Linux/Unix ホストには、ベンダーが提供するパッチが利用できない脆弱性の影響を受ける複数のパッケージがインストールされています。

  - Linux カーネルでは、以下の脆弱性が解決されています: xen/gntdev: Prevent leaking grants Prior to this commit, if a grant mapping operation failed partially, some of the entries in the map_ops array would be invalid, whereas all of the entries in the kmap_ops array would be valid. This in turn would cause the following logic in gntdev_map_grant_pages to become invalid: for (i = 0; i < map->count;
    i++) { if (map->map_ops[i].status == GNTST_okay) { map->unmap_ops[i].handle = map->map_ops[i].handle; if (!use_ptemod) alloced++; } if (use_ptemod) { if (map->kmap_ops[i].status == GNTST_okay) { if (map->map_ops[i].status == GNTST_okay) alloced++; map->kunmap_ops[i].handle = map->kmap_ops[i].handle; } }} ... atomic_add(alloced, &map->live_grants); Assume that use_ptemod is true (i.e., the domain mapping the granted pages is a paravirtualized domain). In the code excerpt above, note that the alloced variable is only incremented when both kmap_ops[i].status and map_ops[i].status are set to GNTST_okay (i.e., both mapping operations are successful). However, as also noted above, there are cases where a grant mapping operation fails partially, breaking the assumption of the code excerpt above. The aforementioned causes map->live_grants to be incorrectly set. In some cases, all of the map_ops mappings fail, but all of the kmap_ops mappings succeed, meaning that live_grants may remain zero. This in turn makes it impossible to unmap the successfully grant-mapped pages pointed to by kmap_ops, because unmap_grant_pages has the following snippet of code at its beginning: if (atomic_read(&map->live_grants) == 0) return; /* Nothing to do */ In other cases where only some of the map_ops mappings fail but all kmap_ops mappings succeed, live_grants is made positive, but when the user requests unmapping the grant-mapped pages,
    __unmap_grant_pages_done will then make map->live_grants negative, because the latter function does not check if all of the pages that were requested to be unmapped were actually unmapped, and the same function unconditionally subtracts data->count (i.e., a value that can be greater than map->live_grants) from map->live_grants. The side effects of a negative live_grants value have not been studied. The net effect of all of this is that grant references are leaked in one of the above conditions. In Qubes OS v4.1 (which uses Xen's grant mechanism extensively for X11 GUI isolation), this issue manifests itself with warning messages like the following to be printed out by the Linux kernel in the VM that had granted pages (that contain X11 GUI window data) to dom0: g.e. 0x1234 still pending, especially after the user rapidly resizes GUI VM windows (causing some grant-mapping operations to partially or completely fail, due to the fact that the VM unshares some of the pages as part of the window resizing, making the pages impossible to grant-map from dom0). The fix for this issue involves counting all successful map_ops and kmap_ops mappings separately, and then adding the sum to live_grants. During unmapping, only the number of successfully unmapped grants is subtracted from live_grants. The code is also modified to check for negative live_grants values after the subtraction and warn the user. (CVE-2022-50257)

