In the Linux kernel, the following vulnerability has been resolved:
trace/fgraph: Fix the warning caused by missing unregister notifier
This warning was triggered during testing on v6.16:
notifier callback ftrace_suspend_notifier_call already registered
WARNING: CPU: 2 PID: 86 at kernel/notifier.c:23 notifier_chain_register+0x44/0xb0
...
Call Trace:
<TASK>
blocking_notifier_chain_register+0x34/0x60
register_ftrace_graph+0x330/0x410
ftrace_profile_write+0x1e9/0x340
vfs_write+0xf8/0x420
? filp_flush+0x8a/0xa0
? filp_close+0x1f/0x30
? do_dup2+0xaf/0x160
ksys_write+0x65/0xe0
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x77/0x7f
When writing to the function_profile_enabled interface, the notifier was
not unregistered after start_graph_tracing failed, causing a warning the
next time function_profile_enabled was written.
Fixed by adding unregister_pm_notifier in the exception path.
In the Linux kernel, the following vulnerability has been resolved:
net: rose: convert 'use' field to refcount_t
The 'use' field in struct rose_neigh is used as a reference counter but
lacks atomicity. This can lead to race conditions where a rose_neigh
structure is freed while still being referenced by other code paths.
For example, when rose_neigh->use becomes zero during an ioctl operation
via rose_rt_ioctl(), the structure may be removed while its timer is
still active, potentially causing use-after-free issues.
This patch changes the type of 'use' from unsigned short to refcount_t and
updates all code paths to use rose_neigh_hold() and rose_neigh_put() which
operate reference counts atomically.
In the Linux kernel, the following vulnerability has been resolved:
net: rose: include node references in rose_neigh refcount
Current implementation maintains two separate reference counting
mechanisms: the 'count' field in struct rose_neigh tracks references from
rose_node structures, while the 'use' field (now refcount_t) tracks
references from rose_sock.
This patch merges these two reference counting systems using 'use' field
for proper reference management. Specifically, this patch adds incrementing
and decrementing of rose_neigh->use when rose_neigh->count is incremented
or decremented.
This patch also modifies rose_rt_free(), rose_rt_device_down() and
rose_clear_route() to properly release references to rose_neigh objects
before freeing a rose_node through rose_remove_node().
These changes ensure rose_neigh structures are properly freed only when
all references, including those from rose_node structures, are released.
As a result, this resolves a slab-use-after-free issue reported by Syzbot.
In the Linux kernel, the following vulnerability has been resolved:
HID: asus: fix UAF via HID_CLAIMED_INPUT validation
After hid_hw_start() is called hidinput_connect() will eventually be
called to set up the device with the input layer since the
HID_CONNECT_DEFAULT connect mask is used. During hidinput_connect()
all input and output reports are processed and corresponding hid_inputs
are allocated and configured via hidinput_configure_usages(). This
process involves slot tagging report fields and configuring usages
by setting relevant bits in the capability bitmaps. However it is possible
that the capability bitmaps are not set at all leading to the subsequent
hidinput_has_been_populated() check to fail leading to the freeing of the
hid_input and the underlying input device.
This becomes problematic because a malicious HID device like a
ASUS ROG N-Key keyboard can trigger the above scenario via a
specially crafted descriptor which then leads to a user-after-free
when the name of the freed input device is written to later on after
hid_hw_start(). Below, report 93 intentionally utilises the
HID_UP_UNDEFINED Usage Page which is skipped during usage
configuration, leading to the frees.
