In the Linux kernel, the following vulnerability has been resolved: blk-iolatency: Fix memory leak on add_disk() failures When a gendisk is successfully initialized but add_disk() fails such as when a loop device has invalid number of minor device numbers specified, blkcg_init_disk() is called during init and then blkcg_exit_disk() during error handling. Unfortunately, iolatency gets initialized in the former but doesn't get cleaned up in the latter. This is because, in non-error cases, the cleanup is performed by del_gendisk() calling rq_qos_exit(), the assumption being that rq_qos policies, iolatency being one of them, can only be activated once the disk is fully registered and visible. That assumption is true for wbt and iocost, but not so for iolatency as it gets initialized before add_disk() is called. It is desirable to lazy-init rq_qos policies because they are optional features and add to hot path overhead once initialized - each IO has to walk all the registered rq_qos policies. So, we want to switch iolatency to lazy init too. However, that's a bigger change. As a fix for the immediate problem, let's just add an extra call to rq_qos_exit() in blkcg_exit_disk(). This is safe because duplicate calls to rq_qos_exit() become noop's.

The AlmaLinux 9.2 host has packages installed that are affected by multiple vulnerabilities as referenced in the TuxCare ALMALINUX9.2:CLSA-2026:1791741836 advisory.

  - In the Linux kernel, the following vulnerability has been resolved: vhost: fix hung thread due to     erroneous iotlb entries In vhost_iotlb_add_range_ctx(), range size can overflow to 0 when start is 0 and     last is ULONG_MAX. One instance where it can happen is when userspace sends an IOTLB message with     iova=size=uaddr=0 (vhost_process_iotlb_msg). So, an entry with size = 0, start = 0, last = ULONG_MAX ends     up in the iotlb. Next time a packet is sent, iotlb_access_ok() loops indefinitely due to that erroneous     entry. Call Trace: <TASK> iotlb_access_ok+0x21b/0x3e0 drivers/vhost/vhost.c:1340     vq_meta_prefetch+0xbc/0x280 drivers/vhost/vhost.c:1366 vhost_transport_do_send_pkt+0xe0/0xfd0     drivers/vhost/vsock.c:104 vhost_worker+0x23d/0x3d0 drivers/vhost/vhost.c:372 kthread+0x2e9/0x3a0     kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 </TASK> Reported by syzbot at:
    https://syzkaller.appspot.com/bug?extid=0abd373e2e50d704db87 To fix this, do two things: 1. Return -EINVAL     in vhost_chr_write_iter() when userspace asks to map a range with size 0. 2. Fix     vhost_iotlb_add_range_ctx() to handle the range [0, ULONG_MAX] by splitting it into two entries.
    (CVE-2022-48862)

  - In the Linux kernel, the following vulnerability has been resolved: net: hns3: add vlan list lock to     protect vlan list When adding port base VLAN, vf VLAN need to remove from HW and modify the vlan state in     vf VLAN list as false. If the periodicity task is freeing the same node, it may cause use after free     error. This patch adds a vlan list lock to protect the vlan list. (CVE-2022-49182)

  - In the Linux kernel, the following vulnerability has been resolved: perf/x86/amd: Fix crash due to race     between amd_pmu_enable_all, perf NMI and throttling amd_pmu_enable_all() does: if (!test_bit(idx,     cpuc->active_mask)) continue; amd_pmu_enable_event(cpuc->events[idx]); A perf NMI of another event can     come between these two steps. Perf NMI handler internally disables and enables _all_ events, including the     one which nmi-intercepted amd_pmu_enable_all() was in process of enabling. If that unintentionally enabled     event has very low sampling period and causes immediate successive NMI, causing the event to be throttled,     cpuc->events[idx] and cpuc->active_mask gets cleared by x86_pmu_stop(). This will result in     amd_pmu_enable_event() getting called with event=NULL when amd_pmu_enable_all() resumes after handling the     NMIs. This causes a kernel crash: BUG: kernel NULL pointer dereference, address: 0000000000000198 #PF:
    supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page [...] Call Trace: <TASK>     amd_pmu_enable_all+0x68/0xb0 ctx_resched+0xd9/0x150 event_function+0xb8/0x130 ?     hrtimer_start_range_ns+0x141/0x4a0 ? perf_duration_warn+0x30/0x30 remote_function+0x4d/0x60
    __flush_smp_call_function_queue+0xc4/0x500 flush_smp_call_function_queue+0x11d/0x1b0 do_idle+0x18f/0x2d0     cpu_startup_entry+0x19/0x20 start_secondary+0x121/0x160 secondary_startup_64_no_verify+0xe5/0xeb </TASK>     amd_pmu_disable_all()/amd_pmu_enable_all() calls inside perf NMI handler were recently added as part of     BRS enablement but I'm not sure whether we really need them. We can just disable BRS in the beginning and     enable it back while returning from NMI. This will solve the issue by not enabling those events whose     active_masks are set but are not yet enabled in hw pmu. (CVE-2022-49781)

