In the Linux kernel, the following vulnerability has been resolved:
selinux: fix overlayfs mmap() and mprotect() access checks
The existing SELinux security model for overlayfs is to allow access if
the current task is able to access the top level file (the "user" file)
and the mounter's credentials are sufficient to access the lower
level file (the "backing" file). Unfortunately, the current code does
not properly enforce these access controls for both mmap() and mprotect()
operations on overlayfs filesystems.
This patch makes use of the newly created security_mmap_backing_file()
LSM hook to provide the missing backing file enforcement for mmap()
operations, and leverages the backing file API and new LSM blob to
provide the necessary information to properly enforce the mprotect()
access controls.
In the Linux kernel, the following vulnerability has been resolved:
KVM: nSVM: Always use NextRIP as vmcb02's NextRIP after first L2 VMRUN
For guests with NRIPS disabled, L1 does not provide NextRIP when running
an L2 with an injected soft interrupt, instead it advances the current RIP
before running it. KVM uses the current RIP as the NextRIP in vmcb02 to
emulate a CPU without NRIPS.
However, after L2 runs the first time, NextRIP will be updated by the CPU
and/or KVM, and the current RIP is no longer the correct value to use in
vmcb02. Hence, after save/restore, use the current RIP if and only if a
nested run is pending, otherwise use NextRIP. Give soft_int_next_rip the
same treatment, as it's the same logic, just for a narrower use case.
[sean: give soft_int_next_rip the same treatment]
In the Linux kernel, the following vulnerability has been resolved:
ipmi:ssif: Clean up kthread on errors
If an error occurs after the ssif kthread is created, but before the
main IPMI code starts the ssif interface, the ssif kthread will not
be stopped.
So make sure the kthread is stopped on an error condition if it is
running.
In the Linux kernel, the following vulnerability has been resolved:
KVM: nSVM: Triple fault if restore host CR3 fails on nested #VMEXIT
If loading L1's CR3 fails on a nested #VMEXIT, nested_svm_vmexit()
returns an error code that is ignored by most callers, and continues to
run L1 with corrupted state. A sane recovery is not possible in this
case, and HW behavior is to cause a shutdown. Inject a triple fault
instead, and do not return early from nested_svm_vmexit(). Continue
cleaning up the vCPU state (e.g. clear pending exceptions), to handle
the failure as gracefully as possible.
From the APM:
Upon #VMEXIT, the processor performs the following actions in order to
return to the host execution context:
...
if (illegal host state loaded, or exception while loading host state)
shutdown
else
execute first host instruction following the VMRUN
Remove the return value of nested_svm_vmexit(), which is mostly
unchecked anyway.
In the Linux kernel, the following vulnerability has been resolved:
mm: fix deferred split queue races during migration
migrate_folio_move() records the deferred split queue state from src and
replays it on dst. Replaying it after remove_migration_ptes(src, dst, 0)
makes dst visible before it is requeued, so a concurrent rmap-removal path
can mark dst partially mapped and trip the WARN in deferred_split_folio().
Move the requeue before remove_migration_ptes() so dst is back on the
deferred split queue before it becomes visible again.
Because migration still holds dst locked at that point, teach
deferred_split_scan() to requeue a folio when folio_trylock() fails.
Otherwise a fully mapped underused folio can be dequeued by the shrinker
and silently lost from split_queue.
[ziy@nvidia.com: move the comment]
In the Linux kernel, the following vulnerability has been resolved:
KVM: SVM: Add missing save/restore handling of LBR MSRs
MSR_IA32_DEBUGCTLMSR and LBR MSRs are currently not enumerated by
KVM_GET_MSR_INDEX_LIST, and LBR MSRs cannot be set with KVM_SET_MSRS. So
save/restore is completely broken.
Fix it by adding the MSRs to msrs_to_save_base, and allowing writes to
LBR MSRs from userspace only (as they are read-only MSRs) if LBR
virtualization is enabled. Additionally, to correctly restore L1's LBRs
while L2 is running, make sure the LBRs are copied from the captured
VMCB01 save area in svm_copy_vmrun_state().
Note, for VMX, this also fixes a flaw where MSR_IA32_DEBUGCTLMSR isn't
reported as an MSR to save/restore.
Note #2, over-reporting MSR_IA32_LASTxxx on Intel is ok, as KVM already
handles unsupported reads and writes thanks to commit b5e2fec0ebc3 ("KVM:
Ignore DEBUGCTL MSRs with no effect") (kvm_do_msr_access() will morph the
unsupported userspace write into a nop).
[sean: guard with lbrv checks, massage changelog]
In the Linux kernel, the following vulnerability has been resolved:
ASoC: nau8821: Cancel delayed work on component remove
Attempting to unload the driver while a jack detection work is pending
would likely crash the kernel when it is eventually scheduled for
execution:
[ 1984.896308] BUG: unable to handle page fault for address: ffffffffc10c2a20
[...]
