In the Linux kernel, the following vulnerability has been resolved:
ftrace: Fix potential warning in trace_printk_seq during ftrace_dump
When calling ftrace_dump_one() concurrently with reading trace_pipe,
a WARN_ON_ONCE() in trace_printk_seq() can be triggered due to a race
condition.
The issue occurs because:
CPU0 (ftrace_dump) CPU1 (reader)
echo z > /proc/sysrq-trigger
!trace_empty(&iter)
trace_iterator_reset(&iter) <- len = size = 0
cat /sys/kernel/tracing/trace_pipe
trace_find_next_entry_inc(&iter)
__find_next_entry
ring_buffer_empty_cpu <- all empty
return NULL
trace_printk_seq(&iter.seq)
WARN_ON_ONCE(s->seq.len >= s->seq.size)
In the context between trace_empty() and trace_find_next_entry_inc()
during ftrace_dump, the ring buffer data was consumed by other readers.
This caused trace_find_next_entry_inc to return NULL, failing to populate
`iter.seq`. At this point, due to the prior trace_iterator_reset, both
`iter.seq.len` and `iter.seq.size` were set to 0. Since they are equal,
the WARN_ON_ONCE condition is triggered.
Move the trace_printk_seq() into the if block that checks to make sure the
return value of trace_find_next_entry_inc() is non-NULL in
ftrace_dump_one(), ensuring the 'iter.seq' is properly populated before
subsequent operations.
In the Linux kernel, the following vulnerability has been resolved:
HID: hid-ntrig: fix unable to handle page fault in ntrig_report_version()
in ntrig_report_version(), hdev parameter passed from hid_probe().
sending descriptor to /dev/uhid can make hdev->dev.parent->parent to null
if hdev->dev.parent->parent is null, usb_dev has
invalid address(0xffffffffffffff58) that hid_to_usb_dev(hdev) returned
when usb_rcvctrlpipe() use usb_dev,it trigger
page fault error for address(0xffffffffffffff58)
add null check logic to ntrig_report_version()
before calling hid_to_usb_dev()
In the Linux kernel, the following vulnerability has been resolved:
blk-mq: fix NULL dereference on q->elevator in blk_mq_elv_switch_none
After grabbing q->sysfs_lock, q->elevator may become NULL because of
elevator switch.
Fix the NULL dereference on q->elevator by checking it with lock.
In the Linux kernel, the following vulnerability has been resolved:
scsi: lpfc: Fix use-after-free KFENCE violation during sysfs firmware write
During the sysfs firmware write process, a use-after-free read warning is
logged from the lpfc_wr_object() routine:
BUG: KFENCE: use-after-free read in lpfc_wr_object+0x235/0x310 [lpfc]
Use-after-free read at 0x0000000000cf164d (in kfence-#111):
lpfc_wr_object+0x235/0x310 [lpfc]
lpfc_write_firmware.cold+0x206/0x30d [lpfc]
lpfc_sli4_request_firmware_update+0xa6/0x100 [lpfc]
lpfc_request_firmware_upgrade_store+0x66/0xb0 [lpfc]
kernfs_fop_write_iter+0x121/0x1b0
new_sync_write+0x11c/0x1b0
vfs_write+0x1ef/0x280
ksys_write+0x5f/0xe0
do_syscall_64+0x59/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
The driver accessed wr_object pointer data, which was initialized into
mailbox payload memory, after the mailbox object was released back to the
mailbox pool.
Fix by moving the mailbox free calls to the end of the routine ensuring
that we don't reference internal mailbox memory after release.
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:
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:
misc: vmw_balloon: fix memory leak with using debugfs_lookup()
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic at
once.