{"id":"AZL-67037","summary":"CVE-2025-39683 affecting package kernel for versions less than 6.6.104.2-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Limit access to parser-\u003ebuffer when trace_get_user failed\n\nWhen the length of the string written to set_ftrace_filter exceeds\nFTRACE_BUFF_MAX, the following KASAN alarm will be triggered:\n\nBUG: KASAN: slab-out-of-bounds in strsep+0x18c/0x1b0\nRead of size 1 at addr ffff0000d00bd5ba by task ash/165\n\nCPU: 1 UID: 0 PID: 165 Comm: ash Not tainted 6.16.0-g6bcdbd62bd56-dirty\nHardware name: linux,dummy-virt (DT)\nCall trace:\n show_stack+0x34/0x50 (C)\n dump_stack_lvl+0xa0/0x158\n print_address_description.constprop.0+0x88/0x398\n print_report+0xb0/0x280\n kasan_report+0xa4/0xf0\n __asan_report_load1_noabort+0x20/0x30\n strsep+0x18c/0x1b0\n ftrace_process_regex.isra.0+0x100/0x2d8\n ftrace_regex_release+0x484/0x618\n __fput+0x364/0xa58\n ____fput+0x28/0x40\n task_work_run+0x154/0x278\n do_notify_resume+0x1f0/0x220\n el0_svc+0xec/0xf0\n el0t_64_sync_handler+0xa0/0xe8\n el0t_64_sync+0x1ac/0x1b0\n\nThe reason is that trace_get_user will fail when processing a string\nlonger than FTRACE_BUFF_MAX, but not set the end of parser-\u003ebuffer to 0.\nThen an OOB access will be triggered in ftrace_regex_release-\u003e\nftrace_process_regex-\u003estrsep-\u003estrpbrk. We can solve this problem by\nlimiting access to parser-\u003ebuffer when trace_get_user failed.","modified":"2026-04-01T05:21:06.908693Z","published":"2025-09-05T18:15:44Z","upstream":["CVE-2025-39683"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-39683"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.104.2-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-67037.json"}}],"schema_version":"1.7.5"}