In the Linux kernel, the following vulnerability has been resolved:
x86/fpu: Clear XSTATE_BV[i] in guest XSAVE state whenever XFD[i]=1
When loading guest XSAVE state via KVM_SET_XSAVE, and when updating XFD in
response to a guest WRMSR, clear XFD-disabled features in the saved (or to
be restored) XSTATE_BV to ensure KVM doesn't attempt to load state for
features that are disabled via the guest's XFD. Because the kernel
executes XRSTOR with the guest's XFD, saving XSTATE_BV[i]=1 with XFD[i]=1
will cause XRSTOR to #NM and panic the kernel.
E.g. if fpu_update_guest_xfd() sets XFD without clearing XSTATE_BV:
------------[ cut here ]------------
WARNING: arch/x86/kernel/traps.c:1524 at exc_device_not_available+0x101/0x110, CPU#29: amx_test/848
Modules linked in: kvm_intel kvm irqbypass
CPU: 29 UID: 1000 PID: 848 Comm: amx_test Not tainted 6.19.0-rc2-ffa07f7fd437-x86_amx_nm_xfd_non_init-vm #171 NONE
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:exc_device_not_available+0x101/0x110
Call Trace:
<TASK>
asm_exc_device_not_available+0x1a/0x20
RIP: 0010:restore_fpregs_from_fpstate+0x36/0x90
switch_fpu_return+0x4a/0xb0
kvm_arch_vcpu_ioctl_run+0x1245/0x1e40 [kvm]
kvm_vcpu_ioctl+0x2c3/0x8f0 [kvm]
__x64_sys_ioctl+0x8f/0xd0
do_syscall_64+0x62/0x940
entry_SYSCALL_64_after_hwframe+0x4b/0x53
</TASK>
---[ end trace 0000000000000000 ]---
This can happen if the guest executes WRMSR(MSR_IA32_XFD) to set XFD[18] = 1,
and a host IRQ triggers kernel_fpu_begin() prior to the vmexit handler's
call to fpu_update_guest_xfd().
and if userspace stuffs XSTATE_BV[i]=1 via KVM_SET_XSAVE:
------------[ cut here ]------------
WARNING: arch/x86/kernel/traps.c:1524 at exc_device_not_available+0x101/0x110, CPU#14: amx_test/867
Modules linked in: kvm_intel kvm irqbypass
CPU: 14 UID: 1000 PID: 867 Comm: amx_test Not tainted 6.19.0-rc2-2dace9faccd6-x86_amx_nm_xfd_non_init-vm #168 NONE
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:exc_device_not_available+0x101/0x110
Call Trace:
<TASK>
asm_exc_device_not_available+0x1a/0x20
RIP: 0010:restore_fpregs_from_fpstate+0x36/0x90
fpu_swap_kvm_fpstate+0x6b/0x120
kvm_load_guest_fpu+0x30/0x80 [kvm]
kvm_arch_vcpu_ioctl_run+0x85/0x1e40 [kvm]
kvm_vcpu_ioctl+0x2c3/0x8f0 [kvm]
__x64_sys_ioctl+0x8f/0xd0
do_syscall_64+0x62/0x940
entry_SYSCALL_64_after_hwframe+0x4b/0x53
</TASK>
---[ end trace 0000000000000000 ]---
The new behavior is consistent with the AMX architecture. Per Intel's SDM,
XSAVE saves XSTATE_BV as '0' for components that are disabled via XFD
(and non-compacted XSAVE saves the initial configuration of the state
component):
If XSAVE, XSAVEC, XSAVEOPT, or XSAVES is saving the state component i,
the instruction does not generate #NM when XCR0[i] = IA32_XFD[i] = 1;
instead, it operates as if XINUSE[i] = 0 (and the state component was
in its initial state): it saves bit i of XSTATE_BV field of the XSAVE
header as 0; in addition, XSAVE saves the initial configuration of the
state component (the other instructions do not save state component i).
