Security Vulnerabilities - CVEs Published In November 2024
In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Unregister redistributor for failed vCPU creation
Alex reports that syzkaller has managed to trigger a use-after-free when
tearing down a VM:
BUG: KASAN: slab-use-after-free in kvm_put_kvm+0x300/0xe68 virt/kvm/kvm_main.c:5769
Read of size 8 at addr ffffff801c6890d0 by task syz.3.2219/10758
CPU: 3 UID: 0 PID: 10758 Comm: syz.3.2219 Not tainted 6.11.0-rc6-dirty #64
Hardware name: linux,dummy-virt (DT)
Call trace:
dump_backtrace+0x17c/0x1a8 arch/arm64/kernel/stacktrace.c:317
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:324
__dump_stack lib/dump_stack.c:93 [inline]
dump_stack_lvl+0x94/0xc0 lib/dump_stack.c:119
print_report+0x144/0x7a4 mm/kasan/report.c:377
kasan_report+0xcc/0x128 mm/kasan/report.c:601
__asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381
kvm_put_kvm+0x300/0xe68 virt/kvm/kvm_main.c:5769
kvm_vm_release+0x4c/0x60 virt/kvm/kvm_main.c:1409
__fput+0x198/0x71c fs/file_table.c:422
____fput+0x20/0x30 fs/file_table.c:450
task_work_run+0x1cc/0x23c kernel/task_work.c:228
do_notify_resume+0x144/0x1a0 include/linux/resume_user_mode.h:50
el0_svc+0x64/0x68 arch/arm64/kernel/entry-common.c:169
el0t_64_sync_handler+0x90/0xfc arch/arm64/kernel/entry-common.c:730
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598
Upon closer inspection, it appears that we do not properly tear down the
MMIO registration for a vCPU that fails creation late in the game, e.g.
a vCPU w/ the same ID already exists in the VM.
It is important to consider the context of commit that introduced this bug
by moving the unregistration out of __kvm_vgic_vcpu_destroy(). That
change correctly sought to avoid an srcu v. config_lock inversion by
breaking up the vCPU teardown into two parts, one guarded by the
config_lock.
Fix the use-after-free while avoiding lock inversion by adding a
special-cased unregistration to __kvm_vgic_vcpu_destroy(). This is safe
because failed vCPUs are torn down outside of the config_lock.
CVSS Score
7.8
EPSS Score
0.002
Published
2024-11-05
In the Linux kernel, the following vulnerability has been resolved:
KVM: nSVM: Ignore nCR3[4:0] when loading PDPTEs from memory
Ignore nCR3[4:0] when loading PDPTEs from memory for nested SVM, as bits
4:0 of CR3 are ignored when PAE paging is used, and thus VMRUN doesn't
enforce 32-byte alignment of nCR3.
In the absolute worst case scenario, failure to ignore bits 4:0 can result
in an out-of-bounds read, e.g. if the target page is at the end of a
memslot, and the VMM isn't using guard pages.
Per the APM:
The CR3 register points to the base address of the page-directory-pointer
table. The page-directory-pointer table is aligned on a 32-byte boundary,
with the low 5 address bits 4:0 assumed to be 0.
And the SDM's much more explicit:
4:0 Ignored
Note, KVM gets this right when loading PDPTRs, it's only the nSVM flow
that is broken.
CVSS Score
8.4
EPSS Score
0.002
Published
2024-11-05
In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix kernel bug due to missing clearing of buffer delay flag
Syzbot reported that after nilfs2 reads a corrupted file system image
and degrades to read-only, the BUG_ON check for the buffer delay flag
in submit_bh_wbc() may fail, causing a kernel bug.
This is because the buffer delay flag is not cleared when clearing the
buffer state flags to discard a page/folio or a buffer head. So, fix
this.
This became necessary when the use of nilfs2's own page clear routine
was expanded. This state inconsistency does not occur if the buffer
is written normally by log writing.
CVSS Score
5.5
EPSS Score
0.002
Published
2024-11-05
In the Linux kernel, the following vulnerability has been resolved:
drm/amd: Guard against bad data for ATIF ACPI method
If a BIOS provides bad data in response to an ATIF method call
this causes a NULL pointer dereference in the caller.
