In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: aspeed: Add NULL pointer check in ast_vhub_init_dev()
The variable d->name, returned by devm_kasprintf(), could be NULL.
A pointer check is added to prevent potential NULL pointer dereference.
This is similar to the fix in commit 3027e7b15b02
("ice: Fix some null pointer dereference issues in ice_ptp.c").
This issue is found by our static analysis tool
In the Linux kernel, the following vulnerability has been resolved:
usb: xhci: Fix isochronous Ring Underrun/Overrun event handling
The TRB pointer of these events points at enqueue at the time of error
occurrence on xHCI 1.1+ HCs or it's NULL on older ones. By the time we
are handling the event, a new TD may be queued at this ring position.
I can trigger this race by rising interrupt moderation to increase IRQ
handling delay. Similar delay may occur naturally due to system load.
If this ever happens after a Missed Service Error, missed TDs will be
skipped and the new TD processed as if it matched the event. It could
be given back prematurely, risking data loss or buffer UAF by the xHC.
Don't complete TDs on xrun events and don't warn if queued TDs don't
match the event's TRB pointer, which can be NULL or a link/no-op TRB.
Don't warn if there are no queued TDs at all.
Now that it's safe, also handle xrun events if the skip flag is clear.
This ensures completion of any TD stuck in 'error mid TD' state right
before the xrun event, which could happen if a driver submits a finite
number of URBs to a buggy HC and then an error occurs on the last TD.
In the Linux kernel, the following vulnerability has been resolved:
s390/sclp: Add check for get_zeroed_page()
Add check for the return value of get_zeroed_page() in
sclp_console_init() to prevent null pointer dereference.
Furthermore, to solve the memory leak caused by the loop
allocation, add a free helper to do the free job.
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix deadlock between rcu_tasks_trace and event_mutex.
Fix the following deadlock:
CPU A
_free_event()
perf_kprobe_destroy()
mutex_lock(&event_mutex)
perf_trace_event_unreg()
synchronize_rcu_tasks_trace()
There are several paths where _free_event() grabs event_mutex
and calls sync_rcu_tasks_trace. Above is one such case.
CPU B
bpf_prog_test_run_syscall()
rcu_read_lock_trace()
bpf_prog_run_pin_on_cpu()
bpf_prog_load()
bpf_tracing_func_proto()
trace_set_clr_event()
mutex_lock(&event_mutex)
Delegate trace_set_clr_event() to workqueue to avoid
such lock dependency.
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Reset IRTE to host control if *new* route isn't postable
Restore an IRTE back to host control (remapped or posted MSI mode) if the
*new* GSI route prevents posting the IRQ directly to a vCPU, regardless of
the GSI routing type. Updating the IRTE if and only if the new GSI is an
MSI results in KVM leaving an IRTE posting to a vCPU.
The dangling IRTE can result in interrupts being incorrectly delivered to
the guest, and in the worst case scenario can result in use-after-free,
e.g. if the VM is torn down, but the underlying host IRQ isn't freed.
In the Linux kernel, the following vulnerability has been resolved:
igc: fix PTM cycle trigger logic
Writing to clear the PTM status 'valid' bit while the PTM cycle is
triggered results in unreliable PTM operation. To fix this, clear the
PTM 'trigger' and status after each PTM transaction.
The issue can be reproduced with the following:
$ sudo phc2sys -R 1000 -O 0 -i tsn0 -m
Note: 1000 Hz (-R 1000) is unrealistically large, but provides a way to
quickly reproduce the issue.
PHC2SYS exits with:
"ioctl PTP_OFFSET_PRECISE: Connection timed out" when the PTM transaction
fails
This patch also fixes a hang in igc_probe() when loading the igc
driver in the kdump kernel on systems supporting PTM.
The igc driver running in the base kernel enables PTM trigger in
igc_probe(). Therefore the driver is always in PTM trigger mode,
except in brief periods when manually triggering a PTM cycle.
When a crash occurs, the NIC is reset while PTM trigger is enabled.
Due to a hardware problem, the NIC is subsequently in a bad busmaster
state and doesn't handle register reads/writes. When running
igc_probe() in the kdump kernel, the first register access to a NIC
register hangs driver probing and ultimately breaks kdump.
With this patch, igc has PTM trigger disabled most of the time,
and the trigger is only enabled for very brief (10 - 100 us) periods
when manually triggering a PTM cycle. Chances that a crash occurs
during a PTM trigger are not 0, but extremely reduced.