Nessus は、ベンダーによって報告されたパッケージの存在に依存していることに注意してください。

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

  - In the Linux kernel, the following vulnerability has been resolved: xen/gntdev: Prevent leaking grants     Prior to this commit, if a grant mapping operation failed partially, some of the entries in the map_ops     array would be invalid, whereas all of the entries in the kmap_ops array would be valid. This in turn     would cause the following logic in gntdev_map_grant_pages to become invalid: for (i = 0; i < map->count;
    i++) { if (map->map_ops[i].status == GNTST_okay) { map->unmap_ops[i].handle = map->map_ops[i].handle; if     (!use_ptemod) alloced++; } if (use_ptemod) { if (map->kmap_ops[i].status == GNTST_okay) { if     (map->map_ops[i].status == GNTST_okay) alloced++; map->kunmap_ops[i].handle = map->kmap_ops[i].handle; } }     } ... atomic_add(alloced, &map->live_grants); Assume that use_ptemod is true (i.e., the domain mapping the     granted pages is a paravirtualized domain). In the code excerpt above, note that the alloced variable is     only incremented when both kmap_ops[i].status and map_ops[i].status are set to GNTST_okay (i.e., both     mapping operations are successful). However, as also noted above, there are cases where a grant mapping     operation fails partially, breaking the assumption of the code excerpt above. The aforementioned causes     map->live_grants to be incorrectly set. In some cases, all of the map_ops mappings fail, but all of the     kmap_ops mappings succeed, meaning that live_grants may remain zero. This in turn makes it impossible to     unmap the successfully grant-mapped pages pointed to by kmap_ops, because unmap_grant_pages has the     following snippet of code at its beginning: if (atomic_read(&map->live_grants) == 0) return; /* Nothing to     do */ In other cases where only some of the map_ops mappings fail but all kmap_ops mappings succeed,     live_grants is made positive, but when the user requests unmapping the grant-mapped pages,
    __unmap_grant_pages_done will then make map->live_grants negative, because the latter function does not     check if all of the pages that were requested to be unmapped were actually unmapped, and the same function     unconditionally subtracts data->count (i.e., a value that can be greater than map->live_grants) from     map->live_grants. The side effects of a negative live_grants value have not been studied. The net effect     of all of this is that grant references are leaked in one of the above conditions. In Qubes OS v4.1 (which     uses Xen's grant mechanism extensively for X11 GUI isolation), this issue manifests itself with warning     messages like the following to be printed out by the Linux kernel in the VM that had granted pages (that     contain X11 GUI window data) to dom0: g.e. 0x1234 still pending, especially after the user rapidly     resizes GUI VM windows (causing some grant-mapping operations to partially or completely fail, due to the     fact that the VM unshares some of the pages as part of the window resizing, making the pages impossible to     grant-map from dom0). The fix for this issue involves counting all successful map_ops and kmap_ops     mappings separately, and then adding the sum to live_grants. During unmapping, only the number of     successfully unmapped grants is subtracted from live_grants. The code is also modified to check for     negative live_grants values after the subtraction and warn the user. (CVE-2022-50257)

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

Linux/Unix 主機上安裝了一個或多個受到弱點影響的套件，且供應商未提供可用的修補程式。

  - 已解決 Linux 核心中的下列弱點：xen/gntdev: Prevent leaking grants Prior to this commit, if a grant mapping operation failed partially, some of the entries in the map_ops array would be invalid, whereas all of the entries in the kmap_ops array would be valid. This in turn would cause the following logic in gntdev_map_grant_pages to become invalid: for (i = 0; i < map->count;
    i++) { if (map->map_ops[i].status == GNTST_okay) { map->unmap_ops[i].handle = map->map_ops[i].handle; if (!use_ptemod) alloced++; } if (use_ptemod) { if (map->kmap_ops[i].status == GNTST_okay) { if (map->map_ops[i].status == GNTST_okay) alloced++; map->kunmap_ops[i].handle = map->kmap_ops[i].handle; } }} ... atomic_add(alloced, &map->live_grants); Assume that use_ptemod is true (i.e., the domain mapping the granted pages is a paravirtualized domain). In the code excerpt above, note that the alloced variable is only incremented when both kmap_ops[i].status and map_ops[i].status are set to GNTST_okay (i.e., both mapping operations are successful). However, as also noted above, there are cases where a grant mapping operation fails partially, breaking the assumption of the code excerpt above. The aforementioned causes map->live_grants to be incorrectly set. In some cases, all of the map_ops mappings fail, but all of the kmap_ops mappings succeed, meaning that live_grants may remain zero. This in turn makes it impossible to unmap the successfully grant-mapped pages pointed to by kmap_ops, because unmap_grant_pages has the following snippet of code at its beginning: if (atomic_read(&map->live_grants) == 0) return; /* Nothing to do */ In other cases where only some of the map_ops mappings fail but all kmap_ops mappings succeed, live_grants is made positive, but when the user requests unmapping the grant-mapped pages,
    __unmap_grant_pages_done will then make map->live_grants negative, because the latter function does not check if all of the pages that were requested to be unmapped were actually unmapped, and the same function unconditionally subtracts data->count (i.e., a value that can be greater than map->live_grants) from map->live_grants. The side effects of a negative live_grants value have not been studied. The net effect of all of this is that grant references are leaked in one of the above conditions. In Qubes OS v4.1 (which uses Xen's grant mechanism extensively for X11 GUI isolation), this issue manifests itself with warning messages like the following to be printed out by the Linux kernel in the VM that had granted pages (that contain X11 GUI window data) to dom0: g.e. 0x1234 still pending, especially after the user rapidly resizes GUI VM windows (causing some grant-mapping operations to partially or completely fail, due to the fact that the VM unshares some of the pages as part of the window resizing, making the pages impossible to grant-map from dom0). The fix for this issue involves counting all successful map_ops and kmap_ops mappings separately, and then adding the sum to live_grants. During unmapping, only the number of successfully unmapped grants is subtracted from live_grants. The code is also modified to check for negative live_grants values after the subtraction and warn the user. (CVE-2022-50257)

