| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| A TOCTOU (Time-of-Check Time-of-Use) vulnerability in GNU tar's incremental dumpdir 'X' rename handling allows a local attacker with write access to a directory being backed up to influence the restore process if the attacker has access to the system where the restore is being performed. During restoration, files or directories may be created, renamed or overwritten outside the intended extraction directory. This could lead to unauthorized file modification or, in some cases, privilege escalation. Exploitation does not require the attacker to modify or craft the archive, and standard backup and restore workflows—including extracting into a newly created directory without using the -P option do not mitigate the issue. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: SVM: Disable AVIC IPI virtualization on Hygon Family 18h (erratum #1235)
Hygon Family 18h CPUs are derived from AMD Family 17h (Zen1) silicon and
share the same erratum #1235: hardware may read a stale IsRunning=1 bit
during ICR write emulation and silently fail to generate an
AVIC_IPI_FAILURE_TARGET_NOT_RUNNING VM-Exit on the sending vCPU.
The absence of the VM-Exit causes KVM to miss the required wakeup of
blocking target vCPUs, leading to hung vCPUs and unbounded delays in
guest execution.
Extend the existing AMD Family 17h erratum #1235 workaround to also cover
Hygon Family 18h. With IPI virtualization disabled, KVM never sets
IsRunning=1 in the Physical ID table, so every non-self IPI generates a
VM-Exit and is correctly emulated. |
| In the Linux kernel, the following vulnerability has been resolved:
netfs, afs: Fix write skipping in dir/link writepages
Fix netfs_write_single() and afs_single_writepages() to better handle a
write that would be skipped due to lock contention and WB_SYNC_NONE by
returning 1 from netfs_write_single() if it skipped and making
afs_single_writepages() skip also. If a skip occurs, the inode must be
re-marked as the VFS may have cleared the mark.
This is really only theoretical for directories in netfs_write_single() as
the only path to that is through afs_single_writepages() that takes the
->validate_lock around it, thereby serialising it. |
| In the Linux kernel, the following vulnerability has been resolved:
s390/ap: use generic driver_override infrastructure
When the AP masks are updated via apmask_store() or aqmask_store(),
ap_bus_revise_bindings() is called after ap_attr_mutex has been
released.
This calls __ap_revise_reserved(), which accesses the driver_override
field without holding any lock, racing against a concurrent
driver_override_store() that may free the old string, resulting in a
potential UAF.
Fix this by using the driver-core driver_override infrastructure, which
protects all accesses with an internal spinlock.
Note that unlike most other buses, the AP bus does not check
driver_override in its match() callback; the override is checked in
ap_device_probe() and __ap_revise_reserved() instead.
Also note that we do not enable the driver_override feature of struct
bus_type, as AP - in contrast to most other buses - passes "" to
sysfs_emit() when the driver_override pointer is NULL. Thus, printing
"\n" instead of "(null)\n".
Additionally, AP has a custom counter that is modified in the
corresponding custom driver_override_store(). |
| In the Linux kernel, the following vulnerability has been resolved:
rbd: eliminate a race in lock_dwork draining on unmap
Given how rbd_lock_add_request() and rbd_img_exclusive_lock() are
written, lock_dwork may be (re)queued more than it's actually needed:
for example in case a new I/O request comes in while we are in the
middle of rbd_acquire_lock() on behalf of another I/O request. This is
expected and with rbd_release_lock() preemptively canceling lock_dwork
is benign under normal operation.
A more problematic example is maybe_kick_acquire():
if (have_requests || delayed_work_pending(&rbd_dev->lock_dwork)) {
dout("%s rbd_dev %p kicking lock_dwork\n", __func__, rbd_dev);
mod_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork, 0);
}
It's not unrealistic for lock_dwork to get canceled right after
delayed_work_pending() returns true and for mod_delayed_work() to
requeue it right there anyway. This is a classic TOCTOU race.
