]
[43929.458271] ? nft_setelem_data_deactivate+0xe4/0xf0 [nf_tables]
[43929.458332] nft_mapelem_deactivate+0x24/0x30 [nf_tables]
[43929.458392] nft_rhash_walk+0xdd/0x180 [nf_tables]
[43929.458453] ? __pfx_nft_rhash_walk+0x10/0x10 [nf_tables]
[43929.458512] ? rb_insert_color+0x2e/0x280
[43929.458520] nft_map_deactivate+0xdc/0x1e0 [nf_tables]
[43929.458582] ? __pfx_nft_map_deactivate+0x10/0x10 [nf_tables]
[43929.458642] ? __pfx_nft_mapelem_deactivate+0x10/0x10 [nf_tables]
[43929.458701] ? __rcu_read_unlock+0x46/0x70
[43929.458709] nft_delset+0xff/0x110 [nf_tables]
[43929.458769] nft_flush_table+0x16f/0x460 [nf_tables]
[43929.458830] nf_tables_deltable+0x501/0x580 [nf_tables] |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: fix memleak in map from abort path
The delete set command does not rely on the transaction object for
element removal, therefore, a combination of delete element + delete set
from the abort path could result in restoring twice the refcount of the
mapping.
Check for inactive element in the next generation for the delete element
command in the abort path, skip restoring state if next generation bit
has been already cleared. This is similar to the activate logic using
the set walk iterator.
[ 6170.286929] ------------[ cut here ]------------
[ 6170.286939] WARNING: CPU: 6 PID: 790302 at net/netfilter/nf_tables_api.c:2086 nf_tables_chain_destroy+0x1f7/0x220 [nf_tables]
[ 6170.287071] Modules linked in: [...]
[ 6170.287633] CPU: 6 PID: 790302 Comm: kworker/6:2 Not tainted 6.9.0-rc3+ #365
[ 6170.287768] RIP: 0010:nf_tables_chain_destroy+0x1f7/0x220 [nf_tables]
[ 6170.287886] Code: df 48 8d 7d 58 e8 69 2e 3b df 48 8b 7d 58 e8 80 1b 37 df 48 8d 7d 68 e8 57 2e 3b df 48 8b 7d 68 e8 6e 1b 37 df 48 89 ef eb c4 <0f> 0b 48 83 c4 08 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 0f
[ 6170.287895] RSP: 0018:ffff888134b8fd08 EFLAGS: 00010202
[ 6170.287904] RAX: 0000000000000001 RBX: ffff888125bffb28 RCX: dffffc0000000000
[ 6170.287912] RDX: 0000000000000003 RSI: ffffffffa20298ab RDI: ffff88811ebe4750
[ 6170.287919] RBP: ffff88811ebe4700 R08: ffff88838e812650 R09: fffffbfff0623a55
[ 6170.287926] R10: ffffffff8311d2af R11: 0000000000000001 R12: ffff888125bffb10
[ 6170.287933] R13: ffff888125bffb10 R14: dead000000000122 R15: dead000000000100
[ 6170.287940] FS: 0000000000000000(0000) GS:ffff888390b00000(0000) knlGS:0000000000000000
[ 6170.287948] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 6170.287955] CR2: 00007fd31fc00710 CR3: 0000000133f60004 CR4: 00000000001706f0
[ 6170.287962] Call Trace:
[ 6170.287967] <TASK>
[ 6170.287973] ? __warn+0x9f/0x1a0
[ 6170.287986] ? nf_tables_chain_destroy+0x1f7/0x220 [nf_tables]
[ 6170.288092] ? report_bug+0x1b1/0x1e0
[ 6170.287986] ? nf_tables_chain_destroy+0x1f7/0x220 [nf_tables]
[ 6170.288092] ? report_bug+0x1b1/0x1e0
[ 6170.288104] ? handle_bug+0x3c/0x70
[ 6170.288112] ? exc_invalid_op+0x17/0x40
[ 6170.288120] ? asm_exc_invalid_op+0x1a/0x20
[ 6170.288132] ? nf_tables_chain_destroy+0x2b/0x220 [nf_tables]
[ 6170.288243] ? nf_tables_chain_destroy+0x1f7/0x220 [nf_tables]
[ 6170.288366] ? nf_tables_chain_destroy+0x2b/0x220 [nf_tables]
[ 6170.288483] nf_tables_trans_destroy_work+0x588/0x590 [nf_tables] |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: Fix mirred deadlock on device recursion
When the mirred action is used on a classful egress qdisc and a packet is
mirrored or redirected to self we hit a qdisc lock deadlock.
