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 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: Bluetooth: L2CAP: fix "bad unlock balance" in l2cap_disconnect_rsp conn->chan_lock isn't acquired before l2cap_get_chan_by_scid, if l2cap_get_chan_by_scid returns NULL, then 'bad unlock balance' is triggered.

CWE-832 - Unlock of a Resource that is not Locked

A flaw was found in the Linux kernel’s SCSI driver component qla2xxx (used with FCP-2 devices). When the terminate_rport_io() function is invoked , the driver may exit cleanup before all outstanding I/O operations have returned. This can lead to a use-after-free condition when resources are freed while I/Os are still pending.

CWE-416 - Use After Free

In the Linux kernel, the following vulnerability has been resolved: skbuff: skb_segment, Call zero copy functions before using skbuff frags Commit bf5c25d60861 ("skbuff: in skb_segment, call zerocopy functions once per nskb") added the call to zero copy functions in skb_segment(). The change introduced a bug in skb_segment() because skb_orphan_frags() may possibly change the number of fragments or allocate new fragments altogether leaving nrfrags and frag to point to the old values. This can cause a panic with stacktrace like the one below. [ 193.894380] BUG: kernel NULL pointer dereference, address: 00000000000000bc [ 193.895273] CPU: 13 PID: 18164 Comm: vh-net-17428 Kdump: loaded Tainted: G O 5.15.123+ #26 [ 193.903919] RIP: 0010:skb_segment+0xb0e/0x12f0 [ 194.021892] Call Trace: [ 194.027422] <TASK> [ 194.072861] tcp_gso_segment+0x107/0x540 [ 194.082031] inet_gso_segment+0x15c/0x3d0 [ 194.090783] skb_mac_gso_segment+0x9f/0x110 [ 194.095016] __skb_gso_segment+0xc1/0x190 [ 194.103131] netem_enqueue+0x290/0xb10 [sch_netem] [ 194.107071] dev_qdisc_enqueue+0x16/0x70 [ 194.110884] __dev_queue_xmit+0x63b/0xb30 [ 194.121670] bond_start_xmit+0x159/0x380 [bonding] [ 194.128506] dev_hard_start_xmit+0xc3/0x1e0 [ 194.131787] __dev_queue_xmit+0x8a0/0xb30 [ 194.138225] macvlan_start_xmit+0x4f/0x100 [macvlan] [ 194.141477] dev_hard_start_xmit+0xc3/0x1e0 [ 194.144622] sch_direct_xmit+0xe3/0x280 [ 194.147748] __dev_queue_xmit+0x54a/0xb30 [ 194.154131] tap_get_user+0x2a8/0x9c0 [tap] [ 194.157358] tap_sendmsg+0x52/0x8e0 [tap] [ 194.167049] handle_tx_zerocopy+0x14e/0x4c0 [vhost_net] [ 194.173631] handle_tx+0xcd/0xe0 [vhost_net] [ 194.176959] vhost_worker+0x76/0xb0 [vhost] [ 194.183667] kthread+0x118/0x140 [ 194.190358] ret_from_fork+0x1f/0x30 [ 194.193670] </TASK> In this case calling skb_orphan_frags() updated nr_frags leaving nrfrags local variable in skb_segment() stale. This resulted in the code hitting i >= nrfrags prematurely and trying to move to next frag_skb using list_skb pointer, which was NULL, and caused kernel panic. Move the call to zero copy functions before using frags and nr_frags.

CWE-476 - NULL Pointer Dereference

A buffer underwrite vulnerability exists in the linux kernel in the function skb_under_panic in ip6mr_cache_report(), leading to an attacker, via crafting a payload, could result in damage to system availability and integrity.

CWE-124 - Buffer Underwrite ('Buffer Underflow')

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: Fix potential use-after-free when clear keys Similar to commit c5d2b6fa26b5 ("Bluetooth: Fix use-after-free in hci_remove_ltk/hci_remove_irk"). We can not access k after kfree_rcu() call.

CWE-416 - Use After Free

A flaw use of uninitialized memory (uncontrolled and invisible by attacker) in the Linux kernel SCTP transport protocol was found in the way user triggers malicious SCTP packets. A remote user could use this flaw to crash the system. The bug actual only for systems where SCTP protocol being enabled and used.

CWE-664 - Improper Control of a Resource Through its Lifetime

In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: Validate UAC3 power domain descriptors, too UAC3 power domain descriptors need to be verified with its variable bLength for avoiding the unexpected OOB accesses by malicious firmware, too.

CWE-125 - Out-of-bounds Read

In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: Validate UAC3 cluster segment descriptors UAC3 class segment descriptors need to be verified whether their sizes match with the declared lengths and whether they fit with the allocated buffer sizes, too. Otherwise malicious firmware may lead to the unexpected OOB accesses.

CWE-20 - Improper Input Validation