Уязвимость ядра операционных систем Linux, позволяющая нарушителю получить несанкционированный доступ к защищаемой информации

Уязвимость ядра операционной системы Linux, связанная с использованием памяти после её освобождения, позволяющая нарушителю раскрыть защищаемую информацию

Уязвимость ядра операционной системы Linux, позволяющая нарушителю повысить свои привилегии или получить несанкционированный доступ к защищаемой информации

Уязвимость функции can_optimize (arch/x86/kernel/kprobes/opt.c) ядра операционной системы Linux, позволяющая нарушителю оказать воздействие на конфиденциальность, целостность и доступность защищаемой информации

Уязвимость компонента drivers/infiniband/core/ucma.c ядра операционной системы Linux, позволяющая нарушителю получить доступ к конфиденциальным данным, нарушить их целостность, а также вызвать отказ в обслуживании

Уязвимость функции io_prep_async_work() подсистемы io_uring ядра операционной системы Linux, позволяющая нарушителю повысить свои привилегии

Уязвимость функции xt_replace_table() в модуле net/netfilter/x_tables.c межсетевого экрана netfilter ядра операционной системы Linux, позволяющая нарушителю оказать воздействие на конфиденциальность, целостность и доступность защищаемой информации

Уязвимость функции xen_free_irq() модуля drivers/xen/events/events_base.c гипервизора Xen ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании

Уязвимость компонента drivers/infiniband/core/iwcm.c ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании

Уязвимость функции qdisc_pkt_len_init() модуля net/core/dev.c ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании

A flaw was found in the Linux kernel. A use-after-free was found in the way the console subsystem was using ioctls KDGKBSENT and KDSKBSENT. A local user could use this flaw to get read memory access out of bounds. The highest threat from this vulnerability is to data confidentiality.

A flaw in ICMP packets in the Linux kernel may allow an attacker to quickly scan open UDP ports. This flaw allows an off-path remote attacker to effectively bypass source port UDP randomization. Software that relies on UDP source port randomization are indirectly affected as well on the Linux Based Products (RUGGEDCOM RM1224: All versions between v5.0 and v6.4, SCALANCE M-800: All versions between v5.0 and v6.4, SCALANCE S615: All versions between v5.0 and v6.4, SCALANCE SC-600: All versions prior to v2.1.3, SCALANCE W1750D: v8.3.0.1, v8.6.0, and v8.7.0, SIMATIC Cloud Connect 7: All versions, SIMATIC MV500 Family: All versions, SIMATIC NET CP 1243-1 (incl. SIPLUS variants): Versions 3.1.39 and later, SIMATIC NET CP 1243-7 LTE EU: Version

An issue was discovered in the Linux kernel through 5.10.1, as used with Xen through 4.14.x. The Linux kernel PV block backend expects the kernel thread handler to reset ring->xenblkd to NULL when stopped. However, the handler may not have time to run if the frontend quickly toggles between the states connect and disconnect. As a consequence, the block backend may re-use a pointer after it was freed. A misbehaving guest can trigger a dom0 crash by continuously connecting / disconnecting a block frontend. Privilege escalation and information leaks cannot be ruled out. This only affects systems with a Linux blkback.

An issue was discovered in the Linux kernel before 5.10. drivers/infiniband/core/ucma.c has a use-after-free because the ctx is reached via the ctx_list in some ucma_migrate_id situations where ucma_close is called, aka CID-f5449e74802c.

An issue was discovered in netfilter in the Linux kernel before 5.10. There can be a use-after-free in the packet processing context, because the per-CPU sequence count is mishandled during concurrent iptables rules replacement. This could be exploited with the CAP_NET_ADMIN capability in an unprivileged namespace. NOTE: cc00bca was reverted in 5.12.

A flaw was found in the Linux kernel in versions prior to 5.10. A violation of memory access was found while detecting a padding of int3 in the linking state. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

There is a logic error in io_uring's implementation which can be used to trigger a use-after-free vulnerability leading to privilege escalation. In the io_prep_async_work function the assumption that the last io_grab_identity call cannot return false is not true, and in this case the function will use the init_cred or the previous linked requests identity to do operations instead of using the current identity. This can lead to reference counting issues causing use-after-free. We recommend upgrading past version 5.10.161.