See trace below.
[..... other info removed for brevity....]
[ 82.890906]
[ 82.890906] ============================================
[ 82.890906] WARNING: possible recursive locking detected
[ 82.890906] 6.8.0-05205-g77fadd89fe2d-dirty #213 Tainted: G W
[ 82.890906] --------------------------------------------
[ 82.890906] ping/418 is trying to acquire lock:
[ 82.890906] ffff888006994110 (&sch->q.lock){+.-.}-{3:3}, at:
__dev_queue_xmit+0x1778/0x3550
[ 82.890906]
[ 82.890906] but task is already holding lock:
[ 82.890906] ffff888006994110 (&sch->q.lock){+.-.}-{3:3}, at:
__dev_queue_xmit+0x1778/0x3550
[ 82.890906]
[ 82.890906] other info that might help us debug this:
[ 82.890906] Possible unsafe locking scenario:
[ 82.890906]
[ 82.890906] CPU0
[ 82.890906] ----
[ 82.890906] lock(&sch->q.lock);
[ 82.890906] lock(&sch->q.lock);
[ 82.890906]
[ 82.890906] *** DEADLOCK ***
[ 82.890906]
[..... other info removed for brevity....]
Example setup (eth0->eth0) to recreate
tc qdisc add dev eth0 root handle 1: htb default 30
tc filter add dev eth0 handle 1: protocol ip prio 2 matchall \
action mirred egress redirect dev eth0
Another example(eth0->eth1->eth0) to recreate
tc qdisc add dev eth0 root handle 1: htb default 30
tc filter add dev eth0 handle 1: protocol ip prio 2 matchall \
action mirred egress redirect dev eth1
tc qdisc add dev eth1 root handle 1: htb default 30
tc filter add dev eth1 handle 1: protocol ip prio 2 matchall \
action mirred egress redirect dev eth0
We fix this by adding an owner field (CPU id) to struct Qdisc set after
root qdisc is entered. When the softirq enters it a second time, if the
qdisc owner is the same CPU, the packet is dropped to break the loop. |
| In the Linux kernel, the following vulnerability has been resolved:
clk: Get runtime PM before walking tree for clk_summary
Similar to the previous commit, we should make sure that all devices are
runtime resumed before printing the clk_summary through debugfs. Failure
to do so would result in a deadlock if the thread is resuming a device
to print clk state and that device is also runtime resuming in another
thread, e.g the screen is turning on and the display driver is starting
up. We remove the calls to clk_pm_runtime_{get,put}() in this path
because they're superfluous now that we know the devices are runtime
resumed. This also squashes a bug where the return value of
clk_pm_runtime_get() wasn't checked, leading to an RPM count underflow
on error paths. |
| In the Linux kernel, the following vulnerability has been resolved:
fs: sysfs: Fix reference leak in sysfs_break_active_protection()
The sysfs_break_active_protection() routine has an obvious reference
leak in its error path. If the call to kernfs_find_and_get() fails then
kn will be NULL, so the companion sysfs_unbreak_active_protection()
routine won't get called (and would only cause an access violation by
trying to dereference kn->parent if it was called). As a result, the
reference to kobj acquired at the start of the function will never be
released.