[ 1984.896388] Hardware name: Valve Jupiter/Jupiter, BIOS F7A0131 01/30/2024
[ 1984.896396] Workqueue: events nau8821_jdet_work [snd_soc_nau8821]
[ 1984.896414] RIP: 0010:__mutex_lock+0x9f/0x11d0
[...]
[ 1984.896504] Call Trace:
[ 1984.896511] <TASK>
[ 1984.896524] ? snd_soc_dapm_disable_pin+0x26/0x60 [snd_soc_core]
[ 1984.896572] ? snd_soc_dapm_disable_pin+0x26/0x60 [snd_soc_core]
[ 1984.896596] snd_soc_dapm_disable_pin+0x26/0x60 [snd_soc_core]
[ 1984.896622] nau8821_jdet_work+0xeb/0x1e0 [snd_soc_nau8821]
[ 1984.896636] process_one_work+0x211/0x590
[ 1984.896649] ? srso_return_thunk+0x5/0x5f
[ 1984.896670] worker_thread+0x1cd/0x3a0
Cancel unscheduled jdet_work or wait for its execution to finish before
the component driver gets removed.
In the Linux kernel, the following vulnerability has been resolved:
drm/exynos: vidi: use priv->vidi_dev for ctx lookup in vidi_connection_ioctl()
vidi_connection_ioctl() retrieves the driver_data from drm_dev->dev to
obtain a struct vidi_context pointer. However, drm_dev->dev is the
exynos-drm master device, and the driver_data contained therein is not
the vidi component device, but a completely different device.
This can lead to various bugs, ranging from null pointer dereferences and
garbage value accesses to, in unlucky cases, out-of-bounds errors,
use-after-free errors, and more.
To resolve this issue, we need to store/delete the vidi device pointer in
exynos_drm_private->vidi_dev during bind/unbind, and then read this
exynos_drm_private->vidi_dev within ioctl() to obtain the correct
struct vidi_context pointer.
In the Linux kernel, the following vulnerability has been resolved:
gfs2: fix memory leaks in gfs2_fill_super error path
Fix two memory leaks in the gfs2_fill_super() error handling path when
transitioning a filesystem to read-write mode fails.
First leak: kthread objects (thread_struct, task_struct, etc.)
When gfs2_freeze_lock_shared() fails after init_threads() succeeds, the
created kernel threads (logd and quotad) are never destroyed. This
occurs because the fail_per_node label doesn't call
gfs2_destroy_threads().
Second leak: quota bitmap buffer (8192 bytes)
When gfs2_make_fs_rw() fails after gfs2_quota_init() succeeds but
before other operations complete, the allocated quota bitmap is never
freed.
The fix moves thread cleanup to the fail_per_node label to handle all
error paths uniformly. gfs2_destroy_threads() is safe to call
unconditionally as it checks for NULL pointers. Quota cleanup is added
in gfs2_make_fs_rw() to properly handle the withdrawal case where
quota initialization succeeds but the filesystem is then withdrawn.
Thread leak backtrace (gfs2_freeze_lock_shared failure):
unreferenced object 0xffff88801d7bca80 (size 4480):
copy_process+0x3a1/0x4670 kernel/fork.c:2422
kernel_clone+0xf3/0x6e0 kernel/fork.c:2779
kthread_create_on_node+0x100/0x150 kernel/kthread.c:478
init_threads+0xab/0x350 fs/gfs2/ops_fstype.c:611
gfs2_fill_super+0xe5c/0x1240 fs/gfs2/ops_fstype.c:1265
Quota leak backtrace (gfs2_make_fs_rw failure):
unreferenced object 0xffff88812de7c000 (size 8192):
gfs2_quota_init+0xe5/0x820 fs/gfs2/quota.c:1409
gfs2_make_fs_rw+0x7a/0xe0 fs/gfs2/super.c:149
gfs2_fill_super+0xfbb/0x1240 fs/gfs2/ops_fstype.c:1275
In the Linux kernel, the following vulnerability has been resolved:
net: stmmac: fix oops when split header is enabled
For GMAC4, when split header is enabled, in some rare cases, the
hardware does not fill buf2 of the first descriptor with payload.
Thus we cannot assume buf2 is always fully filled if it is not
the last descriptor. Otherwise, the length of buf2 of the second
descriptor will be calculated wrong and cause an oops:
Unable to handle kernel paging request at virtual address ffff00019246bfc0
...
x2 : 0000000000000040 x1 : ffff00019246bfc0 x0 : ffff00009246c000
Call trace:
dcache_inval_poc+0x28/0x58 (P)
dma_direct_sync_single_for_cpu+0x38/0x6c
__dma_sync_single_for_cpu+0x34/0x6c
stmmac_napi_poll_rx+0x8f0/0xb60
__napi_poll.constprop.0+0x30/0x144
net_rx_action+0x160/0x274
handle_softirqs+0x1b8/0x1fc
...
To fix this, the PL bit-field in RDES3 register is used for all
descriptors, whether it is the last descriptor or not.