Closing of an event channel in the Linux kernel can result in a deadlock. This happens when the close is being performed in parallel to an unrelated Xen console action and the handling of a Xen console interrupt in an unprivileged guest. The closing of an event channel is e.g. triggered by removal of a paravirtual device on the other side. As this action will cause console messages to be issued on the other side quite often, the chance of triggering the deadlock is not neglectable. Note that 32-bit Arm-guests are not affected, as the 32-bit Linux kernel on Arm doesn't use queued-RW-locks, which are required to trigger the issue (on Arm32 a waiting writer doesn't block further readers to get the lock).

In the Linux kernel, the following vulnerability has been resolved: RDMA/iwcm: Fix WARNING:at_kernel/workqueue.c:#check_flush_dependency In the commit aee2424246f9 ("RDMA/iwcm: Fix a use-after-free related to destroying CM IDs"), the function flush_workqueue is invoked to flush the work queue iwcm_wq. But at that time, the work queue iwcm_wq was created via the function alloc_ordered_workqueue without the flag WQ_MEM_RECLAIM. Because the current process is trying to flush the whole iwcm_wq, if iwcm_wq doesn't have the flag WQ_MEM_RECLAIM, verify that the current process is not reclaiming memory or running on a workqueue which doesn't have the flag WQ_MEM_RECLAIM as that can break forward-progress guarantee leading to a deadlock. The call trace is as below: [ 125.350876][ T1430] Call Trace: [ 125.356281][ T1430] [ 125.361285][ T1430] ? __warn (kernel/panic.c:693) [ 125.367640][ T1430] ? check_flush_dependency (kernel/workqueue.c:3706 (discriminator 9)) [ 125.375689][ T1430] ? report_bug (lib/bug.c:180 lib/bug.c:219) [ 125.382505][ T1430] ? handle_bug (arch/x86/kernel/traps.c:239) [ 125.388987][ T1430] ? exc_invalid_op (arch/x86/kernel/traps.c:260 (discriminator 1)) [ 125.395831][ T1430] ? asm_exc_invalid_op (arch/x86/include/asm/idtentry.h:621) [ 125.403125][ T1430] ? check_flush_dependency (kernel/workqueue.c:3706 (discriminator 9)) [ 125.410984][ T1430] ? check_flush_dependency (kernel/workqueue.c:3706 (discriminator 9)) [ 125.418764][ T1430] __flush_workqueue (kernel/workqueue.c:3970) [ 125.426021][ T1430] ? __pfx___might_resched (kernel/sched/core.c:10151) [ 125.433431][ T1430] ? destroy_cm_id (drivers/infiniband/core/iwcm.c:375) iw_cm [ 125.441209][ T1430] ? __pfx___flush_workqueue (kernel/workqueue.c:3910) [ 125.473900][ T1430] ? _raw_spin_lock_irqsave (arch/x86/include/asm/atomic.h:107 include/linux/atomic/atomic-arch-fallback.h:2170 include/linux/atomic/atomic-instrumented.h:1302 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:111 kernel/locking/spinlock.c:162) [ 125.473909][ T1430] ? __pfx__raw_spin_lock_irqsave (kernel/locking/spinlock.c:161) [ 125.482537][ T1430] _destroy_id (drivers/infiniband/core/cma.c:2044) rdma_cm [ 125.495072][ T1430] nvme_rdma_free_queue (drivers/nvme/host/rdma.c:656 drivers/nvme/host/rdma.c:650) nvme_rdma [ 125.505827][ T1430] nvme_rdma_reset_ctrl_work (drivers/nvme/host/rdma.c:2180) nvme_rdma [ 125.505831][ T1430] process_one_work (kernel/workqueue.c:3231) [ 125.515122][ T1430] worker_thread (kernel/workqueue.c:3306 kernel/workqueue.c:3393) [ 125.515127][ T1430] ? __pfx_worker_thread (kernel/workqueue.c:3339) [ 125.531837][ T1430] kthread (kernel/kthread.c:389) [ 125.539864][ T1430] ? __pfx_kthread (kernel/kthread.c:342) [ 125.550628][ T1430] ret_from_fork (arch/x86/kernel/process.c:147) [ 125.558840][ T1430] ? __pfx_kthread (kernel/kthread.c:342) [ 125.558844][ T1430] ret_from_fork_asm (arch/x86/entry/entry_64.S:257) [ 125.566487][ T1430] [ 125.566488][ T1430] ---[ end trace 0000000000000000 ]---

