In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix use-after-free in cifs_oplock_break
A race condition can occur in cifs_oplock_break() leading to a
use-after-free of the cinode structure when unmounting:
cifs_oplock_break()
_cifsFileInfo_put(cfile)
cifsFileInfo_put_final()
cifs_sb_deactive()
[last ref, start releasing sb]
kill_sb()
kill_anon_super()
generic_shutdown_super()
evict_inodes()
dispose_list()
evict()
destroy_inode()
call_rcu(&inode->i_rcu, i_callback)
spin_lock(&cinode->open_file_lock) <- OK
[later] i_callback()
cifs_free_inode()
kmem_cache_free(cinode)
spin_unlock(&cinode->open_file_lock) <- UAF
cifs_done_oplock_break(cinode) <- UAF
The issue occurs when umount has already released its reference to the
superblock. When _cifsFileInfo_put() calls cifs_sb_deactive(), this
releases the last reference, triggering the immediate cleanup of all
inodes under RCU. However, cifs_oplock_break() continues to access the
cinode after this point, resulting in use-after-free.
Fix this by holding an extra reference to the superblock during the
entire oplock break operation. This ensures that the superblock and
its inodes remain valid until the oplock break completes.
In the Linux kernel, the following vulnerability has been resolved:
comedi: aio_iiro_16: Fix bit shift out of bounds
When checking for a supported IRQ number, the following test is used:
if ((1 << it->options[1]) & 0xdcfc) {
However, `it->options[i]` is an unchecked `int` value from userspace, so
the shift amount could be negative or out of bounds. Fix the test by
requiring `it->options[1]` to be within bounds before proceeding with
the original test. Valid `it->options[1]` values that select the IRQ
will be in the range [1,15]. The value 0 explicitly disables the use of
interrupts.
In the Linux kernel, the following vulnerability has been resolved:
comedi: pcl812: Fix bit shift out of bounds
When checking for a supported IRQ number, the following test is used:
if ((1 << it->options[1]) & board->irq_bits) {
However, `it->options[i]` is an unchecked `int` value from userspace, so
the shift amount could be negative or out of bounds. Fix the test by
requiring `it->options[1]` to be within bounds before proceeding with
the original test. Valid `it->options[1]` values that select the IRQ
will be in the range [1,15]. The value 0 explicitly disables the use of
interrupts.
In the Linux kernel, the following vulnerability has been resolved:
iio: common: st_sensors: Fix use of uninitialize device structs
Throughout the various probe functions &indio_dev->dev is used before it
is initialized. This caused a kernel panic in st_sensors_power_enable()
when the call to devm_regulator_bulk_get_enable() fails and then calls
dev_err_probe() with the uninitialized device.
This seems to only cause a panic with dev_err_probe(), dev_err(),
dev_warn() and dev_info() don't seem to cause a panic, but are fixed
as well.
The issue is reported and traced here: [1]
In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Fix recv-recv race of completed call
If a call receives an event (such as incoming data), the call gets placed
on the socket's queue and a thread in recvmsg can be awakened to go and
process it. Once the thread has picked up the call off of the queue,
further events will cause it to be requeued, and once the socket lock is
dropped (recvmsg uses call->user_mutex to allow the socket to be used in
parallel), a second thread can come in and its recvmsg can pop the call off
the socket queue again.
In such a case, the first thread will be receiving stuff from the call and
the second thread will be blocked on call->user_mutex. The first thread
can, at this point, process both the event that it picked call for and the
event that the second thread picked the call for and may see the call
terminate - in which case the call will be "released", decoupling the call
from the user call ID assigned to it (RXRPC_USER_CALL_ID in the control
message).
The first thread will return okay, but then the second thread will wake up
holding the user_mutex and, if it sees that the call has been released by
the first thread, it will BUG thusly:
kernel BUG at net/rxrpc/recvmsg.c:474!
Fix this by just dequeuing the call and ignoring it if it is seen to be
already released. We can't tell userspace about it anyway as the user call
ID has become stale.
In the Linux kernel, the following vulnerability has been resolved:
wifi: zd1211rw: Fix potential NULL pointer dereference in zd_mac_tx_to_dev()
There is a potential NULL pointer dereference in zd_mac_tx_to_dev(). For
example, the following is possible:
T0 T1
zd_mac_tx_to_dev()
/* len == skb_queue_len(q) */
while (len > ZD_MAC_MAX_ACK_WAITERS) {
filter_ack()
spin_lock_irqsave(&q->lock, flags);
/* position == skb_queue_len(q) */
for (i=1; i<position; i++)
skb = __skb_dequeue(q)
if (mac->type == NL80211_IFTYPE_AP)
skb = __skb_dequeue(q);
spin_unlock_irqrestore(&q->lock, flags);
skb_dequeue() -> NULL
Since there is a small gap between checking skb queue length and skb being
unconditionally dequeued in zd_mac_tx_to_dev(), skb_dequeue() can return NULL.
Then the pointer is passed to zd_mac_tx_status() where it is dereferenced.
In order to avoid potential NULL pointer dereference due to situations like
above, check if skb is not NULL before passing it to zd_mac_tx_status().
Found by Linux Verification Center (linuxtesting.org) with SVACE.
In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Fix oops due to non-existence of prealloc backlog struct
If an AF_RXRPC service socket is opened and bound, but calls are
preallocated, then rxrpc_alloc_incoming_call() will oops because the
rxrpc_backlog struct doesn't get allocated until the first preallocation is
made.
Fix this by returning NULL from rxrpc_alloc_incoming_call() if there is no
backlog struct. This will cause the incoming call to be aborted.
In the Linux kernel, the following vulnerability has been resolved:
pinctrl: qcom: msm: mark certain pins as invalid for interrupts
On some platforms, the UFS-reset pin has no interrupt logic in TLMM but
is nevertheless registered as a GPIO in the kernel. This enables the
user-space to trigger a BUG() in the pinctrl-msm driver by running, for
example: `gpiomon -c 0 113` on RB2.
The exact culprit is requesting pins whose intr_detection_width setting
is not 1 or 2 for interrupts. This hits a BUG() in
msm_gpio_irq_set_type(). Potentially crashing the kernel due to an
invalid request from user-space is not optimal, so let's go through the
pins and mark those that would fail the check as invalid for the irq chip
as we should not even register them as available irqs.
This function can be extended if we determine that there are more
corner-cases like this.
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: eir: Fix using strlen with hdev->{dev_name,short_name}
Both dev_name and short_name are not guaranteed to be NULL terminated so
this instead use strnlen and then attempt to determine if the resulting
string needs to be truncated or not.
In the Linux kernel, the following vulnerability has been resolved:
do_change_type(): refuse to operate on unmounted/not ours mounts
Ensure that propagation settings can only be changed for mounts located
in the caller's mount namespace. This change aligns permission checking
with the rest of mount(2).