```
? show_regs (arch/x86/kernel/dumpstack.c:478 (discriminator 1))
? __die (arch/x86/kernel/dumpstack.c:423 arch/x86/kernel/dumpstack.c:434)
? page_fault_oops (arch/x86/mm/fault.c:544 (discriminator 2) arch/x86/mm/fault.c:705 (discriminator 2))
? do_user_addr_fault (arch/x86/mm/fault.c:440 (discriminator 1) arch/x86/mm/fault.c:1232 (discriminator 1))
? acpi_ut_update_object_reference (drivers/acpi/acpica/utdelete.c:642)
? exc_page_fault (arch/x86/mm/fault.c:1542)
? asm_exc_page_fault (./arch/x86/include/asm/idtentry.h:623)
? amdgpu_atif_query_backlight_caps.constprop.0 (drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c:387 (discriminator 2)) amdgpu
? amdgpu_atif_query_backlight_caps.constprop.0 (drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c:386 (discriminator 1)) amdgpu
```
It has been encountered on at least one system, so guard for it.
(cherry picked from commit c9b7c809b89f24e9372a4e7f02d64c950b07fdee)
CVSS Score
7.3
EPSS Score
0.003
Published
2024-11-05
In the Linux kernel, the following vulnerability has been resolved:
btrfs: reject ro->rw reconfiguration if there are hard ro requirements
[BUG]
Syzbot reports the following crash:
BTRFS info (device loop0 state MCS): disabling free space tree
BTRFS info (device loop0 state MCS): clearing compat-ro feature flag for FREE_SPACE_TREE (0x1)
BTRFS info (device loop0 state MCS): clearing compat-ro feature flag for FREE_SPACE_TREE_VALID (0x2)
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:backup_super_roots fs/btrfs/disk-io.c:1691 [inline]
RIP: 0010:write_all_supers+0x97a/0x40f0 fs/btrfs/disk-io.c:4041
Call Trace:
<TASK>
btrfs_commit_transaction+0x1eae/0x3740 fs/btrfs/transaction.c:2530
btrfs_delete_free_space_tree+0x383/0x730 fs/btrfs/free-space-tree.c:1312
btrfs_start_pre_rw_mount+0xf28/0x1300 fs/btrfs/disk-io.c:3012
btrfs_remount_rw fs/btrfs/super.c:1309 [inline]
btrfs_reconfigure+0xae6/0x2d40 fs/btrfs/super.c:1534
btrfs_reconfigure_for_mount fs/btrfs/super.c:2020 [inline]
btrfs_get_tree_subvol fs/btrfs/super.c:2079 [inline]
btrfs_get_tree+0x918/0x1920 fs/btrfs/super.c:2115
vfs_get_tree+0x90/0x2b0 fs/super.c:1800
do_new_mount+0x2be/0xb40 fs/namespace.c:3472
do_mount fs/namespace.c:3812 [inline]
__do_sys_mount fs/namespace.c:4020 [inline]
__se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3997
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
[CAUSE]
To support mounting different subvolume with different RO/RW flags for
the new mount APIs, btrfs introduced two workaround to support this feature:
- Skip mount option/feature checks if we are mounting a different
subvolume
- Reconfigure the fs to RW if the initial mount is RO
Combining these two, we can have the following sequence:
- Mount the fs ro,rescue=all,clear_cache,space_cache=v1
rescue=all will mark the fs as hard read-only, so no v2 cache clearing
will happen.
- Mount a subvolume rw of the same fs.
We go into btrfs_get_tree_subvol(), but fc_mount() returns EBUSY
because our new fc is RW, different from the original fs.
Now we enter btrfs_reconfigure_for_mount(), which switches the RO flag
first so that we can grab the existing fs_info.
Then we reconfigure the fs to RW.
- During reconfiguration, option/features check is skipped
This means we will restart the v2 cache clearing, and convert back to
v1 cache.
This will trigger fs writes, and since the original fs has "rescue=all"
option, it skips the csum tree read.
And eventually causing NULL pointer dereference in super block
writeback.
[FIX]
For reconfiguration caused by different subvolume RO/RW flags, ensure we
always run btrfs_check_options() to ensure we have proper hard RO
requirements met.
In fact the function btrfs_check_options() doesn't really do many
complex checks, but hard RO requirement and some feature dependency
checks, thus there is no special reason not to do the check for mount
reconfiguration.