Alternatively, KVM could always do XRSTOR with XFD=0, e.g. by using
a constant XFD based on the set of enabled features when XSAVEing for
a struct fpu_guest. However, having XSTATE_BV[i]=1 for XFD-disabled
features can only happen in the above interrupt case, or in similar
scenarios involving preemption on preemptible kernels, because
fpu_swap_kvm_fpstate()'s call to save_fpregs_to_fpstate() saves the
outgoing FPU state with the current XFD; and that is (on all but the
first WRMSR to XFD) the guest XFD.
Therefore, XFD can only go out of sync with XSTATE_BV in the above
interrupt case, or in similar scenarios involving preemption on
preemptible kernels, and it we can consider it (de facto) part of KVM
ABI that KVM_GET_XSAVE returns XSTATE_BV[i]=0 for XFD-disabled features.
[Move clea
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
ASoC: tlv320adcx140: fix null pointer
The "snd_soc_component" in "adcx140_priv" was only used once but never
set. It was only used for reaching "dev" which is already present in
"adcx140_priv".
In the Linux kernel, the following vulnerability has been resolved:
ipv4: ip_gre: make ipgre_header() robust
Analog to commit db5b4e39c4e6 ("ip6_gre: make ip6gre_header() robust")
Over the years, syzbot found many ways to crash the kernel
in ipgre_header() [1].
This involves team or bonding drivers ability to dynamically
change their dev->needed_headroom and/or dev->hard_header_len
In this particular crash mld_newpack() allocated an skb
with a too small reserve/headroom, and by the time mld_sendpack()
was called, syzbot managed to attach an ipgre device.
[1]
skbuff: skb_under_panic: text:ffffffff89ea3cb7 len:2030915468 put:2030915372 head:ffff888058b43000 data:ffff887fdfa6e194 tail:0x120 end:0x6c0 dev:team0
kernel BUG at net/core/skbuff.c:213 !
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 1322 Comm: kworker/1:9 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: mld mld_ifc_work
RIP: 0010:skb_panic+0x157/0x160 net/core/skbuff.c:213
Call Trace:
<TASK>
skb_under_panic net/core/skbuff.c:223 [inline]
skb_push+0xc3/0xe0 net/core/skbuff.c:2641
ipgre_header+0x67/0x290 net/ipv4/ip_gre.c:897
dev_hard_header include/linux/netdevice.h:3436 [inline]
neigh_connected_output+0x286/0x460 net/core/neighbour.c:1618
NF_HOOK_COND include/linux/netfilter.h:307 [inline]
ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247
NF_HOOK+0x9e/0x380 include/linux/netfilter.h:318
mld_sendpack+0x8d4/0xe60 net/ipv6/mcast.c:1855
mld_send_cr net/ipv6/mcast.c:2154 [inline]
mld_ifc_work+0x83e/0xd60 net/ipv6/mcast.c:2693
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
In the Linux kernel, the following vulnerability has been resolved:
dmaengine: idxd: fix device leaks on compat bind and unbind
Make sure to drop the reference taken when looking up the idxd device as
part of the compat bind and unbind sysfs interface.
In the Linux kernel, the following vulnerability has been resolved:
net: can: j1939: j1939_xtp_rx_rts_session_active(): deactivate session upon receiving the second rts
Since j1939_session_deactivate_activate_next() in j1939_tp_rxtimer() is
called only when the timer is enabled, we need to call
j1939_session_deactivate_activate_next() if we cancelled the timer.
Otherwise, refcount for j1939_session leaks, which will later appear as
| unregister_netdevice: waiting for vcan0 to become free. Usage count = 2.
problem.
In the Linux kernel, the following vulnerability has been resolved:
net/sched: sch_qfq: do not free existing class in qfq_change_class()
Fixes qfq_change_class() error case.
cl->qdisc and cl should only be freed if a new class and qdisc
were allocated, or we risk various UAF.
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: Fix crash on profile change rollback failure
mlx5e_netdev_change_profile can fail to attach a new profile and can
fail to rollback to old profile, in such case, we could end up with a
dangling netdev with a fully reset netdev_priv. A retry to change
profile, e.g. another attempt to call mlx5e_netdev_change_profile via
switchdev mode change, will crash trying to access the now NULL
priv->mdev.
