Security Vulnerabilities
- CVEs Published In September 2024
In the Linux kernel, the following vulnerability has been resolved:
drm/xe/client: fix deadlock in show_meminfo()
There is a real deadlock as well as sleeping in atomic() bug in here, if
the bo put happens to be the last ref, since bo destruction wants to
grab the same spinlock and sleeping locks. Fix that by dropping the ref
using xe_bo_put_deferred(), and moving the final commit outside of the
lock. Dropping the lock around the put is tricky since the bo can go
out of scope and delete itself from the list, making it difficult to
navigate to the next list entry.
(cherry picked from commit 0083b8e6f11d7662283a267d4ce7c966812ffd8a)
In the Linux kernel, the following vulnerability has been resolved:
btrfs: clean up our handling of refs == 0 in snapshot delete
In reada we BUG_ON(refs == 0), which could be unkind since we aren't
holding a lock on the extent leaf and thus could get a transient
incorrect answer. In walk_down_proc we also BUG_ON(refs == 0), which
could happen if we have extent tree corruption. Change that to return
-EUCLEAN. In do_walk_down() we catch this case and handle it correctly,
however we return -EIO, which -EUCLEAN is a more appropriate error code.
Finally in walk_up_proc we have the same BUG_ON(refs == 0), so convert
that to proper error handling. Also adjust the error message so we can
actually do something with the information.
In the Linux kernel, the following vulnerability has been resolved:
btrfs: don't BUG_ON on ENOMEM from btrfs_lookup_extent_info() in walk_down_proc()
We handle errors here properly, ENOMEM isn't fatal, return the error.
In the Linux kernel, the following vulnerability has been resolved:
scsi: lpfc: Handle mailbox timeouts in lpfc_get_sfp_info
The MBX_TIMEOUT return code is not handled in lpfc_get_sfp_info and the
routine unconditionally frees submitted mailbox commands regardless of
return status. The issue is that for MBX_TIMEOUT cases, when firmware
returns SFP information at a later time, that same mailbox memory region
references previously freed memory in its cmpl routine.
Fix by adding checks for the MBX_TIMEOUT return code. During mailbox
resource cleanup, check the mbox flag to make sure that the wait did not
timeout. If the MBOX_WAKE flag is not set, then do not free the resources
because it will be freed when firmware completes the mailbox at a later
time in its cmpl routine.
Also, increase the timeout from 30 to 60 seconds to accommodate boot
scripts requiring longer timeouts.
In the Linux kernel, the following vulnerability has been resolved:
scsi: ufs: core: Remove SCSI host only if added
If host tries to remove ufshcd driver from a UFS device it would cause a
kernel panic if ufshcd_async_scan fails during ufshcd_probe_hba before
adding a SCSI host with scsi_add_host and MCQ is enabled since SCSI host
has been defered after MCQ configuration introduced by commit 0cab4023ec7b
("scsi: ufs: core: Defer adding host to SCSI if MCQ is supported").
To guarantee that SCSI host is removed only if it has been added, set the
scsi_host_added flag to true after adding a SCSI host and check whether it
is set or not before removing it.
In the Linux kernel, the following vulnerability has been resolved:
um: line: always fill *error_out in setup_one_line()
The pointer isn't initialized by callers, but I have
encountered cases where it's still printed; initialize
it in all possible cases in setup_one_line().
In the Linux kernel, the following vulnerability has been resolved:
tracing/timerlat: Only clear timer if a kthread exists
The timerlat tracer can use user space threads to check for osnoise and
timer latency. If the program using this is killed via a SIGTERM, the
threads are shutdown one at a time and another tracing instance can start
up resetting the threads before they are fully closed. That causes the
hrtimer assigned to the kthread to be shutdown and freed twice when the
dying thread finally closes the file descriptors, causing a use-after-free
bug.
Only cancel the hrtimer if the associated thread is still around. Also add
the interface_lock around the resetting of the tlat_var->kthread.
Note, this is just a quick fix that can be backported to stable. A real
fix is to have a better synchronization between the shutdown of old
threads and the starting of new ones.
