In the Linux kernel, the following vulnerability has been resolved:
drivers: staging: rtl8723bs: Fix locking in _rtw_join_timeout_handler()
Commit 041879b12ddb ("drivers: staging: rtl8192bs: Fix deadlock in
rtw_joinbss_event_prehandle()") besides fixing the deadlock also
modified _rtw_join_timeout_handler() to use spin_[un]lock_irq()
instead of spin_[un]lock_bh().
_rtw_join_timeout_handler() calls rtw_do_join() which takes
pmlmepriv->scanned_queue.lock using spin_[un]lock_bh(). This
spin_unlock_bh() call re-enables softirqs which triggers an oops in
kernel/softirq.c: __local_bh_enable_ip() when it calls
lockdep_assert_irqs_enabled():
[ 244.506087] WARNING: CPU: 2 PID: 0 at kernel/softirq.c:376 __local_bh_enable_ip+0xa6/0x100
...
[ 244.509022] Call Trace:
[ 244.509048] <IRQ>
[ 244.509100] _rtw_join_timeout_handler+0x134/0x170 [r8723bs]
[ 244.509468] ? __pfx__rtw_join_timeout_handler+0x10/0x10 [r8723bs]
[ 244.509772] ? __pfx__rtw_join_timeout_handler+0x10/0x10 [r8723bs]
[ 244.510076] call_timer_fn+0x95/0x2a0
[ 244.510200] __run_timers.part.0+0x1da/0x2d0
This oops is causd by the switch to spin_[un]lock_irq() which disables
the IRQs for the entire duration of _rtw_join_timeout_handler().
Disabling the IRQs is not necessary since all code taking this lock
runs from either user contexts or from softirqs, switch back to
spin_[un]lock_bh() to fix this.
In the Linux kernel, the following vulnerability has been resolved:
ext4: add bounds checking in get_max_inline_xattr_value_size()
Normally the extended attributes in the inode body would have been
checked when the inode is first opened, but if someone is writing to
the block device while the file system is mounted, it's possible for
the inode table to get corrupted. Add bounds checking to avoid
reading beyond the end of allocated memory if this happens.
In the Linux kernel, the following vulnerability has been resolved:
usb: cdns3: Put the cdns set active part outside the spin lock
The device may be scheduled during the resume process,
so this cannot appear in atomic operations. Since
pm_runtime_set_active will resume suppliers, put set
active outside the spin lock, which is only used to
protect the struct cdns data structure, otherwise the
kernel will report the following warning:
BUG: sleeping function called from invalid context at drivers/base/power/runtime.c:1163
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 651, name: sh
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
CPU: 0 PID: 651 Comm: sh Tainted: G WC 6.1.20 #1
Hardware name: Freescale i.MX8QM MEK (DT)
Call trace:
dump_backtrace.part.0+0xe0/0xf0
show_stack+0x18/0x30
dump_stack_lvl+0x64/0x80
dump_stack+0x1c/0x38
__might_resched+0x1fc/0x240
__might_sleep+0x68/0xc0
__pm_runtime_resume+0x9c/0xe0
rpm_get_suppliers+0x68/0x1b0
__pm_runtime_set_status+0x298/0x560
cdns_resume+0xb0/0x1c0
cdns3_controller_resume.isra.0+0x1e0/0x250
cdns3_plat_resume+0x28/0x40
In the Linux kernel, the following vulnerability has been resolved:
drm/client: Fix memory leak in drm_client_modeset_probe
When a new mode is set to modeset->mode, the previous mode should be freed.