In the Linux kernel, the following vulnerability has been resolved: net: avoid potential underflow in qdisc_pkt_len_init() with UFO After commit 7c6d2ecbda83 ("net: be more gentle about silly gso requests coming from user") virtio_net_hdr_to_skb() had sanity check to detect malicious attempts from user space to cook a bad GSO packet. Then commit cf9acc90c80ec ("net: virtio_net_hdr_to_skb: count transport header in UFO") while fixing one issue, allowed user space to cook a GSO packet with the following characteristic : IPv4 SKB_GSO_UDP, gso_size=3, skb->len = 28. When this packet arrives in qdisc_pkt_len_init(), we end up with hdr_len = 28 (IPv4 header + UDP header), matching skb->len Then the following sets gso_segs to 0 : gso_segs = DIV_ROUND_UP(skb->len - hdr_len, shinfo->gso_size); Then later we set qdisc_skb_cb(skb)->pkt_len to back to zero :/ qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len; This leads to the following crash in fq_codel [1] qdisc_pkt_len_init() is best effort, we only want an estimation of the bytes sent on the wire, not crashing the kernel. This patch is fixing this particular issue, a following one adds more sanity checks for another potential bug. [1] [ 70.724101] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 70.724561] #PF: supervisor read access in kernel mode [ 70.724561] #PF: error_code(0x0000) - not-present page [ 70.724561] PGD 10ac61067 P4D 10ac61067 PUD 107ee2067 PMD 0 [ 70.724561] Oops: Oops: 0000 [#1] SMP NOPTI [ 70.724561] CPU: 11 UID: 0 PID: 2163 Comm: b358537762 Not tainted 6.11.0-virtme #991 [ 70.724561] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 70.724561] RIP: 0010:fq_codel_enqueue (net/sched/sch_fq_codel.c:120 net/sched/sch_fq_codel.c:168 net/sched/sch_fq_codel.c:230) sch_fq_codel [ 70.724561] Code: 24 08 49 c1 e1 06 44 89 7c 24 18 45 31 ed 45 31 c0 31 ff 89 44 24 14 4c 03 8b 90 01 00 00 eb 04 39 ca 73 37 4d 8b 39 83 c7 01 <49> 8b 17 49 89 11 41 8b 57 28 45 8b 5f 34 49 c7 07 00 00 00 00 49 All code ======== 0: 24 08 and $0x8,%al 2: 49 c1 e1 06 shl $0x6,%r9 6: 44 89 7c 24 18 mov %r15d,0x18(%rsp) b: 45 31 ed xor %r13d,%r13d e: 45 31 c0 xor %r8d,%r8d 11: 31 ff xor %edi,%edi 13: 89 44 24 14 mov %eax,0x14(%rsp) 17: 4c 03 8b 90 01 00 00 add 0x190(%rbx),%r9 1e: eb 04 jmp 0x24 20: 39 ca cmp %ecx,%edx 22: 73 37 jae 0x5b 24: 4d 8b 39 mov (%r9),%r15 27: 83 c7 01 add $0x1,%edi 2a:* 49 8b 17 mov (%r15),%rdx <-- trapping instruction 2d: 49 89 11 mov %rdx,(%r9) 30: 41 8b 57 28 mov 0x28(%r15),%edx 34: 45 8b 5f 34 mov 0x34(%r15),%r11d 38: 49 c7 07 00 00 00 00 movq $0x0,(%r15) 3f: 49 rex.WB Code starting with the faulting instruction =========================================== 0: 49 8b 17 mov (%r15),%rdx 3: 49 89 11 mov %rdx,(%r9) 6: 41 8b 57 28 mov 0x28(%r15),%edx a: 45 8b 5f 34 mov 0x34(%r15),%r11d e: 49 c7 07 00 00 00 00 movq $0x0,(%r15) 15: 49 rex.WB [ 70.724561] RSP: 0018:ffff95ae85e6fb90 EFLAGS: 00000202 [ 70.724561] RAX: 0000000002000000 RBX: ffff95ae841de000 RCX: 0000000000000000 [ 70.724561] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 [ 70.724561] RBP: ffff95ae85e6fbf8 R08: 0000000000000000 R09: ffff95b710a30000 [ 70.724561] R10: 0000000000000000 R11: bdf289445ce31881 R12: ffff95ae85e6fc58 [ 70.724561] R13: 0000000000000000 R14: 0000000000000040 R15: 0000000000000000 [ 70.724561] FS: 000000002c5c1380(0000) GS:ffff95bd7fcc0000(0000) knlGS:0000000000000000 [ 70.724561] CS: 0010 DS: 0000 ES: 0000 C ---truncated---