When it comes to unmapping the image, there is an implicit assumption
of no self-initiated exclusive lock activity past the point of return
from rbd_dev_image_unlock() which unlocks the lock if it happens to be
held. This unlock is assumed to be final and lock_dwork (as well as
all other exclusive lock tasks, really) isn't expected to get queued
again. However, lock_dwork is canceled only in cancel_tasks_sync()
(i.e. later in the unmap sequence) and on top of that the cancellation
can get in effect nullified by maybe_kick_acquire(). This may result
in rbd_acquire_lock() executing after rbd_dev_device_release() and
rbd_dev_image_release() run and free and/or reset a bunch of things.
One of the possible failure modes then is a violated
rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
in rbd_dev_header_info() which is called via rbd_dev_refresh() from
rbd_post_acquire_action().
Redo exclusive lock task draining to provide saner semantics and try
to meet the assumptions around rbd_dev_image_unlock(). |
| In the Linux kernel, the following vulnerability has been resolved:
batman-adv: bla: avoid double decrement of bla.num_requests
The bla.num_requests is increased when no request_sent was in progress. And
it is decremented in various places (announcement was received, backbone is
purged, periodic work). But the check if the request_sent is actually set
to a specific state and the atomic_dec/_inc are not safe because they are
not atomic (TOCTOU) and multiple such code portions can run concurrently.
At the same time, it is necessary to modify request_sent (state) and
bla.num_requests atomically. Otherwise batadv_bla_send_request() might set
request_sent to 1 and is interrupted. batadv_handle_announce() can then
set request_sent back to 0 and decrement num_requests before
batadv_bla_send_request() incremented it.
The two operations must therefore be locked. And since state (request_sent)
and wait_periods are only accessed inside this lock, they can be converted
to simpler datatypes. And to avoid that the bla.num_requests is touched by
a parallel running context with a valid backbone_gw reference after
batadv_bla_purge_backbone_gw() ran, a third state "stopped" is required to
correctly signal that a backbone_gw is in the state of being cleaned up. |
| In the Linux kernel, the following vulnerability has been resolved:
batman-adv: tt: fix TOCTOU race for reported vlans
The local TT based TVLV is generated by first checking the number of VLANs
which have at least one TT entry. A new buffer with the correct size for
the VLANs is then allocated. Only then, the list of VLANs s used to fill
the VLAN entries in the buffer. During this time, the meshif_vlan_list_lock
is held. But the actual number of TT entries of each VLAN can still
increase during this time - just not the number of VLANs in the list.
But the prefilter used in the buffer size calculation might still cause an
increase of the number of VLANs which need to be stored. Simply because a
VLAN might now suddenly have at least one entry when it had none in the
pre-alloc check - and then needs to occupy space which was not allocated.
It is better to overestimate the buffer size at the beginning and then fill
the buffer only with the VLANs which are not empty. |
| Time-of-check time-of-use race condition in the BIOS firmware for some Intel(R) Processors may allow a privileged user to potentially enable escalation of privilege via local access. |
| A TOCTOU (Time-of-Check-Time-of-Use) race condition vulnerability was found in the fixfiles script in policycoreutils. When running fixfiles relabel or fixfiles restore, the script used find and chcon commands to locate and relabel unlabeled files under /tmp and other directories. A local attacker could exploit a race window between the file discovery and the label change operation by swapping directory components with symlinks, causing chcon to follow the symlink and modify SELinux labels on arbitrary system files. This could undermine SELinux mandatory access control protections on critical files such as /etc/shadow. |
| A race condition in AbstractOAuthDataProvider allows concurrent requests using the same Refresh Token to bypass single-use semantics and generate multiple valid Access Tokens, when 'recycleRefreshTokens' is set to false. A leaked refresh token can be replayed concurrently by multiple attackers or threads. Users are recommended to upgrade to versions 4.2.2 or 4.1.7 or 3.6.12, which fixes this issue. |
| In the Linux kernel, the following vulnerability has been resolved:
erofs: fix managed cache race for unaligned extents
After unaligned compressed extents were introduced, the following race
could occur:
[Thread 1] [Thread 2]
(z_erofs_fill_bio_vec)
<handle a Z_EROFS_PREALLOCATED_FOLIO folio>
...
filemap_add_folio (1)
(z_erofs_bind_cache)
<the same folio is found..>
..