CVSS Score
5.5
EPSS Score
0.002
Published
2024-11-05
In the Linux kernel, the following vulnerability has been resolved:
cifs: fix warning when destroy 'cifs_io_request_pool'
There's a issue as follows:
WARNING: CPU: 1 PID: 27826 at mm/slub.c:4698 free_large_kmalloc+0xac/0xe0
RIP: 0010:free_large_kmalloc+0xac/0xe0
Call Trace:
<TASK>
? __warn+0xea/0x330
mempool_destroy+0x13f/0x1d0
init_cifs+0xa50/0xff0 [cifs]
do_one_initcall+0xdc/0x550
do_init_module+0x22d/0x6b0
load_module+0x4e96/0x5ff0
init_module_from_file+0xcd/0x130
idempotent_init_module+0x330/0x620
__x64_sys_finit_module+0xb3/0x110
do_syscall_64+0xc1/0x1d0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Obviously, 'cifs_io_request_pool' is not created by mempool_create().
So just use mempool_exit() to revert 'cifs_io_request_pool'.
CVSS Score
7.0
EPSS Score
0.002
Published
2024-11-05
In the Linux kernel, the following vulnerability has been resolved:
scsi: ufs: core: Set SDEV_OFFLINE when UFS is shut down
There is a history of deadlock if reboot is performed at the beginning
of booting. SDEV_QUIESCE was set for all LU's scsi_devices by UFS
shutdown, and at that time the audio driver was waiting on
blk_mq_submit_bio() holding a mutex_lock while reading the fw binary.
After that, a deadlock issue occurred while audio driver shutdown was
waiting for mutex_unlock of blk_mq_submit_bio(). To solve this, set
SDEV_OFFLINE for all LUs except WLUN, so that any I/O that comes down
after a UFS shutdown will return an error.
[ 31.907781]I[0: swapper/0: 0] 1 130705007 1651079834 11289729804 0 D( 2) 3 ffffff882e208000 * init [device_shutdown]
[ 31.907793]I[0: swapper/0: 0] Mutex: 0xffffff8849a2b8b0: owner[0xffffff882e28cb00 kworker/6:0 :49]
[ 31.907806]I[0: swapper/0: 0] Call trace:
[ 31.907810]I[0: swapper/0: 0] __switch_to+0x174/0x338
[ 31.907819]I[0: swapper/0: 0] __schedule+0x5ec/0x9cc
[ 31.907826]I[0: swapper/0: 0] schedule+0x7c/0xe8
[ 31.907834]I[0: swapper/0: 0] schedule_preempt_disabled+0x24/0x40
[ 31.907842]I[0: swapper/0: 0] __mutex_lock+0x408/0xdac
[ 31.907849]I[0: swapper/0: 0] __mutex_lock_slowpath+0x14/0x24
[ 31.907858]I[0: swapper/0: 0] mutex_lock+0x40/0xec
[ 31.907866]I[0: swapper/0: 0] device_shutdown+0x108/0x280
[ 31.907875]I[0: swapper/0: 0] kernel_restart+0x4c/0x11c
[ 31.907883]I[0: swapper/0: 0] __arm64_sys_reboot+0x15c/0x280
[ 31.907890]I[0: swapper/0: 0] invoke_syscall+0x70/0x158
[ 31.907899]I[0: swapper/0: 0] el0_svc_common+0xb4/0xf4
[ 31.907909]I[0: swapper/0: 0] do_el0_svc+0x2c/0xb0
[ 31.907918]I[0: swapper/0: 0] el0_svc+0x34/0xe0
[ 31.907928]I[0: swapper/0: 0] el0t_64_sync_handler+0x68/0xb4
[ 31.907937]I[0: swapper/0: 0] el0t_64_sync+0x1a0/0x1a4
[ 31.908774]I[0: swapper/0: 0] 49 0 11960702 11236868007 0 D( 2) 6 ffffff882e28cb00 * kworker/6:0 [__bio_queue_enter]
[ 31.908783]I[0: swapper/0: 0] Call trace:
[ 31.908788]I[0: swapper/0: 0] __switch_to+0x174/0x338
[ 31.908796]I[0: swapper/0: 0] __schedule+0x5ec/0x9cc
[ 31.908803]I[0: swapper/0: 0] schedule+0x7c/0xe8
[ 31.908811]I[0: swapper/0: 0] __bio_queue_enter+0xb8/0x178
[ 31.908818]I[0: swapper/0: 0] blk_mq_submit_bio+0x194/0x67c
[ 31.908827]I[0: swapper/0: 0] __submit_bio+0xb8/0x19c
CVSS Score
5.5
EPSS Score
0.002
Published
2024-11-05
In the Linux kernel, the following vulnerability has been resolved:
arm64: probes: Remove broken LDR (literal) uprobe support
The simulate_ldr_literal() and simulate_ldrsw_literal() functions are
unsafe to use for uprobes. Both functions were originally written for
use with kprobes, and access memory with plain C accesses. When uprobes
was added, these were reused unmodified even though they cannot safely
access user memory.
