In the Linux kernel, the following vulnerability has been resolved:
media: hi846: fix usage of pm_runtime_get_if_in_use()
pm_runtime_get_if_in_use() does not only return nonzero values when
the device is in use, it can return a negative errno too.
And especially during resuming from system suspend, when runtime pm
is not yet up again, -EAGAIN is being returned, so the subsequent
pm_runtime_put() call results in a refcount underflow.
Fix system-resume by handling -EAGAIN of pm_runtime_get_if_in_use().
In the Linux kernel, the following vulnerability has been resolved:
mm: fix zswap writeback race condition
The zswap writeback mechanism can cause a race condition resulting in
memory corruption, where a swapped out page gets swapped in with data that
was written to a different page.
The race unfolds like this:
1. a page with data A and swap offset X is stored in zswap
2. page A is removed off the LRU by zpool driver for writeback in
zswap-shrink work, data for A is mapped by zpool driver
3. user space program faults and invalidates page entry A, offset X is
considered free
4. kswapd stores page B at offset X in zswap (zswap could also be
full, if so, page B would then be IOed to X, then skip step 5.)
5. entry A is replaced by B in tree->rbroot, this doesn't affect the
local reference held by zswap-shrink work
6. zswap-shrink work writes back A at X, and frees zswap entry A
7. swapin of slot X brings A in memory instead of B
The fix:
Once the swap page cache has been allocated (case ZSWAP_SWAPCACHE_NEW),
zswap-shrink work just checks that the local zswap_entry reference is
still the same as the one in the tree. If it's not the same it means that
it's either been invalidated or replaced, in both cases the writeback is
aborted because the local entry contains stale data.
Reproducer:
I originally found this by running `stress` overnight to validate my work
on the zswap writeback mechanism, it manifested after hours on my test
machine. The key to make it happen is having zswap writebacks, so
whatever setup pumps /sys/kernel/debug/zswap/written_back_pages should do
the trick.
In order to reproduce this faster on a vm, I setup a system with ~100M of
available memory and a 500M swap file, then running `stress --vm 1
--vm-bytes 300000000 --vm-stride 4000` makes it happen in matter of tens
of minutes. One can speed things up even more by swinging
/sys/module/zswap/parameters/max_pool_percent up and down between, say, 20
and 1; this makes it reproduce in tens of seconds. It's crucial to set
`--vm-stride` to something other than 4096 otherwise `stress` won't
realize that memory has been corrupted because all pages would have the
same data.
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ipset: add the missing IP_SET_HASH_WITH_NET0 macro for ip_set_hash_netportnet.c
The missing IP_SET_HASH_WITH_NET0 macro in ip_set_hash_netportnet can
lead to the use of wrong `CIDR_POS(c)` for calculating array offsets,
which can lead to integer underflow. As a result, it leads to slab
out-of-bound access.
This patch adds back the IP_SET_HASH_WITH_NET0 macro to
ip_set_hash_netportnet to address the issue.
In the Linux kernel, the following vulnerability has been resolved:
udf: Fix uninitialized array access for some pathnames
For filenames that begin with . and are between 2 and 5 characters long,
UDF charset conversion code would read uninitialized memory in the
output buffer. The only practical impact is that the name may be prepended a
"unification hash" when it is not actually needed but still it is good
to fix this.
In the Linux kernel, the following vulnerability has been resolved:
power: supply: bq25890: Fix external_power_changed race
bq25890_charger_external_power_changed() dereferences bq->charger,
which gets sets in bq25890_power_supply_init() like this:
bq->charger = devm_power_supply_register(bq->dev, &bq->desc, &psy_cfg);
As soon as devm_power_supply_register() has called device_add()
the external_power_changed callback can get called. So there is a window
where bq25890_charger_external_power_changed() may get called while
bq->charger has not been set yet leading to a NULL pointer dereference.