..
folio_attach_private (2)
filemap_add_folio (3) again
Since (1) is executed but (2) hasn't been executed yet, it's possible
that another thread finds the same managed folio in z_erofs_bind_cache()
for a different pcluster and calls filemap_add_folio() again since
folio->private is still Z_EROFS_PREALLOCATED_FOLIO.
Fix this by explicitly clearing folio->private before making the folio
visible in the managed cache so that another pcluster can simply wait
on the locked managed folio as what we did for other shared cases [1].
This only impacts unaligned data compression (`-E48bit` with zstd,
for example).
[1] Commit 9e2f9d34dd12 ("erofs: handle overlapped pclusters out of
crafted images properly") was originally introduced to handle crafted
overlapped extents, but it addresses unaligned extents as well. |
| In the Linux kernel, the following vulnerability has been resolved:
net_sched: drr: Fix double list add in class with netem as child qdisc
As described in Gerrard's report [1], there are use cases where a netem
child qdisc will make the parent qdisc's enqueue callback reentrant.
In the case of drr, there won't be a UAF, but the code will add the same
classifier to the list twice, which will cause memory corruption.
In addition to checking for qlen being zero, this patch checks whether the
class was already added to the active_list (cl_is_active) before adding
to the list to cover for the reentrant case.
[1] https://lore.kernel.org/netdev/CAHcdcOm+03OD2j6R0=YHKqmy=VgJ8xEOKuP6c7mSgnp-TEJJbw@mail.gmail.com/ |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: SEV: Use READ_ONCE() when reading entries/indices from PSC buffer
Use READ_ONCE() when reading entries/indices from the guest-accessible
Page State Change buffer to defend against TOCTOU bugs.
Don't bother with READ_ONCE()/WRITE_ONCE() for cases where KVM is writing
(and not consuming the result!), as the guest isn't supposed to touch the
buffer while it's being processed. I.e. using READ_ONCE() is all about
protecting against misbehaving guests. |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: fix race between sctp_wait_for_connect and peeloff
sctp_wait_for_connect() drops and re-acquires the socket lock while
waiting for the association to reach ESTABLISHED state. During this
window, another thread can peeloff the association to a new socket via
getsockopt(SCTP_SOCKOPT_PEELOFF), changing asoc->base.sk. After
re-acquiring the old socket lock, sctp_wait_for_connect() returns
success without noticing the migration — the caller then accesses
the association under the wrong lock in sctp_datamsg_from_user().
Add the same sk != asoc->base.sk check that sctp_wait_for_sndbuf()
already has, returning an error if the association was migrated while
we slept. |
| In the Linux kernel, the following vulnerability has been resolved:
net: shaper: rework the VALID marking (again)
Recent commit changed the semantics from NOT_VALID to VALID.
I didn't realize that the flags are not stored atomically
with the entry in XArray. There's still a race of reader
observing a VALID mark for a slot, getting interrupted,
writer replacing the entry with a different one, reader
continuing, fetching the entry which is now a different
pointer than the pointer for which VALID was meant.
The biggest consequence of this is that we may see a UAF
since net_shaper_rollback() assumed that entries without
VALID can be freed without observing RCU.
Looks like the XArray marks are buying us nothing at this
point. Let's convert the code to an explicit valid field.
The smp_load_acquire() / smp_store_release() barriers are
marginally cleaner. |
| In the Linux kernel, the following vulnerability has been resolved:
dma-buf: fix UAF in dma_buf_fd() tracepoint
Once FD_ADD() returns, the fd is live in the file descriptor table
and a thread sharing that table can close() it before DMA_BUF_TRACE()
runs. The close drops the last reference, __fput() frees the dma_buf,
and the tracepoint then dereferences dmabuf to take dmabuf->name_lock
-- slab-use-after-free.