This fix allows mlx5e_netdev_change_profile() to handle previous
failures and an empty priv, by not assuming priv is valid.
Pass netdev and mdev to all flows requiring
mlx5e_netdev_change_profile() and avoid passing priv.
In mlx5e_netdev_change_profile() check if current priv is valid, and if
not, just attach the new profile without trying to access the old one.
This fixes the following oops, when enabling switchdev mode for the 2nd
time after first time failure:
## Enabling switchdev mode first time:
mlx5_core 0012:03:00.1: E-Switch: Supported tc chains and prios offload
workqueue: Failed to create a rescuer kthread for wq "mlx5e": -EINTR
mlx5_core 0012:03:00.1: mlx5e_netdev_init_profile:6214:(pid 37199): mlx5e_priv_init failed, err=-12
mlx5_core 0012:03:00.1 gpu3rdma1: mlx5e_netdev_change_profile: new profile init failed, -12
workqueue: Failed to create a rescuer kthread for wq "mlx5e": -EINTR
mlx5_core 0012:03:00.1: mlx5e_netdev_init_profile:6214:(pid 37199): mlx5e_priv_init failed, err=-12
mlx5_core 0012:03:00.1 gpu3rdma1: mlx5e_netdev_change_profile: failed to rollback to orig profile, -12
^^^^^^^^
mlx5_core 0000:00:03.0: E-Switch: Disable: mode(LEGACY), nvfs(0), necvfs(0), active vports(0)
## retry: Enabling switchdev mode 2nd time:
mlx5_core 0000:00:03.0: E-Switch: Supported tc chains and prios offload
BUG: kernel NULL pointer dereference, address: 0000000000000038
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP NOPTI
CPU: 13 UID: 0 PID: 520 Comm: devlink Not tainted 6.18.0-rc4+ #91 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014
RIP: 0010:mlx5e_detach_netdev+0x3c/0x90
Code: 50 00 00 f0 80 4f 78 02 48 8b bf e8 07 00 00 48 85 ff 74 16 48 8b 73 78 48 d1 ee 83 e6 01 83 f6 01 40 0f b6 f6 e8 c4 42 00 00 <48> 8b 45 38 48 85 c0 74 08 48 89 df e8 cc 47 40 1e 48 8b bb f0 07
RSP: 0018:ffffc90000673890 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8881036a89c0 RCX: 0000000000000000
RDX: ffff888113f63800 RSI: ffffffff822fe720 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000002dcd R09: 0000000000000000
R10: ffffc900006738e8 R11: 00000000ffffffff R12: 0000000000000000
R13: 0000000000000000 R14: ffff8881036a89c0 R15: 0000000000000000
FS: 00007fdfb8384740(0000) GS:ffff88856a9d6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000038 CR3: 0000000112ae0005 CR4: 0000000000370ef0
Call Trace:
<TASK>
mlx5e_netdev_change_profile+0x45/0xb0
mlx5e_vport_rep_load+0x27b/0x2d0
mlx5_esw_offloads_rep_load+0x72/0xf0
esw_offloads_enable+0x5d0/0x970
mlx5_eswitch_enable_locked+0x349/0x430
? is_mp_supported+0x57/0xb0
mlx5_devlink_eswitch_mode_set+0x26b/0x430
devlink_nl_eswitch_set_doit+0x6f/0xf0
genl_family_rcv_msg_doit+0xe8/0x140
genl_rcv_msg+0x18b/0x290
? __pfx_devlink_nl_pre_doit+0x10/0x10
? __pfx_devlink_nl_eswitch_set_doit+0x10/0x10
? __pfx_devlink_nl_post_doit+0x10/0x10
? __pfx_genl_rcv_msg+0x10/0x10
netlink_rcv_skb+0x52/0x100
genl_rcv+0x28/0x40
netlink_unicast+0x282/0x3e0
? __alloc_skb+0xd6/0x190
netlink_sendmsg+0x1f7/0x430
__sys_sendto+0x213/0x220
? __sys_recvmsg+0x6a/0xd0
__x64_sys_sendto+0x24/0x30
do_syscall_64+0x50/0x1f0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fdfb8495047
In the Linux kernel, the following vulnerability has been resolved:
macvlan: fix possible UAF in macvlan_forward_source()
Add RCU protection on (struct macvlan_source_entry)->vlan.