This fixes the following kmemleak report:
drm_mode_duplicate+0x45/0x220 [drm]
drm_client_modeset_probe+0x944/0xf50 [drm]
__drm_fb_helper_initial_config_and_unlock+0xb4/0x2c0 [drm_kms_helper]
drm_fbdev_client_hotplug+0x2bc/0x4d0 [drm_kms_helper]
drm_client_register+0x169/0x240 [drm]
ast_pci_probe+0x142/0x190 [ast]
local_pci_probe+0xdc/0x180
work_for_cpu_fn+0x4e/0xa0
process_one_work+0x8b7/0x1540
worker_thread+0x70a/0xed0
kthread+0x29f/0x340
ret_from_fork+0x1f/0x30
In the Linux kernel, the following vulnerability has been resolved:
net: ena: fix shift-out-of-bounds in exponential backoff
The ENA adapters on our instances occasionally reset. Once recently
logged a UBSAN failure to console in the process:
UBSAN: shift-out-of-bounds in build/linux/drivers/net/ethernet/amazon/ena/ena_com.c:540:13
shift exponent 32 is too large for 32-bit type 'unsigned int'
CPU: 28 PID: 70012 Comm: kworker/u72:2 Kdump: loaded not tainted 5.15.117
Hardware name: Amazon EC2 c5d.9xlarge/, BIOS 1.0 10/16/2017
Workqueue: ena ena_fw_reset_device [ena]
Call Trace:
<TASK>
dump_stack_lvl+0x4a/0x63
dump_stack+0x10/0x16
ubsan_epilogue+0x9/0x36
__ubsan_handle_shift_out_of_bounds.cold+0x61/0x10e
? __const_udelay+0x43/0x50
ena_delay_exponential_backoff_us.cold+0x16/0x1e [ena]
wait_for_reset_state+0x54/0xa0 [ena]
ena_com_dev_reset+0xc8/0x110 [ena]
ena_down+0x3fe/0x480 [ena]
ena_destroy_device+0xeb/0xf0 [ena]
ena_fw_reset_device+0x30/0x50 [ena]
process_one_work+0x22b/0x3d0
worker_thread+0x4d/0x3f0
? process_one_work+0x3d0/0x3d0
kthread+0x12a/0x150
? set_kthread_struct+0x50/0x50
ret_from_fork+0x22/0x30
</TASK>
Apparently, the reset delays are getting so large they can trigger a
UBSAN panic.
Looking at the code, the current timeout is capped at 5000us. Using a
base value of 100us, the current code will overflow after (1<<29). Even
at values before 32, this function wraps around, perhaps
unintentionally.
Cap the value of the exponent used for this backoff at (1<<16) which is
larger than currently necessary, but large enough to support bigger
values in the future.
In the Linux kernel, the following vulnerability has been resolved:
Drivers: vmbus: Check for channel allocation before looking up relids
relid2channel() assumes vmbus channel array to be allocated when called.
However, in cases such as kdump/kexec, not all relids will be reset by the host.
When the second kernel boots and if the guest receives a vmbus interrupt during
vmbus driver initialization before vmbus_connect() is called, before it finishes,
or if it fails, the vmbus interrupt service routine is called which in turn calls
relid2channel() and can cause a null pointer dereference.
Print a warning and error out in relid2channel() for a channel id that's invalid
in the second kernel.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: hda: fix a possible null-pointer dereference due to data race in snd_hdac_regmap_sync()
The variable codec->regmap is often protected by the lock
codec->regmap_lock when is accessed. However, it is accessed without
holding the lock when is accessed in snd_hdac_regmap_sync():
if (codec->regmap)
In my opinion, this may be a harmful race, because if codec->regmap is
set to NULL right after the condition is checked, a null-pointer
dereference can occur in the called function regcache_sync():
map->lock(map->lock_arg); --> Line 360 in drivers/base/regmap/regcache.c
To fix this possible null-pointer dereference caused by data race, the
mutex_lock coverage is extended to protect the if statement as well as the
function call to regcache_sync().
[ Note: the lack of the regmap_lock itself is harmless for the current
codec driver implementations, as snd_hdac_regmap_sync() is only for
PM runtime resume that is prohibited during the codec probe.
But the change makes the whole code more consistent, so it's merged
as is -- tiwai ]
In the Linux kernel, the following vulnerability has been resolved:
ubifs: Free memory for tmpfile name
When opening a ubifs tmpfile on an encrypted directory, function
fscrypt_setup_filename allocates memory for the name that is to be
stored in the directory entry, but after the name has been copied to the
directory entry inode, the memory is not freed.
When running kmemleak on it we see that it is registered as a leak. The
report below is triggered by a simple program 'tmpfile' just opening a
tmpfile:
unreferenced object 0xffff88810178f380 (size 32):
comm "tmpfile", pid 509, jiffies 4294934744 (age 1524.742s)
backtrace:
__kmem_cache_alloc_node
__kmalloc
fscrypt_setup_filename
ubifs_tmpfile
vfs_tmpfile
path_openat
Free this memory after it has been copied to the inode.