There are three key problems:
1) The plain C accesses do not have corresponding extable entries, and
thus if they encounter a fault the kernel will treat these as
unintentional accesses to user memory, resulting in a BUG() which
will kill the kernel thread, and likely lead to further issues (e.g.
lockup or panic()).
2) The plain C accesses are subject to HW PAN and SW PAN, and so when
either is in use, any attempt to simulate an access to user memory
will fault. Thus neither simulate_ldr_literal() nor
simulate_ldrsw_literal() can do anything useful when simulating a
user instruction on any system with HW PAN or SW PAN.
3) The plain C accesses are privileged, as they run in kernel context,
and in practice can access a small range of kernel virtual addresses.
The instructions they simulate have a range of +/-1MiB, and since the
simulated instructions must itself be a user instructions in the
TTBR0 address range, these can address the final 1MiB of the TTBR1
acddress range by wrapping downwards from an address in the first
1MiB of the TTBR0 address range.
In contemporary kernels the last 8MiB of TTBR1 address range is
reserved, and accesses to this will always fault, meaning this is no
worse than (1).
Historically, it was theoretically possible for the linear map or
vmemmap to spill into the final 8MiB of the TTBR1 address range, but
in practice this is extremely unlikely to occur as this would
require either:
* Having enough physical memory to fill the entire linear map all the
way to the final 1MiB of the TTBR1 address range.
* Getting unlucky with KASLR randomization of the linear map such
that the populated region happens to overlap with the last 1MiB of
the TTBR address range.
... and in either case if we were to spill into the final page there
would be larger problems as the final page would alias with error
pointers.
Practically speaking, (1) and (2) are the big issues. Given there have
been no reports of problems since the broken code was introduced, it
appears that no-one is relying on probing these instructions with
uprobes.
Avoid these issues by not allowing uprobes on LDR (literal) and LDRSW
(literal), limiting the use of simulate_ldr_literal() and
simulate_ldrsw_literal() to kprobes. Attempts to place uprobes on LDR
(literal) and LDRSW (literal) will be rejected as
arm_probe_decode_insn() will return INSN_REJECTED. In future we can
consider introducing working uprobes support for these instructions, but
this will require more significant work.
CVSS Score
7.3
EPSS Score
0.003
Published
2024-11-05
In the Linux kernel, the following vulnerability has been resolved:
USB: gadget: dummy-hcd: Fix "task hung" problem
The syzbot fuzzer has been encountering "task hung" problems ever
since the dummy-hcd driver was changed to use hrtimers instead of
regular timers. It turns out that the problems are caused by a subtle
difference between the timer_pending() and hrtimer_active() APIs.
The changeover blindly replaced the first by the second. However,
timer_pending() returns True when the timer is queued but not when its
callback is running, whereas hrtimer_active() returns True when the
hrtimer is queued _or_ its callback is running. This difference
occasionally caused dummy_urb_enqueue() to think that the callback
routine had not yet started when in fact it was almost finished. As a
result the hrtimer was not restarted, which made it impossible for the
driver to dequeue later the URB that was just enqueued. This caused
usb_kill_urb() to hang, and things got worse from there.
Since hrtimers have no API for telling when they are queued and the
callback isn't running, the driver must keep track of this for itself.
That's what this patch does, adding a new "timer_pending" flag and
setting or clearing it at the appropriate times.
CVSS Score
5.5
EPSS Score
0.002
Published
2024-11-05
In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Fix incorrect pci_for_each_dma_alias() for non-PCI devices
Previously, the domain_context_clear() function incorrectly called
pci_for_each_dma_alias() to set up context entries for non-PCI devices.
This could lead to kernel hangs or other unexpected behavior.
Add a check to only call pci_for_each_dma_alias() for PCI devices. For
non-PCI devices, domain_context_clear_one() is called directly.
CVSS Score
7.8
EPSS Score
0.002
Published
2024-11-05