Fix the leak by adding an explicit kobject_put() call when kn is NULL. |
| 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: x86: Don't overflow lpage_info when checking attributes
Fix KVM_SET_MEMORY_ATTRIBUTES to not overflow lpage_info array and trigger
KASAN splat, as seen in the private_mem_conversions_test selftest.
When memory attributes are set on a GFN range, that range will have
specific properties applied to the TDP. A huge page cannot be used when
the attributes are inconsistent, so they are disabled for those the
specific huge pages. For internal KVM reasons, huge pages are also not
allowed to span adjacent memslots regardless of whether the backing memory
could be mapped as huge.
What GFNs support which huge page sizes is tracked by an array of arrays
'lpage_info' on the memslot, of ‘kvm_lpage_info’ structs. Each index of
lpage_info contains a vmalloc allocated array of these for a specific
supported page size. The kvm_lpage_info denotes whether a specific huge
page (GFN and page size) on the memslot is supported. These arrays include
indices for unaligned head and tail huge pages.
Preventing huge pages from spanning adjacent memslot is covered by
incrementing the count in head and tail kvm_lpage_info when the memslot is
allocated, but disallowing huge pages for memory that has mixed attributes
has to be done in a more complicated way. During the
KVM_SET_MEMORY_ATTRIBUTES ioctl KVM updates lpage_info for each memslot in
the range that has mismatched attributes. KVM does this a memslot at a
time, and marks a special bit, KVM_LPAGE_MIXED_FLAG, in the kvm_lpage_info
for any huge page. This bit is essentially a permanently elevated count.
So huge pages will not be mapped for the GFN at that page size if the
count is elevated in either case: a huge head or tail page unaligned to
the memslot or if KVM_LPAGE_MIXED_FLAG is set because it has mixed
attributes.
To determine whether a huge page has consistent attributes, the
KVM_SET_MEMORY_ATTRIBUTES operation checks an xarray to make sure it
consistently has the incoming attribute. Since level - 1 huge pages are
aligned to level huge pages, it employs an optimization. As long as the
level - 1 huge pages are checked first, it can just check these and assume
that if each level - 1 huge page contained within the level sized huge
page is not mixed, then the level size huge page is not mixed. This
optimization happens in the helper hugepage_has_attrs().
Unfortunately, although the kvm_lpage_info array representing page size
'level' will contain an entry for an unaligned tail page of size level,
the array for level - 1 will not contain an entry for each GFN at page
size level. The level - 1 array will only contain an index for any
unaligned region covered by level - 1 huge page size, which can be a
smaller region. So this causes the optimization to overflow the level - 1
kvm_lpage_info and perform a vmalloc out of bounds read.
In some cases of head and tail pages where an overflow could happen,
callers skip the operation completely as KVM_LPAGE_MIXED_FLAG is not
required to prevent huge pages as discussed earlier. But for memslots that
are smaller than the 1GB page size, it does call hugepage_has_attrs(). In
this case the huge page is both the head and tail page. The issue can be
observed simply by compiling the kernel with CONFIG_KASAN_VMALLOC and
running the selftest “private_mem_conversions_test”, which produces the
output like the following:
BUG: KASAN: vmalloc-out-of-bounds in hugepage_has_attrs+0x7e/0x110
Read of size 4 at addr ffffc900000a3008 by task private_mem_con/169
Call Trace:
dump_stack_lvl
print_report
? __virt_addr_valid
? hugepage_has_attrs
? hugepage_has_attrs
kasan_report
? hugepage_has_attrs
hugepage_has_attrs
kvm_arch_post_set_memory_attributes
kvm_vm_ioctl
It is a little ambiguous whether the unaligned head page (in the bug case
also the tail page) should be expected to have KVM_LPAGE_MIXED_FLAG set.