Split FD_ADD() back into get_unused_fd_flags() + fd_install() and
emit the tracepoint between them. While the fdtable slot is reserved
with a NULL file pointer, a racing close() returns -EBADF without
entering __fput(), so the dma_buf stays alive across the trace. Same
approach as commit 2d76319c4cbb ("dma-buf: fix UAF in dma_buf_put()
tracepoint").
This undoes the FD_ADD() conversion done in commit 34dfce523c90
("dma: convert dma_buf_fd() to FD_ADD()"); FD_ADD() has no place to
hook the tracepoint safely. |
| In the Linux kernel, the following vulnerability has been resolved:
net: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer
In mana_hwc_rx_event_handler(), resp->response.hwc_msg_id is read from
DMA-coherent memory and bounds-checked, then mana_hwc_handle_resp()
re-reads the same field from the same DMA buffer for test_bit() and
pointer arithmetic.
DMA-coherent memory is mapped uncacheable on x86 and is shared,
unencrypted, in Confidential VMs (SEV-SNP/TDX), so each load goes
directly to host-visible memory. A H/W can modify the value
between the check and the use, bypassing the bounds validation.
Fix this by reading hwc_msg_id exactly once using READ_ONCE() into a
stack-local variable in mana_hwc_rx_event_handler(), and passing the
validated value as a parameter to mana_hwc_handle_resp(). |
| In the Linux kernel, the following vulnerability has been resolved:
parport: Fix race between port and client registration
The parport subsystem registers port devices before they are fully
initialised, resulting in a race condition where client drivers such
as lp can attach to ports that are not completely initialised or even
being torn down.
When the port and client drivers are built as modules and loaded
around the same time during boot, this occasionally results in a
crash. I was able to make this happen reliably in a VM with a
PC-style parallel port by patching parport_pc to fail probing:
> --- a/drivers/parport/parport_pc.c
> +++ b/drivers/parport/parport_pc.c
> @@ -2069,7 +2069,7 @@ static struct parport *__parport_pc_probe_port(unsigned long int base,
> if (!p)
> goto out3;
>
> - base_res = request_region(base, 3, p->name);
> + base_res = NULL;
> if (!base_res)
> goto out4;
>
and then running:
while true; do
modprobe lp & modprobe parport_pc
wait
rmmod lp parport_pc
done
for a few seconds.
In the long term I think port registration should be changed to put
the call to device_add() inside parport_announce_port(), but since the
latter currently cannot fail this will require changing all port
drivers.
For now, add a flag to indicate whether a port has been "announced"
and only try to attach client drivers to ports when the flag is set. |
| In the Linux kernel, the following vulnerability has been resolved:
netfs: Fix netfs_read_folio() to wait on writeback
Fix netfs_read_folio() to wait for an ongoing writeback to complete so that
it can trust the dirty flag and whatever is attached to folio->private
(folio->private may get cleaned up by the collector before it clears the
writeback flag). |
| In the Linux kernel, the following vulnerability has been resolved:
afs: Fix the locking used by afs_get_link()
The afs filesystem in the kernel doesn't do locking correctly for symbolic
links. There are a number of problems:
(1) It doesn't do any locking around afs_read_single() to prevent races
between multiple ->get_link() calls, thereby allowing the possibility
of leaks.
(2) It doesn't use RCU barriering when accessing the buffer pointers
during RCU pathwalk.
(3) It can race with another thread updating the contents of the symlink
if a third party updated it on the server.
Fix this by the following means:
(0) Move symlink handling into its own file as this makes it more
complicated.
(1) Take the validate_lock around afs_read_single() to prevent races
between multiple ->get_link() calls.
(2) Keep a separate copy of the symlink contents with an rcu_head. This
is always going to be a lot smaller than a page, so it can be
kmalloc'd and save quite a bit of memory. It also needs a refcount
for non-RCU pathwalk.
(3) Split the symlink read and write-to-cache routines in afs from those
for directories.
(4) Discard the I/O buffer as soon as the write-to-cache completes as this
is a full page (plus a folio_queue).
(5) If there's no cache, discard the I/O buffer immediately after reading
and copying if there is no cache. |