This race hits during boot sometimes on a Lenovo Yoga Book 1 yb1-x90f
when the cht_wcove_pwrsrc (extcon) power_supply is done with detecting
the connected charger-type which happens to exactly hit the small window:
BUG: kernel NULL pointer dereference, address: 0000000000000018
<snip>
RIP: 0010:__power_supply_is_supplied_by+0xb/0xb0
<snip>
Call Trace:
<TASK>
__power_supply_get_supplier_property+0x19/0x50
class_for_each_device+0xb1/0xe0
power_supply_get_property_from_supplier+0x2e/0x50
bq25890_charger_external_power_changed+0x38/0x1b0 [bq25890_charger]
__power_supply_changed_work+0x30/0x40
class_for_each_device+0xb1/0xe0
power_supply_changed_work+0x5f/0xe0
<snip>
Fixing this is easy. The external_power_changed callback gets passed
the power_supply which will eventually get stored in bq->charger,
so bq25890_charger_external_power_changed() can simply directly use
the passed in psy argument which is always valid.
In the Linux kernel, the following vulnerability has been resolved:
tracing: Fix null pointer dereference in tracing_err_log_open()
Fix an issue in function 'tracing_err_log_open'.
The function doesn't call 'seq_open' if the file is opened only with
write permissions, which results in 'file->private_data' being left as null.
If we then use 'lseek' on that opened file, 'seq_lseek' dereferences
'file->private_data' in 'mutex_lock(&m->lock)', resulting in a kernel panic.
Writing to this node requires root privileges, therefore this bug
has very little security impact.
Tracefs node: /sys/kernel/tracing/error_log
Example Kernel panic:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000038
Call trace:
mutex_lock+0x30/0x110
seq_lseek+0x34/0xb8
__arm64_sys_lseek+0x6c/0xb8
invoke_syscall+0x58/0x13c
el0_svc_common+0xc4/0x10c
do_el0_svc+0x24/0x98
el0_svc+0x24/0x88
el0t_64_sync_handler+0x84/0xe4
el0t_64_sync+0x1b4/0x1b8
Code: d503201f aa0803e0 aa1f03e1 aa0103e9 (c8e97d02)
---[ end trace 561d1b49c12cf8a5 ]---
Kernel panic - not syncing: Oops: Fatal exception
In the Linux kernel, the following vulnerability has been resolved:
usb: ucsi_acpi: Increase the command completion timeout
Commit 130a96d698d7 ("usb: typec: ucsi: acpi: Increase command
completion timeout value") increased the timeout from 5 seconds
to 60 seconds due to issues related to alternate mode discovery.
After the alternate mode discovery switch to polled mode
the timeout was reduced, but instead of being set back to
5 seconds it was reduced to 1 second.
This is causing problems when using a Lenovo ThinkPad X1 yoga gen7
connected over Type-C to a LG 27UL850-W (charging DP over Type-C).
When the monitor is already connected at boot the following error
is logged: "PPM init failed (-110)", /sys/class/typec is empty and
on unplugging the NULL pointer deref fixed earlier in this series
happens.
When the monitor is connected after boot the following error
is logged instead: "GET_CONNECTOR_STATUS failed (-110)".
Setting the timeout back to 5 seconds fixes both cases.
In the Linux kernel, the following vulnerability has been resolved:
x86/resctrl: Clear staged_config[] before and after it is used
As a temporary storage, staged_config[] in rdt_domain should be cleared
before and after it is used. The stale value in staged_config[] could
cause an MSR access error.
