Linux: >> Linux Kernel >> 6.1.49 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
LoongArch: Enable IRQ if do_ale() triggered in irq-enabled context
Unaligned access exception can be triggered in irq-enabled context such
as user mode, in this case do_ale() may call get_user() which may cause
sleep. Then we will get:
BUG: sleeping function called from invalid context at arch/loongarch/kernel/access-helper.h:7
in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 129, name: modprobe
preempt_count: 0, expected: 0
RCU nest depth: 0, expected: 0
CPU: 0 UID: 0 PID: 129 Comm: modprobe Tainted: G W 6.12.0-rc1+ #1723
Tainted: [W]=WARN
Stack : 9000000105e0bd48 0000000000000000 9000000003803944 9000000105e08000
9000000105e0bc70 9000000105e0bc78 0000000000000000 0000000000000000
9000000105e0bc78 0000000000000001 9000000185e0ba07 9000000105e0b890
ffffffffffffffff 9000000105e0bc78 73924b81763be05b 9000000100194500
000000000000020c 000000000000000a 0000000000000000 0000000000000003
00000000000023f0 00000000000e1401 00000000072f8000 0000007ffbb0e260
0000000000000000 0000000000000000 9000000005437650 90000000055d5000
0000000000000000 0000000000000003 0000007ffbb0e1f0 0000000000000000
0000005567b00490 0000000000000000 9000000003803964 0000007ffbb0dfec
00000000000000b0 0000000000000007 0000000000000003 0000000000071c1d
...
Call Trace:
[<9000000003803964>] show_stack+0x64/0x1a0
[<9000000004c57464>] dump_stack_lvl+0x74/0xb0
[<9000000003861ab4>] __might_resched+0x154/0x1a0
[<900000000380c96c>] emulate_load_store_insn+0x6c/0xf60
[<9000000004c58118>] do_ale+0x78/0x180
[<9000000003801bc8>] handle_ale+0x128/0x1e0
So enable IRQ if unaligned access exception is triggered in irq-enabled
context to fix it.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-11-05
In the Linux kernel, the following vulnerability has been resolved:
x86/lam: Disable ADDRESS_MASKING in most cases
Linear Address Masking (LAM) has a weakness related to transient
execution as described in the SLAM paper[1]. Unless Linear Address
Space Separation (LASS) is enabled this weakness may be exploitable.
Until kernel adds support for LASS[2], only allow LAM for COMPILE_TEST,
or when speculation mitigations have been disabled at compile time,
otherwise keep LAM disabled.
There are no processors in market that support LAM yet, so currently
nobody is affected by this issue.
[1] SLAM: https://download.vusec.net/papers/slam_sp24.pdf
[2] LASS: https://lore.kernel.org/lkml/20230609183632.48706-1-alexander.shishkin@linux.intel.com/
[ dhansen: update SPECULATION_MITIGATIONS -> CPU_MITIGATIONS ]
CVSS Score
7.8
EPSS Score
0.0
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
7.1
EPSS Score
0.0
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
0.0
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
5.5
EPSS Score
0.0
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
0.0
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
5.5
EPSS Score
0.0
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
5.5
EPSS Score
0.0
Published
2024-11-05
In the Linux kernel, the following vulnerability has been resolved:
ASoC: qcom: Fix NULL Dereference in asoc_qcom_lpass_cpu_platform_probe()
A devm_kzalloc() in asoc_qcom_lpass_cpu_platform_probe() could
possibly return NULL pointer. NULL Pointer Dereference may be
triggerred without addtional check.
Add a NULL check for the returned pointer.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-11-05
In the Linux kernel, the following vulnerability has been resolved:
drm/xe/oa: Fix overflow in oa batch buffer
By default xe_bb_create_job() appends a MI_BATCH_BUFFER_END to batch
buffer, this is not a problem if batch buffer is only used once but
oa reuses the batch buffer for the same metric and at each call
it appends a MI_BATCH_BUFFER_END, printing the warning below and then
overflowing.
[ 381.072016] ------------[ cut here ]------------
[ 381.072019] xe 0000:00:02.0: [drm] Assertion `bb->len * 4 + bb_prefetch(q->gt) <= size` failed!
platform: LUNARLAKE subplatform: 1
graphics: Xe2_LPG / Xe2_HPG 20.04 step B0
media: Xe2_LPM / Xe2_HPM 20.00 step B0
tile: 0 VRAM 0 B
GT: 0 type 1
So here checking if batch buffer already have MI_BATCH_BUFFER_END if
not append it.
v2:
- simply fix, suggestion from Ashutosh
(cherry picked from commit 9ba0e0f30ca42a98af3689460063edfb6315718a)
CVSS Score
5.5
EPSS Score
0.0
Published
2024-11-05