It is not functionally required, as the unal
---truncated--- |
| 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:
arm64: hibernate: Fix level3 translation fault in swsusp_save()
On arm64 machines, swsusp_save() faults if it attempts to access
MEMBLOCK_NOMAP memory ranges. This can be reproduced in QEMU using UEFI
when booting with rodata=off debug_pagealloc=off and CONFIG_KFENCE=n:
Unable to handle kernel paging request at virtual address ffffff8000000000
Mem abort info:
ESR = 0x0000000096000007
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x07: level 3 translation fault
Data abort info:
ISV = 0, ISS = 0x00000007, ISS2 = 0x00000000
CM = 0, WnR = 0, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
swapper pgtable: 4k pages, 39-bit VAs, pgdp=00000000eeb0b000
[ffffff8000000000] pgd=180000217fff9803, p4d=180000217fff9803, pud=180000217fff9803, pmd=180000217fff8803, pte=0000000000000000
Internal error: Oops: 0000000096000007 [#1] SMP
Internal error: Oops: 0000000096000007 [#1] SMP
Modules linked in: xt_multiport ipt_REJECT nf_reject_ipv4 xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 libcrc32c iptable_filter bpfilter rfkill at803x snd_hda_codec_hdmi snd_hda_intel snd_intel_dspcfg dwmac_generic stmmac_platform snd_hda_codec stmmac joydev pcs_xpcs snd_hda_core phylink ppdev lp parport ramoops reed_solomon ip_tables x_tables nls_iso8859_1 vfat multipath linear amdgpu amdxcp drm_exec gpu_sched drm_buddy hid_generic usbhid hid radeon video drm_suballoc_helper drm_ttm_helper ttm i2c_algo_bit drm_display_helper cec drm_kms_helper drm
CPU: 0 PID: 3663 Comm: systemd-sleep Not tainted 6.6.2+ #76
Source Version: 4e22ed63a0a48e7a7cff9b98b7806d8d4add7dc0
Hardware name: Greatwall GW-XXXXXX-XXX/GW-XXXXXX-XXX, BIOS KunLun BIOS V4.0 01/19/2021
pstate: 600003c5 (nZCv DAIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : swsusp_save+0x280/0x538
lr : swsusp_save+0x280/0x538
sp : ffffffa034a3fa40
x29: ffffffa034a3fa40 x28: ffffff8000001000 x27: 0000000000000000
x26: ffffff8001400000 x25: ffffffc08113e248 x24: 0000000000000000
x23: 0000000000080000 x22: ffffffc08113e280 x21: 00000000000c69f2
x20: ffffff8000000000 x19: ffffffc081ae2500 x18: 0000000000000000
x17: 6666662074736420 x16: 3030303030303030 x15: 3038666666666666
x14: 0000000000000b69 x13: ffffff9f89088530 x12: 00000000ffffffea
x11: 00000000ffff7fff x10: 00000000ffff7fff x9 : ffffffc08193f0d0
x8 : 00000000000bffe8 x7 : c0000000ffff7fff x6 : 0000000000000001
x5 : ffffffa0fff09dc8 x4 : 0000000000000000 x3 : 0000000000000027
x2 : 0000000000000000 x1 : 0000000000000000 x0 : 000000000000004e
Call trace:
swsusp_save+0x280/0x538
swsusp_arch_suspend+0x148/0x190
hibernation_snapshot+0x240/0x39c
hibernate+0xc4/0x378
state_store+0xf0/0x10c
kobj_attr_store+0x14/0x24
The reason is swsusp_save() -> copy_data_pages() -> page_is_saveable()
-> kernel_page_present() assuming that a page is always present when
can_set_direct_map() is false (all of rodata_full,
debug_pagealloc_enabled() and arm64_kfence_can_set_direct_map() false),
irrespective of the MEMBLOCK_NOMAP ranges. Such MEMBLOCK_NOMAP regions
should not be saved during hibernation.
