{"id":66894,"date":"2025-07-28T17:33:48","date_gmt":"2025-07-28T14:03:48","guid":{"rendered":"https:\/\/afaghhosting.net\/blog\/cve-2025-38493-linux-kernel-fortify_source-buffer-overflow-in-timerlat_dump_stack\/"},"modified":"2025-07-28T17:33:48","modified_gmt":"2025-07-28T14:03:48","slug":"cve-2025-38493-linux-kernel-fortify_source-buffer-overflow-in-timerlat_dump_stack","status":"publish","type":"post","link":"https:\/\/afaghhosting.net\/blog\/cve-2025-38493-linux-kernel-fortify_source-buffer-overflow-in-timerlat_dump_stack\/","title":{"rendered":"CVE-2025-38493 &#8211; Linux Kernel FORTIFY_SOURCE Buffer Overflow in timerlat_dump_stack"},"content":{"rendered":"<p><strong>CVE ID : <\/strong>CVE-2025-38493<br \/>\n<br \/>\n<strong>Published : <\/strong> July 28, 2025, 12:15 p.m. | 1\u00a0hour, 5\u00a0minutes ago<br \/>\n<br \/>\n<strong>Description : <\/strong>In the Linux kernel, the following vulnerability has been resolved:<\/p>\n<p>tracing\/osnoise: Fix crash in timerlat_dump_stack()<\/p>\n<p>We have observed kernel panics when using timerlat with stack saving,<br \/>\nwith the following dmesg output:<\/p>\n<p>memcpy: detected buffer overflow: 88 byte write of buffer size 0<br \/>\nWARNING: CPU: 2 PID: 8153 at lib\/string_helpers.c:1032 __fortify_report+0x55\/0xa0<br \/>\nCPU: 2 UID: 0 PID: 8153 Comm: timerlatu\/2 Kdump: loaded Not tainted 6.15.3-200.fc42.x86_64 #1 PREEMPT(lazy)<br \/>\nCall Trace:<\/p>\n<p> ? trace_buffer_lock_reserve+0x2a\/0x60<br \/>\n __fortify_panic+0xd\/0xf<br \/>\n __timerlat_dump_stack.cold+0xd\/0xd<br \/>\n timerlat_dump_stack.part.0+0x47\/0x80<br \/>\n timerlat_fd_read+0x36d\/0x390<br \/>\n vfs_read+0xe2\/0x390<br \/>\n ? syscall_exit_to_user_mode+0x1d5\/0x210<br \/>\n ksys_read+0x73\/0xe0<br \/>\n do_syscall_64+0x7b\/0x160<br \/>\n ? exc_page_fault+0x7e\/0x1a0<br \/>\n entry_SYSCALL_64_after_hwframe+0x76\/0x7e<\/p>\n<p>__timerlat_dump_stack() constructs the ftrace stack entry like this:<\/p>\n<p>struct stack_entry *entry;<br \/>\n&#8230;<br \/>\nmemcpy(&amp;entry-&gt;caller, fstack-&gt;calls, size);<br \/>\nentry-&gt;size = fstack-&gt;nr_entries;<\/p>\n<p>Since commit e7186af7fb26 (&#8220;tracing: Add back FORTIFY_SOURCE logic to<br \/>\nkernel_stack event structure&#8221;), struct stack_entry marks its caller<br \/>\nfield with __counted_by(size). At the time of the memcpy, entry-&gt;size<br \/>\ncontains garbage from the ringbuffer, which under some circumstances is<br \/>\nzero, triggering a kernel panic by buffer overflow.<\/p>\n<p>Populate the size field before the memcpy so that the out-of-bounds<br \/>\ncheck knows the correct size. This is analogous to<br \/>\n__ftrace_trace_stack().<br \/>\n<br \/>\n<strong>Severity:<\/strong> 0.0 | NA<br \/>\n<br \/>\nVisit the link for more details, such as CVSS details, affected products, timeline, and more&#8230;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>CVE ID : CVE-2025-38493 Published : July 28, 2025, 12:15 p.m. | 1\u00a0hour, 5\u00a0minutes ago Description : In the Linux kernel, the following vulnerability has been resolved: tracing\/osnoise: Fix crash in timerlat_dump_stack() We have observed kernel panics when using timerlat with stack saving, with the following dmesg output: memcpy: detected buffer overflow: 88 byte write &hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[26],"tags":[],"class_list":["post-66894","post","type-post","status-publish","format-standard","hentry","category-vulnerability"],"_links":{"self":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/66894","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/comments?post=66894"}],"version-history":[{"count":0,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/66894\/revisions"}],"wp:attachment":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/media?parent=66894"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/categories?post=66894"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/tags?post=66894"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}