In the Linux kernel, the following vulnerability has been resolved:
USB: chipidea: 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.
In the Linux kernel, the following vulnerability has been resolved:
scsi: target: iscsi: Fix a race condition between login_work and the login thread
In case a malicious initiator sends some random data immediately after a
login PDU; the iscsi_target_sk_data_ready() callback will schedule the
login_work and, at the same time, the negotiation may end without clearing
the LOGIN_FLAGS_INITIAL_PDU flag (because no additional PDU exchanges are
required to complete the login).
The login has been completed but the login_work function will find the
LOGIN_FLAGS_INITIAL_PDU flag set and will never stop from rescheduling
itself; at this point, if the initiator drops the connection, the
iscsit_conn structure will be freed, login_work will dereference a released
socket structure and the kernel crashes.
BUG: kernel NULL pointer dereference, address: 0000000000000230
PF: supervisor write access in kernel mode
PF: error_code(0x0002) - not-present page
Workqueue: events iscsi_target_do_login_rx [iscsi_target_mod]
RIP: 0010:_raw_read_lock_bh+0x15/0x30
Call trace:
iscsi_target_do_login_rx+0x75/0x3f0 [iscsi_target_mod]
process_one_work+0x1e8/0x3c0
Fix this bug by forcing login_work to stop after the login has been
completed and the socket callbacks have been restored.
Add a comment to clearify the return values of iscsi_target_do_login()
In the Linux kernel, the following vulnerability has been resolved:
xfs: do not propagate ENODATA disk errors into xattr code
ENODATA (aka ENOATTR) has a very specific meaning in the xfs xattr code;
namely, that the requested attribute name could not be found.
However, a medium error from disk may also return ENODATA. At best,
this medium error may escape to userspace as "attribute not found"
when in fact it's an IO (disk) error.
At worst, we may oops in xfs_attr_leaf_get() when we do:
error = xfs_attr_leaf_hasname(args, &bp);
if (error == -ENOATTR) {
xfs_trans_brelse(args->trans, bp);
return error;
}
because an ENODATA/ENOATTR error from disk leaves us with a null bp,
and the xfs_trans_brelse will then null-deref it.
As discussed on the list, we really need to modify the lower level
IO functions to trap all disk errors and ensure that we don't let
unique errors like this leak up into higher xfs functions - many
like this should be remapped to EIO.
However, this patch directly addresses a reported bug in the xattr
code, and should be safe to backport to stable kernels. A larger-scope
patch to handle more unique errors at lower levels can follow later.
(Note, prior to 07120f1abdff we did not oops, but we did return the
wrong error code to userspace.)
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:
KVM: x86: use array_index_nospec with indices that come from guest
min and dest_id are guest-controlled indices. Using array_index_nospec()
after the bounds checks clamps these values to mitigate speculative execution
side-channels.