This problem was introduced by changes to the pfn_valid() logic in
commit a7d9f306ba70 ("arm64: drop pfn_valid_within() and simplify
pfn_valid()").
Similar to other architectures, drop the !can_set_direct_map() check in
kernel_page_present() so that page_is_savable() skips such pages.
[catalin.marinas@arm.com: rework commit message] |
| In the Linux kernel, the following vulnerability has been resolved:
mm/memory-failure: fix deadlock when hugetlb_optimize_vmemmap is enabled
When I did hard offline test with hugetlb pages, below deadlock occurs:
======================================================
WARNING: possible circular locking dependency detected
6.8.0-11409-gf6cef5f8c37f #1 Not tainted
------------------------------------------------------
bash/46904 is trying to acquire lock:
ffffffffabe68910 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_slow_dec+0x16/0x60
but task is already holding lock:
ffffffffabf92ea8 (pcp_batch_high_lock){+.+.}-{3:3}, at: zone_pcp_disable+0x16/0x40
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (pcp_batch_high_lock){+.+.}-{3:3}:
__mutex_lock+0x6c/0x770
page_alloc_cpu_online+0x3c/0x70
cpuhp_invoke_callback+0x397/0x5f0
__cpuhp_invoke_callback_range+0x71/0xe0
_cpu_up+0xeb/0x210
cpu_up+0x91/0xe0
cpuhp_bringup_mask+0x49/0xb0
bringup_nonboot_cpus+0xb7/0xe0
smp_init+0x25/0xa0
kernel_init_freeable+0x15f/0x3e0
kernel_init+0x15/0x1b0
ret_from_fork+0x2f/0x50
ret_from_fork_asm+0x1a/0x30
-> #0 (cpu_hotplug_lock){++++}-{0:0}:
__lock_acquire+0x1298/0x1cd0
lock_acquire+0xc0/0x2b0
cpus_read_lock+0x2a/0xc0
static_key_slow_dec+0x16/0x60
__hugetlb_vmemmap_restore_folio+0x1b9/0x200
dissolve_free_huge_page+0x211/0x260
__page_handle_poison+0x45/0xc0
memory_failure+0x65e/0xc70
hard_offline_page_store+0x55/0xa0
kernfs_fop_write_iter+0x12c/0x1d0
vfs_write+0x387/0x550
ksys_write+0x64/0xe0
do_syscall_64+0xca/0x1e0
entry_SYSCALL_64_after_hwframe+0x6d/0x75
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(pcp_batch_high_lock);
lock(cpu_hotplug_lock);
lock(pcp_batch_high_lock);
rlock(cpu_hotplug_lock);
*** DEADLOCK ***
5 locks held by bash/46904:
#0: ffff98f6c3bb23f0 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x64/0xe0
#1: ffff98f6c328e488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0xf8/0x1d0
#2: ffff98ef83b31890 (kn->active#113){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x100/0x1d0
#3: ffffffffabf9db48 (mf_mutex){+.+.}-{3:3}, at: memory_failure+0x44/0xc70
#4: ffffffffabf92ea8 (pcp_batch_high_lock){+.+.}-{3:3}, at: zone_pcp_disable+0x16/0x40
stack backtrace:
CPU: 10 PID: 46904 Comm: bash Kdump: loaded Not tainted 6.8.0-11409-gf6cef5f8c37f #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x68/0xa0
check_noncircular+0x129/0x140
__lock_acquire+0x1298/0x1cd0
lock_acquire+0xc0/0x2b0
cpus_read_lock+0x2a/0xc0
static_key_slow_dec+0x16/0x60
__hugetlb_vmemmap_restore_folio+0x1b9/0x200
dissolve_free_huge_page+0x211/0x260
__page_handle_poison+0x45/0xc0
memory_failure+0x65e/0xc70
hard_offline_page_store+0x55/0xa0
kernfs_fop_write_iter+0x12c/0x1d0
vfs_write+0x387/0x550
ksys_write+0x64/0xe0
do_syscall_64+0xca/0x1e0
entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7fc862314887
Code: 10 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
RSP: 002b:00007fff19311268 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007fc862314887
RDX: 000000000000000c RSI: 000056405645fe10 RDI: 0000000000000001
RBP: 000056405645fe10 R08: 00007fc8623d1460 R09: 000000007fffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000c
R13: 00007fc86241b780 R14: 00007fc862417600 R15: 00007fc862416a00
In short, below scene breaks the
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
nouveau: fix instmem race condition around ptr stores
Running a lot of VK CTS in parallel against nouveau, once every
few hours you might see something like this crash.