Here is a reproducer on a system with 16 usable CLOSIDs for a 15-way L3
Cache (MBA should be disabled if the number of CLOSIDs for MB is less than
16.) :
mount -t resctrl resctrl -o cdp /sys/fs/resctrl
mkdir /sys/fs/resctrl/p{1..7}
umount /sys/fs/resctrl/
mount -t resctrl resctrl /sys/fs/resctrl
mkdir /sys/fs/resctrl/p{1..8}
An error occurs when creating resource group named p8:
unchecked MSR access error: WRMSR to 0xca0 (tried to write 0x00000000000007ff) at rIP: 0xffffffff82249142 (cat_wrmsr+0x32/0x60)
Call Trace:
<IRQ>
__flush_smp_call_function_queue+0x11d/0x170
__sysvec_call_function+0x24/0xd0
sysvec_call_function+0x89/0xc0
</IRQ>
<TASK>
asm_sysvec_call_function+0x16/0x20
When creating a new resource control group, hardware will be configured
by the following process:
rdtgroup_mkdir()
rdtgroup_mkdir_ctrl_mon()
rdtgroup_init_alloc()
resctrl_arch_update_domains()
resctrl_arch_update_domains() iterates and updates all resctrl_conf_type
whose have_new_ctrl is true. Since staged_config[] holds the same values as
when CDP was enabled, it will continue to update the CDP_CODE and CDP_DATA
configurations. When group p8 is created, get_config_index() called in
resctrl_arch_update_domains() will return 16 and 17 as the CLOSIDs for
CDP_CODE and CDP_DATA, which will be translated to an invalid register -
0xca0 in this scenario.
Fix it by clearing staged_config[] before and after it is used.
[reinette: re-order commit tags]
In the Linux kernel, the following vulnerability has been resolved:
igb: Fix igb_down hung on surprise removal
In a setup where a Thunderbolt hub connects to Ethernet and a display
through USB Type-C, users may experience a hung task timeout when they
remove the cable between the PC and the Thunderbolt hub.
This is because the igb_down function is called multiple times when
the Thunderbolt hub is unplugged. For example, the igb_io_error_detected
triggers the first call, and the igb_remove triggers the second call.
The second call to igb_down will block at napi_synchronize.
Here's the call trace:
__schedule+0x3b0/0xddb
? __mod_timer+0x164/0x5d3
schedule+0x44/0xa8
schedule_timeout+0xb2/0x2a4
? run_local_timers+0x4e/0x4e
msleep+0x31/0x38
igb_down+0x12c/0x22a [igb 6615058754948bfde0bf01429257eb59f13030d4]
__igb_close+0x6f/0x9c [igb 6615058754948bfde0bf01429257eb59f13030d4]
igb_close+0x23/0x2b [igb 6615058754948bfde0bf01429257eb59f13030d4]
__dev_close_many+0x95/0xec
dev_close_many+0x6e/0x103
unregister_netdevice_many+0x105/0x5b1
unregister_netdevice_queue+0xc2/0x10d
unregister_netdev+0x1c/0x23
igb_remove+0xa7/0x11c [igb 6615058754948bfde0bf01429257eb59f13030d4]
pci_device_remove+0x3f/0x9c
device_release_driver_internal+0xfe/0x1b4
pci_stop_bus_device+0x5b/0x7f
pci_stop_bus_device+0x30/0x7f
pci_stop_bus_device+0x30/0x7f
pci_stop_and_remove_bus_device+0x12/0x19
pciehp_unconfigure_device+0x76/0xe9
pciehp_disable_slot+0x6e/0x131
pciehp_handle_presence_or_link_change+0x7a/0x3f7
pciehp_ist+0xbe/0x194
irq_thread_fn+0x22/0x4d
? irq_thread+0x1fd/0x1fd
irq_thread+0x17b/0x1fd
? irq_forced_thread_fn+0x5f/0x5f
kthread+0x142/0x153
? __irq_get_irqchip_state+0x46/0x46
? kthread_associate_blkcg+0x71/0x71
ret_from_fork+0x1f/0x30
In this case, igb_io_error_detected detaches the network interface
and requests a PCIE slot reset, however, the PCIE reset callback is
not being invoked and thus the Ethernet connection breaks down.
As the PCIE error in this case is a non-fatal one, requesting a
slot reset can be avoided.
This patch fixes the task hung issue and preserves Ethernet
connection by ignoring non-fatal PCIE errors.