In the Linux kernel, the following vulnerability has been resolved:
libceph: Fix slab-out-of-bounds access in auth message processing
If a (potentially corrupted) message of type CEPH_MSG_AUTH_REPLY
contains a positive value in its result field, it is treated as an
error code by ceph_handle_auth_reply() and returned to
handle_auth_reply(). Thereafter, an attempt is made to send the
preallocated message of type CEPH_MSG_AUTH, where the returned value is
interpreted as the size of the front segment to send. If the result
value in the message is greater than the size of the memory buffer
allocated for the front segment, an out-of-bounds access occurs, and
the content of the memory region beyond this buffer is sent out.
This patch fixes the issue by treating only negative values in the
result field as errors. Positive values are therefore treated as success
in the same way as a zero value. Additionally, a BUG_ON is added to
__send_prepared_auth_request() comparing the len parameter to
front_alloc_len to prevent sending the message if it exceeds the bounds
of the allocation and to make it easier to catch any logic flaws leading
to this.
In the Linux kernel, the following vulnerability has been resolved:
ip6_gre: Use cached t->net in ip6erspan_changelink().
After commit 5e72ce3e3980 ("net: ipv6: Use link netns in newlink() of
rtnl_link_ops"), ip6erspan_newlink() correctly resolves the per-netns
ip6gre hash via link_net. ip6erspan_changelink() was not converted in
that series and still uses dev_net(dev), which diverges from the
device's creation netns after IFLA_NET_NS_FD migration.
This re-inserts the tunnel into the wrong per-netns hash. The
original netns keeps a stale entry. When that netns is later
destroyed, ip6gre_exit_rtnl_net() walks the stale entry, producing a
slab-use-after-free reported by KASAN, followed by a kernel BUG at
net/core/dev.c (LIST_POISON1) in unregister_netdevice_many_notify().
Reachable from an unprivileged user namespace (unshare --user
--map-root-user --net).
ip6gre_changelink() earlier in the same file already uses the cached
t->net; only ip6erspan_changelink() has the wrong shape.
In the Linux kernel, the following vulnerability has been resolved:
wifi: b43: enforce bounds check on firmware key index in b43_rx()
The firmware-controlled key index in b43_rx() can exceed the dev->key[]
array size (58 entries). The existing B43_WARN_ON is non-enforcing in
production builds, allowing an out-of-bounds read.
Make the B43_WARN_ON check enforcing by dropping the frame when the
firmware returns an invalid key index.
In the Linux kernel, the following vulnerability has been resolved:
dm-thin: fix metadata refcount underflow
There's a bug in dm-thin in the function rebalance_children. If the
internal btree node has one entry, the code tries to copy all btree
entries from the node's child to the node itself and then decrement the
child's reference count.
If the child node is shared (it has reference count > 1), we won't free
it, so there would be two pointers to each of the grandchildren nodes.
But the reference counts of the grandchildren is not increased, thus the
reference count doesn't match the number of pointers that point to the
grandchildren. This results in "device mapper: space map common: unable
to decrement block" errors.
Fix this bug by incrementing reference counts on the grandchildren if the
btree node is shared.
In the Linux kernel, the following vulnerability has been resolved:
ipmi:si: Return state to normal if message allocation fails
There were places where nothing would get started if a message
allocation failed, so the driver needs to return to normal state.
In the Linux kernel, the following vulnerability has been resolved:
RDMA/hns: Fix unlocked call to hns_roce_qp_remove()
Sashiko points out that hns_roce_qp_remove() requires the caller to hold
locks. The error flow in hns_roce_create_qp_common() doesn't hold those
locks for the error unwind so it risks corrupting memory.
Grab the same locks the other two callers use.
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Fix shadow paging use-after-free due to unexpected GFN
The shadow MMU computes GFNs for direct shadow pages using sp->gfn plus
the SPTE index. This assumption breaks for shadow paging if the guest
page tables are modified between VM entries (similar to commit
aad885e77496, "KVM: x86/mmu: Drop/zap existing present SPTE even
when creating an MMIO SPTE", 2026-03-27). The flow is as follows:
- a PDE is installed for a 2MB mapping, and a page in that area is
accessed. KVM creates a kvm_mmu_page consisting of 512 4KB pages;
the kvm_mmu_page is marked by FNAME(fetch) as direct-mapped because
the guest's mapping is a huge page (and thus contiguous).
- the PDE mapping is changed from outside the guest.
- the guest accesses another page in the same 2MB area. KVM installs
a new leaf SPTE and rmap entry; the SPTE uses the "correct" GFN
(i.e. based on the new mapping, as changed in the previous step) but
that GFN is outside of the [sp->gfn, sp->gfn + 511] range; therefore
the rmap entry cannot be found and removed when the kvm_mmu_page
is zapped.
- the memslot that covers the first 2MB mapping is deleted, and the
kvm_mmu_page for the now-invalid GPA is zapped. However, rmap_remove()
only looks at the [sp->gfn, sp->gfn + 511] range established in step 1,
and fails to find the rmap entry that was recorded by step 3.
- any operation that causes an rmap walk for the same page accessed
by step 3 then walks a stale rmap and dereferences a freed kvm_mmu_page.
This includes dirty logging or MMU notifier invalidations (e.g., from
MADV_DONTNEED).
The underlying issue is that KVM's walking of shadow PTEs assumes that
if a SPTE is present when KVM wants to install a non-leaf SPTE, then the
existing kvm_mmu_page must be for the correct gfn. Because the only way
for the gfn to be wrong is if KVM messed up and failed to zap a SPTE...
which shouldn't happen, but *actually* only happens in response to a
guest write.
That bug dates back literally forever, as even the first version of KVM
assumes that the GFN matches and walks into the "wrong" shadow page.
However, that was only an imprecision until 2032a93d66fa ("KVM: MMU:
Don't allocate gfns page for direct mmu pages") came along.
Fix it by checking for a target gfn mismatch and zapping the existing
SPTE. That way the old SP and rmap entries are gone, KVM installs
the rmap in the right location, and everyone is happy.
In the Linux kernel, the following vulnerability has been resolved:
net: strparser: fix skb_head leak in strp_abort_strp()
When the stream parser is aborted, for example after a message assembly timeout,
it can still hold a reference to a partially assembled message in
strp->skb_head.
That skb is not released in strp_abort_strp(), which leaks the partially
assembled message and can be triggered repeatedly to exhaust memory.
Fix this by freeing strp->skb_head and resetting the parser state in the
abort path. Leave strp_stop() unchanged so final cleanup still happens in
strp_done() after the work and timer have been synchronized.
In the Linux kernel, the following vulnerability has been resolved:
can: ucan: fix devres lifetime
USB drivers bind to USB interfaces and any device managed resources
should have their lifetime tied to the interface rather than parent USB
device. This avoids issues like memory leaks when drivers are unbound
without their devices being physically disconnected (e.g. on probe
deferral or configuration changes).
Fix the control message buffer lifetime so that it is released on driver
unbind.
In the Linux kernel, the following vulnerability has been resolved:
net: caif: clear client service pointer on teardown
`caif_connect()` can tear down an existing client after remote shutdown by
calling `caif_disconnect_client()` followed by `caif_free_client()`.
`caif_free_client()` releases the service layer referenced by
`adap_layer->dn`, but leaves that pointer stale.
When the socket is later destroyed, `caif_sock_destructor()` calls
`caif_free_client()` again and dereferences the freed service pointer.
Clear the client/service links before releasing the service object so
repeated teardown becomes harmless.