BUG: kernel NULL pointer dereference, address: 0000000000000008
PGD 8000000114e6e067 P4D 8000000114e6e067 PUD 109046067 PMD 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 7 PID: 53891 Comm: deqp-vk Not tainted 6.8.0-rc6+ #27
Hardware name: Gigabyte Technology Co., Ltd. Z390 I AORUS PRO WIFI/Z390 I AORUS PRO WIFI-CF, BIOS F8 11/05/2021
RIP: 0010:gp100_vmm_pgt_mem+0xe3/0x180 [nouveau]
Code: c7 48 01 c8 49 89 45 58 85 d2 0f 84 95 00 00 00 41 0f b7 46 12 49 8b 7e 08 89 da 42 8d 2c f8 48 8b 47 08 41 83 c7 01 48 89 ee <48> 8b 40 08 ff d0 0f 1f 00 49 8b 7e 08 48 89 d9 48 8d 75 04 48 c1
RSP: 0000:ffffac20c5857838 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 00000000004d8001 RCX: 0000000000000001
RDX: 00000000004d8001 RSI: 00000000000006d8 RDI: ffffa07afe332180
RBP: 00000000000006d8 R08: ffffac20c5857ad0 R09: 0000000000ffff10
R10: 0000000000000001 R11: ffffa07af27e2de0 R12: 000000000000001c
R13: ffffac20c5857ad0 R14: ffffa07a96fe9040 R15: 000000000000001c
FS: 00007fe395eed7c0(0000) GS:ffffa07e2c980000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 000000011febe001 CR4: 00000000003706f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
...
? gp100_vmm_pgt_mem+0xe3/0x180 [nouveau]
? gp100_vmm_pgt_mem+0x37/0x180 [nouveau]
nvkm_vmm_iter+0x351/0xa20 [nouveau]
? __pfx_nvkm_vmm_ref_ptes+0x10/0x10 [nouveau]
? __pfx_gp100_vmm_pgt_mem+0x10/0x10 [nouveau]
? __pfx_gp100_vmm_pgt_mem+0x10/0x10 [nouveau]
? __lock_acquire+0x3ed/0x2170
? __pfx_gp100_vmm_pgt_mem+0x10/0x10 [nouveau]
nvkm_vmm_ptes_get_map+0xc2/0x100 [nouveau]
? __pfx_nvkm_vmm_ref_ptes+0x10/0x10 [nouveau]
? __pfx_gp100_vmm_pgt_mem+0x10/0x10 [nouveau]
nvkm_vmm_map_locked+0x224/0x3a0 [nouveau]
Adding any sort of useful debug usually makes it go away, so I hand
wrote the function in a line, and debugged the asm.
Every so often pt->memory->ptrs is NULL. This ptrs ptr is set in
the nv50_instobj_acquire called from nvkm_kmap.
If Thread A and Thread B both get to nv50_instobj_acquire around
the same time, and Thread A hits the refcount_set line, and in
lockstep thread B succeeds at refcount_inc_not_zero, there is a
chance the ptrs value won't have been stored since refcount_set
is unordered. Force a memory barrier here, I picked smp_mb, since
we want it on all CPUs and it's write followed by a read.
v2: use paired smp_rmb/smp_wmb. |