Whenever macvlan_hash_del_source() is called, we must clear
entry->vlan pointer before RCU grace period starts.
This allows macvlan_forward_source() to skip over
entries queued for freeing.
Note that macvlan_dev are already RCU protected, as they
are embedded in a standard netdev (netdev_priv(ndev)).
https: //lore.kernel.org/netdev/695fb1e8.050a0220.1c677c.039f.GAE@google.com/T/#u
In the Linux kernel, the following vulnerability has been resolved:
dmaengine: tegra-adma: Fix use-after-free
A use-after-free bug exists in the Tegra ADMA driver when audio streams
are terminated, particularly during XRUN conditions. The issue occurs
when the DMA buffer is freed by tegra_adma_terminate_all() before the
vchan completion tasklet finishes accessing it.
The race condition follows this sequence:
1. DMA transfer completes, triggering an interrupt that schedules the
completion tasklet (tasklet has not executed yet)
2. Audio playback stops, calling tegra_adma_terminate_all() which
frees the DMA buffer memory via kfree()
3. The scheduled tasklet finally executes, calling vchan_complete()
which attempts to access the already-freed memory
Since tasklets can execute at any time after being scheduled, there is
no guarantee that the buffer will remain valid when vchan_complete()
runs.
Fix this by properly synchronizing the virtual channel completion:
- Calling vchan_terminate_vdesc() in tegra_adma_stop() to mark the
descriptors as terminated instead of freeing the descriptor.
- Add the callback tegra_adma_synchronize() that calls
vchan_synchronize() which kills any pending tasklets and frees any
terminated descriptors.
Crash logs:
[ 337.427523] BUG: KASAN: use-after-free in vchan_complete+0x124/0x3b0
[ 337.427544] Read of size 8 at addr ffff000132055428 by task swapper/0/0
[ 337.427562] Call trace:
[ 337.427564] dump_backtrace+0x0/0x320
[ 337.427571] show_stack+0x20/0x30
[ 337.427575] dump_stack_lvl+0x68/0x84
[ 337.427584] print_address_description.constprop.0+0x74/0x2b8
[ 337.427590] kasan_report+0x1f4/0x210
[ 337.427598] __asan_load8+0xa0/0xd0
[ 337.427603] vchan_complete+0x124/0x3b0
[ 337.427609] tasklet_action_common.constprop.0+0x190/0x1d0
[ 337.427617] tasklet_action+0x30/0x40
[ 337.427623] __do_softirq+0x1a0/0x5c4
[ 337.427628] irq_exit+0x110/0x140
[ 337.427633] handle_domain_irq+0xa4/0xe0
[ 337.427640] gic_handle_irq+0x64/0x160
[ 337.427644] call_on_irq_stack+0x20/0x4c
[ 337.427649] do_interrupt_handler+0x7c/0x90
[ 337.427654] el1_interrupt+0x30/0x80
[ 337.427659] el1h_64_irq_handler+0x18/0x30
[ 337.427663] el1h_64_irq+0x7c/0x80
[ 337.427667] cpuidle_enter_state+0xe4/0x540
[ 337.427674] cpuidle_enter+0x54/0x80
[ 337.427679] do_idle+0x2e0/0x380
[ 337.427685] cpu_startup_entry+0x2c/0x70
[ 337.427690] rest_init+0x114/0x130
[ 337.427695] arch_call_rest_init+0x18/0x24
[ 337.427702] start_kernel+0x380/0x3b4
[ 337.427706] __primary_switched+0xc0/0xc8