請注意，Nessus 依賴供應商報告的套件存在。

Linux/Unix 主机中安装的一个或多个程序包受到一个漏洞影响，而供应商没有提供补丁程序。

  - 已修复 Linux 内核中的下列漏洞：xen/gntdev: Prevent leaking grants Prior to this commit, if a grant mapping operation failed partially, some of the entries in the map_ops array would be invalid, whereas all of the entries in the kmap_ops array would be valid. This in turn would cause the following logic in gntdev_map_grant_pages to become invalid: for (i = 0; i < map->count;
    i++) { if (map->map_ops[i].status == GNTST_okay) { map->unmap_ops[i].handle = map->map_ops[i].handle; if (!use_ptemod) alloced++; } if (use_ptemod) { if (map->kmap_ops[i].status == GNTST_okay) { if (map->map_ops[i].status == GNTST_okay) alloced++; map->kunmap_ops[i].handle = map->kmap_ops[i].handle; } }} ... atomic_add(alloced, &map->live_grants); Assume that use_ptemod is true (i.e., the domain mapping the granted pages is a paravirtualized domain). In the code excerpt above, note that the alloced variable is only incremented when both kmap_ops[i].status and map_ops[i].status are set to GNTST_okay (i.e., both mapping operations are successful). However, as also noted above, there are cases where a grant mapping operation fails partially, breaking the assumption of the code excerpt above. The aforementioned causes map->live_grants to be incorrectly set. In some cases, all of the map_ops mappings fail, but all of the kmap_ops mappings succeed, meaning that live_grants may remain zero. This in turn makes it impossible to unmap the successfully grant-mapped pages pointed to by kmap_ops, because unmap_grant_pages has the following snippet of code at its beginning: if (atomic_read(&map->live_grants) == 0) return; /* Nothing to do */ In other cases where only some of the map_ops mappings fail but all kmap_ops mappings succeed, live_grants is made positive, but when the user requests unmapping the grant-mapped pages,
    __unmap_grant_pages_done will then make map->live_grants negative, because the latter function does not check if all of the pages that were requested to be unmapped were actually unmapped, and the same function unconditionally subtracts data->count (i.e., a value that can be greater than map->live_grants) from map->live_grants. The side effects of a negative live_grants value have not been studied. The net effect of all of this is that grant references are leaked in one of the above conditions. In Qubes OS v4.1 (which uses Xen's grant mechanism extensively for X11 GUI isolation), this issue manifests itself with warning messages like the following to be printed out by the Linux kernel in the VM that had granted pages (that contain X11 GUI window data) to dom0: g.e. 0x1234 still pending, especially after the user rapidly resizes GUI VM windows (causing some grant-mapping operations to partially or completely fail, due to the fact that the VM unshares some of the pages as part of the window resizing, making the pages impossible to grant-map from dom0). The fix for this issue involves counting all successful map_ops and kmap_ops mappings separately, and then adding the sum to live_grants. During unmapping, only the number of successfully unmapped grants is subtracted from live_grants. The code is also modified to check for negative live_grants values after the subtraction and warn the user. (CVE-2022-50257)

请注意，Nessus 依赖供应商报告的程序包是否存在进行判断。

ID	名称	产品	系列	发布时间	最近更新时间	严重程度
265143	Linux Distros のパッチ未適用の脆弱性: CVE-2022-50257	Nessus	Misc.	2025/9/17	2025/9/30	high
265143	Linux Distros Unpatched Vulnerability : CVE-2022-50257	Nessus	Misc.	2025/9/17	2025/9/30	high
265143	Linux Distros 未修補的弱點：CVE-2022-50257	Nessus	Misc.	2025/9/17	2025/9/30	high
265143	Linux Distros 未修补的漏洞：CVE-2022-50257	Nessus	Misc.	2025/9/17	2025/9/30	high

检测

插件搜索

high

high

high

high