In the Linux kernel, the following vulnerability has been resolved:
iommu: Clear iommu-dma ops on cleanup
If iommu_device_register() encounters an error, it can end up tearing
down already-configured groups and default domains, however this
currently still leaves devices hooked up to iommu-dma (and even
historically the behaviour in this area was at best inconsistent across
architectures/drivers...) Although in the case that an IOMMU is present
whose driver has failed to probe, users cannot necessarily expect DMA to
work anyway, it's still arguable that we should do our best to put
things back as if the IOMMU driver was never there at all, and certainly
the potential for crashing in iommu-dma itself is undesirable. Make sure
we clean up the dev->dma_iommu flag along with everything else.
In the Linux kernel, the following vulnerability has been resolved:
scsi: mpi3mr: Synchronous access b/w reset and tm thread for reply queue
When the task management thread processes reply queues while the reset
thread resets them, the task management thread accesses an invalid queue ID
(0xFFFF), set by the reset thread, which points to unallocated memory,
causing a crash.
Add flag 'io_admin_reset_sync' to synchronize access between the reset,
I/O, and admin threads. Before a reset, the reset handler sets this flag to
block I/O and admin processing threads. If any thread bypasses the initial
check, the reset thread waits up to 10 seconds for processing to finish. If
the wait exceeds 10 seconds, the controller is marked as unrecoverable.
In the Linux kernel, the following vulnerability has been resolved:
HID: pidff: Fix null pointer dereference in pidff_find_fields
This function triggered a null pointer dereference if used to search for
a report that isn't implemented on the device. This happened both for
optional and required reports alike.
The same logic was applied to pidff_find_special_field and although
pidff_init_fields should return an error earlier if one of the required
reports is missing, future modifications could change this logic and
resurface this possible null pointer dereference again.
LKML bug report:
https://lore.kernel.org/all/CAL-gK7f5=R0nrrQdPtaZZr1fd-cdAMbDMuZ_NLA8vM0SX+nGSw@mail.gmail.com
In the Linux kernel, the following vulnerability has been resolved:
net: dsa: clean up FDB, MDB, VLAN entries on unbind
As explained in many places such as commit b117e1e8a86d ("net: dsa:
delete dsa_legacy_fdb_add and dsa_legacy_fdb_del"), DSA is written given
the assumption that higher layers have balanced additions/deletions.
As such, it only makes sense to be extremely vocal when those
assumptions are violated and the driver unbinds with entries still
present.
But Ido Schimmel points out a very simple situation where that is wrong:
https://lore.kernel.org/netdev/ZDazSM5UsPPjQuKr@shredder/
(also briefly discussed by me in the aforementioned commit).
Basically, while the bridge bypass operations are not something that DSA
explicitly documents, and for the majority of DSA drivers this API
simply causes them to go to promiscuous mode, that isn't the case for
all drivers. Some have the necessary requirements for bridge bypass
operations to do something useful - see dsa_switch_supports_uc_filtering().
Although in tools/testing/selftests/net/forwarding/local_termination.sh,
we made an effort to popularize better mechanisms to manage address
filters on DSA interfaces from user space - namely macvlan for unicast,
and setsockopt(IP_ADD_MEMBERSHIP) - through mtools - for multicast, the
fact is that 'bridge fdb add ... self static local' also exists as
kernel UAPI, and might be useful to someone, even if only for a quick
hack.
It seems counter-productive to block that path by implementing shim
.ndo_fdb_add and .ndo_fdb_del operations which just return -EOPNOTSUPP
in order to prevent the ndo_dflt_fdb_add() and ndo_dflt_fdb_del() from
running, although we could do that.
Accepting that cleanup is necessary seems to be the only option.
Especially since we appear to be coming back at this from a different
angle as well. Russell King is noticing that the WARN_ON() triggers even
for VLANs:
https://lore.kernel.org/netdev/Z_li8Bj8bD4-BYKQ@shell.armlinux.org.uk/
What happens in the bug report above is that dsa_port_do_vlan_del() fails,
then the VLAN entry lingers on, and then we warn on unbind and leak it.
This is not a straight revert of the blamed commit, but we now add an
informational print to the kernel log (to still have a way to see
that bugs exist), and some extra comments gathered from past years'
experience, to justify the logic.