0x05, 0x0D, // Usage Page (Digitizer)
0x09, 0x05, // Usage (Touch Pad)
0xA1, 0x01, // Collection (Application)
0x85, 0x0D, // Report ID (13)
0x06, 0x00, 0xFF, // Usage Page (Vendor Defined 0xFF00)
0x09, 0xC5, // Usage (0xC5)
0x15, 0x00, // Logical Minimum (0)
0x26, 0xFF, 0x00, // Logical Maximum (255)
0x75, 0x08, // Report Size (8)
0x95, 0x04, // Report Count (4)
0xB1, 0x02, // Feature (Data,Var,Abs)
0x85, 0x5D, // Report ID (93)
0x06, 0x00, 0x00, // Usage Page (Undefined)
0x09, 0x01, // Usage (0x01)
0x15, 0x00, // Logical Minimum (0)
0x26, 0xFF, 0x00, // Logical Maximum (255)
0x75, 0x08, // Report Size (8)
0x95, 0x1B, // Report Count (27)
0x81, 0x02, // Input (Data,Var,Abs)
0xC0, // End Collection
Below is the KASAN splat after triggering the UAF:
[ 21.672709] ==================================================================
[ 21.673700] BUG: KASAN: slab-use-after-free in asus_probe+0xeeb/0xf80
[ 21.673700] Write of size 8 at addr ffff88810a0ac000 by task kworker/1:2/54
[ 21.673700]
[ 21.673700] CPU: 1 UID: 0 PID: 54 Comm: kworker/1:2 Not tainted 6.16.0-rc4-g9773391cf4dd-dirty #36 PREEMPT(voluntary)
[ 21.673700] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
[ 21.673700] Call Trace:
[ 21.673700] <TASK>
[ 21.673700] dump_stack_lvl+0x5f/0x80
[ 21.673700] print_report+0xd1/0x660
[ 21.673700] kasan_report+0xe5/0x120
[ 21.673700] __asan_report_store8_noabort+0x1b/0x30
[ 21.673700] asus_probe+0xeeb/0xf80
[ 21.673700] hid_device_probe+0x2ee/0x700
[ 21.673700] really_probe+0x1c6/0x6b0
[ 21.673700] __driver_probe_device+0x24f/0x310
[ 21.673700] driver_probe_device+0x4e/0x220
[...]
[ 21.673700]
[ 21.673700] Allocated by task 54:
[ 21.673700] kasan_save_stack+0x3d/0x60
[ 21.673700] kasan_save_track+0x18/0x40
[ 21.673700] kasan_save_alloc_info+0x3b/0x50
[ 21.673700] __kasan_kmalloc+0x9c/0xa0
[ 21.673700] __kmalloc_cache_noprof+0x139/0x340
[ 21.673700] input_allocate_device+0x44/0x370
[ 21.673700] hidinput_connect+0xcb6/0x2630
[ 21.673700] hid_connect+0xf74/0x1d60
[ 21.673700] hid_hw_start+0x8c/0x110
[ 21.673700] asus_probe+0x5a3/0xf80
[ 21.673700] hid_device_probe+0x2ee/0x700
[ 21.673700] really_probe+0x1c6/0x6b0
[ 21.673700] __driver_probe_device+0x24f/0x310
[ 21.673700] driver_probe_device+0x4e/0x220
[...]
[ 21.673700]
[ 21.673700] Freed by task 54:
[ 21.673700] kasan_save_stack+0x3d/0x60
[ 21.673700] kasan_save_track+0x18/0x40
[ 21.673700] kasan_save_free_info+0x3f/0x60
[ 21.673700] __kasan_slab_free+0x3c/0x50
[ 21.673700] kfre
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
efivarfs: Fix slab-out-of-bounds in efivarfs_d_compare
Observed on kernel 6.6 (present on master as well):
BUG: KASAN: slab-out-of-bounds in memcmp+0x98/0xd0
Call trace:
kasan_check_range+0xe8/0x190
__asan_loadN+0x1c/0x28
memcmp+0x98/0xd0
efivarfs_d_compare+0x68/0xd8
__d_lookup_rcu_op_compare+0x178/0x218
__d_lookup_rcu+0x1f8/0x228
d_alloc_parallel+0x150/0x648
lookup_open.isra.0+0x5f0/0x8d0
open_last_lookups+0x264/0x828
path_openat+0x130/0x3f8
do_filp_open+0x114/0x248
do_sys_openat2+0x340/0x3c0
__arm64_sys_openat+0x120/0x1a0
If dentry->d_name.len < EFI_VARIABLE_GUID_LEN , 'guid' can become
negative, leadings to oob. The issue can be triggered by parallel
lookups using invalid filename:
T1 T2
lookup_open
->lookup
simple_lookup
d_add
// invalid dentry is added to hash list
lookup_open
d_alloc_parallel
__d_lookup_rcu
__d_lookup_rcu_op_compare
hlist_bl_for_each_entry_rcu
// invalid dentry can be retrieved
->d_compare
efivarfs_d_compare
// oob
Fix it by checking 'guid' before cmp.
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:
Bluetooth: L2CAP: fix "bad unlock balance" in l2cap_disconnect_rsp
conn->chan_lock isn't acquired before l2cap_get_chan_by_scid,
if l2cap_get_chan_by_scid returns NULL, then 'bad unlock balance'
is triggered.