In the Linux kernel, the following vulnerability has been resolved:
spi: rockchip: Resolve unbalanced runtime PM / system PM handling
Commit e882575efc77 ("spi: rockchip: Suspend and resume the bus during
NOIRQ_SYSTEM_SLEEP_PM ops") stopped respecting runtime PM status and
simply disabled clocks unconditionally when suspending the system. This
causes problems when the device is already runtime suspended when we go
to sleep -- in which case we double-disable clocks and produce a
WARNing.
Switch back to pm_runtime_force_{suspend,resume}(), because that still
seems like the right thing to do, and the aforementioned commit makes no
explanation why it stopped using it.
Also, refactor some of the resume() error handling, because it's not
actually a good idea to re-disable clocks on failure.
In the Linux kernel, the following vulnerability has been resolved:
mm: vmalloc: ensure vmap_block is initialised before adding to queue
Commit 8c61291fd850 ("mm: fix incorrect vbq reference in
purge_fragmented_block") extended the 'vmap_block' structure to contain a
'cpu' field which is set at allocation time to the id of the initialising
CPU.
When a new 'vmap_block' is being instantiated by new_vmap_block(), the
partially initialised structure is added to the local 'vmap_block_queue'
xarray before the 'cpu' field has been initialised. If another CPU is
concurrently walking the xarray (e.g. via vm_unmap_aliases()), then it
may perform an out-of-bounds access to the remote queue thanks to an
uninitialised index.
This has been observed as UBSAN errors in Android:
| Internal error: UBSAN: array index out of bounds: 00000000f2005512 [#1] PREEMPT SMP
|
| Call trace:
| purge_fragmented_block+0x204/0x21c
| _vm_unmap_aliases+0x170/0x378
| vm_unmap_aliases+0x1c/0x28
| change_memory_common+0x1dc/0x26c
| set_memory_ro+0x18/0x24
| module_enable_ro+0x98/0x238
| do_init_module+0x1b0/0x310
Move the initialisation of 'vb->cpu' in new_vmap_block() ahead of the
addition to the xarray.
In the Linux kernel, the following vulnerability has been resolved:
perf/x86/intel: Limit the period on Haswell
Running the ltp test cve-2015-3290 concurrently reports the following
warnings.
perfevents: irq loop stuck!
WARNING: CPU: 31 PID: 32438 at arch/x86/events/intel/core.c:3174
intel_pmu_handle_irq+0x285/0x370
Call Trace:
<NMI>
? __warn+0xa4/0x220
? intel_pmu_handle_irq+0x285/0x370
? __report_bug+0x123/0x130
? intel_pmu_handle_irq+0x285/0x370
? __report_bug+0x123/0x130
? intel_pmu_handle_irq+0x285/0x370
? report_bug+0x3e/0xa0
? handle_bug+0x3c/0x70
? exc_invalid_op+0x18/0x50
? asm_exc_invalid_op+0x1a/0x20
? irq_work_claim+0x1e/0x40
? intel_pmu_handle_irq+0x285/0x370
perf_event_nmi_handler+0x3d/0x60
nmi_handle+0x104/0x330
Thanks to Thomas Gleixner's analysis, the issue is caused by the low
initial period (1) of the frequency estimation algorithm, which triggers
the defects of the HW, specifically erratum HSW11 and HSW143. (For the
details, please refer https://lore.kernel.org/lkml/87plq9l5d2.ffs@tglx/)
The HSW11 requires a period larger than 100 for the INST_RETIRED.ALL
event, but the initial period in the freq mode is 1. The erratum is the
same as the BDM11, which has been supported in the kernel. A minimum
period of 128 is enforced as well on HSW.
HSW143 is regarding that the fixed counter 1 may overcount 32 with the
Hyper-Threading is enabled. However, based on the test, the hardware
has more issues than it tells. Besides the fixed counter 1, the message
'interrupt took too long' can be observed on any counter which was armed
with a period < 32 and two events expired in the same NMI. A minimum
period of 32 is enforced for the rest of the events.
The recommended workaround code of the HSW143 is not implemented.
Because it only addresses the issue for the fixed counter. It brings
extra overhead through extra MSR writing. No related overcounting issue
has been reported so far.