Red Hat Security Advisory: kernel security update

Moderate

An out-of-bounds memory access vulnerability exists in the linux kernel, such that A stack-allocated buffer (backed by vmalloc) was passed into crypto code (scatterwalk_map_and_copy() → __memcpy) where a cross-page write occurred. This ended up hitting a read-only mapping, causing a page-level fault and kernel panic (Oops: 9600004f), potentially damaging system availability and stability.

CWE-119 - Improper Restriction of Operations within the Bounds of a Memory Buffer

A null pointer dereference exists in the linux kernel, such that when sfb_init() fails qdisc is NULL, and it will cause gpf issue, leading to damage to the availability of the system.

CWE-476 - NULL Pointer Dereference

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix user-after-free This uses l2cap_chan_hold_unless_zero() after calling __l2cap_get_chan_blah() to prevent the following trace: Bluetooth: l2cap_core.c:static void l2cap_chan_destroy(struct kref *kref) Bluetooth: chan 0000000023c4974d Bluetooth: parent 00000000ae861c08 ================================================================== BUG: KASAN: use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:191 [inline] BUG: KASAN: use-after-free in __mutex_lock_common kernel/locking/mutex.c:671 [inline] BUG: KASAN: use-after-free in __mutex_lock+0x278/0x400 kernel/locking/mutex.c:729 Read of size 8 at addr ffff888006a49b08 by task kworker/u3:2/389

A vulnerability was identified in the Linux kernel's ext4 filesystem implementation due to a flaw in how it processes filesystem metadata. An attacker with local privileges could create a malicious ext4 filesystem image to trigger this issue. When the system attempts to mount this malicious image, the kernel performs an incorrect calculation. This action results in unpredictable system behavior.

CWE-190 - Integer Overflow or Wraparound

In the Linux kernel, the following vulnerability has been resolved: NFSD: Protect against send buffer overflow in NFSv2 READ Since before the git era, NFSD has conserved the number of pages held by each nfsd thread by combining the RPC receive and send buffers into a single array of pages. This works because there are no cases where an operation needs a large RPC Call message and a large RPC Reply at the same time. Once an RPC Call has been received, svc_process() updates svc_rqst::rq_res to describe the part of rq_pages that can be used for constructing the Reply. This means that the send buffer (rq_res) shrinks when the received RPC record containing the RPC Call is large. A client can force this shrinkage on TCP by sending a correctly- formed RPC Call header contained in an RPC record that is excessively large. The full maximum payload size cannot be constructed in that case.

CWE-787 - Out-of-bounds Write