  - In the Linux kernel, the following vulnerability has been resolved: blk-iolatency: Fix memory leak on     add_disk() failures When a gendisk is successfully initialized but add_disk() fails such as when a loop     device has invalid number of minor device numbers specified, blkcg_init_disk() is called during init and     then blkcg_exit_disk() during error handling. Unfortunately, iolatency gets initialized in the former but     doesn't get cleaned up in the latter. This is because, in non-error cases, the cleanup is performed by     del_gendisk() calling rq_qos_exit(), the assumption being that rq_qos policies, iolatency being one of     them, can only be activated once the disk is fully registered and visible. That assumption is true for wbt     and iocost, but not so for iolatency as it gets initialized before add_disk() is called. It is desirable     to lazy-init rq_qos policies because they are optional features and add to hot path overhead once     initialized - each IO has to walk all the registered rq_qos policies. So, we want to switch iolatency to     lazy init too. However, that's a bigger change. As a fix for the immediate problem, let's just add an     extra call to rq_qos_exit() in blkcg_exit_disk(). This is safe because duplicate calls to rq_qos_exit()     become noop's. (CVE-2022-50550)

  - In the Linux kernel, the following vulnerability has been resolved: usb: roles: fix NULL pointer issue     when put module's reference In current design, usb role class driver will get usb_role_switch parent's     module reference after the user get usb_role_switch device and put the reference after the user put the     usb_role_switch device. However, the parent device of usb_role_switch may be removed before the user put     the usb_role_switch. If so, then, NULL pointer issue will be met when the user put the parent module's     reference. This will save the module pointer in structure of usb_role_switch. Then, we don't need to find     module by iterating long relations. (CVE-2024-26747)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - blk-iolatency: Fix memory leak on add_disk() failures When a gendisk is successfully initialized but     add_disk() fails such as when a loop device has invalid number of minor device numbers specified,     blkcg_init_disk() is called during init and then blkcg_exit_disk() during error handling. Unfortunately,     iolatency gets initialized in the former but doesn't get cleaned up in the latter. This is because, in     non-error cases, the cleanup is performed by del_gendisk() calling rq_qos_exit(), the assumption being     that rq_qos policies, iolatency being one of them, can only be activated once the disk is fully registered     and visible. That assumption is true for wbt and iocost, but not so for iolatency as it gets initialized     before add_disk() is called. It is desirable to lazy-init rq_qos policies because they are optional     features and add to hot path overhead once initialized - each IO has to walk all the registered rq_qos     policies. So, we want to switch iolatency to lazy init too. However, that's a bigger change. As a fix for     the immediate problem, let's just add an extra call to rq_qos_exit() in blkcg_exit_disk(). This is safe     because duplicate calls to rq_qos_exit() become noop's. (CVE-2022-50550)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
364688	AlmaLinux 9.2 [TuxCare] Security Update: bpftool / kernel / kernel-64k / kernel-64k-core / kernel-64k-debug / etc Multiple Vulnerabilities (ALMALINUX9.2:CLSA-2026:1791741836)	Nessus	Alma Linux Local Security Checks	Local	critical
269268	Linux Distros Unpatched Vulnerability : CVE-2022-50550	Nessus	Misc.	Local	medium

Detections

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CVE-2022-50550

medium

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critical

medium