{"id":48675,"date":"2025-06-04T02:10:04","date_gmt":"2025-06-04T02:10:04","guid":{"rendered":""},"modified":"2025-09-07T05:20:12","modified_gmt":"2025-09-07T11:20:12","slug":"cve-2022-49753-critical-linux-kernel-vulnerability-in-dma-engine","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2022-49753-critical-linux-kernel-vulnerability-in-dma-engine\/","title":{"rendered":"<strong>CVE-2022-49753: Critical Linux Kernel Vulnerability in DMA Engine<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>A newly discovered vulnerability in the Linux kernel, CVE-2022-49753, concerns the DMA engine and may potentially lead to system compromise or data leakage if exploited. As the Linux kernel powers a vast variety of systems and devices worldwide, this vulnerability is significant and requires immediate attention. The flaw lies in the double increment of client_count in dma_chan_get(), which can lead to inappropriate freeing of channel resources.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2022-49753<br \/>\nSeverity: High (7.8 CVSS Score)<br \/>\nAttack Vector: Local<br \/>\nPrivileges Required: Low<br \/>\nUser Interaction: None<br \/>\nImpact: <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-32309-potential-system-compromise-due-to-remote-file-inclusion-in-php-program\/\"  data-wpil-monitor-id=\"56554\">System compromise<\/a> or data leakage<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-3970254760\" class=\"ameeb-content-2 ameeb-entity-placement\"><div style=\"border-left: 4px solid #555; padding-left: 20px; margin: 48px 0; font-family: Roboto, sans-serif; color: #ffffff; line-height: 1.6; max-width: 700px;\">\r\n  <h2 style=\"margin-top: 0; font-size: 20px; font-weight: 600; display: flex; align-items: center;\">\r\n    <a href=\"https:\/\/www.ameeba.com\/chat\" style=\"display: inline-flex; align-items: center; margin-right: 8px;\">\r\n      <img decoding=\"async\" src=\"https:\/\/www.ameeba.com\/blog\/wp-content\/uploads\/2025\/10\/Best-App-icon-Ameeba.png\" alt=\"Ameeba Chat Icon\" style=\"width: 40px; height: 40px;\" \/>\r\n    <\/a>\r\n    A new way to communicate\r\n  <\/h2>\r\n\r\n  <p style=\"margin-bottom: 12px;\">\r\n    Ameeba Chat is built on encrypted identity, not personal profiles.\r\n  <\/p>\r\n\r\n  <p style=\"margin-bottom: 16px;\">\r\n    Message, call, share files, and coordinate with identities kept separate.\r\n  <\/p>\r\n\r\n  <ul style=\"list-style: none; padding-left: 0; margin-bottom: 20px;\">\r\n    <li>\u2022 Encrypted identity<\/li>\r\n    <li>\u2022 Ameeba Chat authenticates access<\/li>\r\n    <li>\u2022 Aliases and categories<\/li>\r\n    <li>\u2022 End-to-end encrypted chat, calls, and files<\/li>\r\n    <li>\u2022 Secure notes for sensitive information<\/li>\r\n  <\/ul>\r\n\r\n  <p style=\"font-style: italic; font-weight: 600; margin-bottom: 24px;\">\r\n    Private communication, rethought.\r\n  <\/p>\r\n\r\n  <div style=\"display: flex; flex-wrap: wrap; gap: 12px;\">\r\n    <a href=\"https:\/\/www.ameeba.com\/chat\/download\" style=\"background-color: #ffffff; color: #000000; padding: 10px 20px; text-decoration: none; border-radius: 6px; font-weight: 500;\">Download Ameeba Chat<\/a>\r\n    <a href=\"https:\/\/www.ameeba.com\/chat\" style=\"border: 1px solid #ffffff; color: #ffffff; padding: 10px 20px; text-decoration: none; border-radius: 6px; font-weight: 500;\">Learn More<\/a>\r\n  <\/div>\r\n<\/div>\r\n<\/div>\n<p>Product | Affected Versions<\/p>\n<p><a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-21879-the-linux-kernel-btrfs-use-after-free-vulnerability\/\"  data-wpil-monitor-id=\"56553\">Linux Kernel<\/a> | 5.14.0-185.el9.x86_64 and earlier versions<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>The <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-48201-predictable-resource-location-vulnerability-in-typo3-s-ns-backup-extension\/\"  data-wpil-monitor-id=\"55617\">vulnerability is located<\/a> in the dmaengine subsystem of the Linux kernel. The dma_chan_get() function is responsible for handling DMA (Direct Memory Access) operations. When this function is called, it incorrectly increments the &#8220;client_count&#8221; twice for public channels. This can <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-47136-integer-underflow-vulnerability-in-indesign-desktop-versions-leading-to-potential-system-compromise\/\"  data-wpil-monitor-id=\"79768\">lead to an underflow<\/a> of the reference count of the DMA channel.<br \/>\nAs a result, the system mistakenly thinks that there are still clients using the channel when in fact, there are none. This can lead to the DMA channel&#8217;s resources not being freed when they should be, <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-22040-race-condition-vulnerability-in-linux-kernel-resulting-in-potential-system-compromise\/\"  data-wpil-monitor-id=\"57856\">resulting in potential<\/a> use-after-free scenarios.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-2748581778\" class=\"ameeb-content ameeb-entity-placement\"><div class=\"poptin-embedded\" data-id=\"f6b387694f681\"><\/div>\r\n\r\n\r\n\r\n\r\n\r\n<\/div>\n<p>While the exploit would require specific knowledge of the target <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2021-47668-linux-kernel-vulnerability-leading-to-potential-system-compromise-or-data-leakage\/\"  data-wpil-monitor-id=\"57518\">system&#8217;s configuration and would be executed at the kernel<\/a> level, it might conceptually look something like this:<\/p>\n<pre><code class=\"\" data-line=\"\">#include &lt;linux\/dmaengine.h&gt;\nvoid exploit_dma_vulnerability(void) {\nstruct dma_chan *chan;\n\/\/ Obtain a reference to a public DMA channel.\nchan = dma_find_channel(DMA_MEMCPY);\n\/\/ Call dma_chan_get() twice, incorrectly incrementing client count.\ndma_chan_get(chan);\ndma_chan_get(chan);\n\/\/ System now believes there are more clients using the channel than there are.\n\/\/ This can later result in a use-after-free situation when the channel&#039;s resources are not freed when they should be.\n}<\/code><\/pre>\n<p>Please note that this is a conceptual example and does not represent a usable exploit. It is provided for educational purposes only to help understand the nature of the vulnerability.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview A newly discovered vulnerability in the Linux kernel, CVE-2022-49753, concerns the DMA engine and may potentially lead to system compromise or data leakage if exploited. As the Linux kernel powers a vast variety of systems and devices worldwide, this vulnerability is significant and requires immediate attention. The flaw lies in the double increment of [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"footnotes":""},"categories":[1],"tags":[],"vendor":[88],"product":[95],"attack_vector":[],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-48675","post","type-post","status-publish","format-standard","hentry","category-uncategorized","vendor-linux","product-linux-kernel"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/48675","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/comments?post=48675"}],"version-history":[{"count":5,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/48675\/revisions"}],"predecessor-version":[{"id":72204,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/48675\/revisions\/72204"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=48675"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=48675"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=48675"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=48675"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=48675"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=48675"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=48675"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=48675"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=48675"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}