{"schema":"threatline.record/2","record":{"id":"CVE-2026-97937","aliases":[],"summary":"ftrace: fork: Initialize function graph state before copy_exec_state()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nftrace: fork: Initialize function graph state before copy_exec_state()\n\ndup_task_struct() copies the parent's task_struct, including ret_stack.\nftrace_graph_init_task() clears the copied function graph state, but it\ncurrently runs after copy_exec_state().\n\nFor non-CLONE_VM forks, copy_exec_state() allocates a new task_exec_state.\nIf that allocation fails, copy_process() reaches bad_fork_free and\nfree_task() calls ftrace_graph_exit_task(). Since the child still carries\nthe parent's ret_stack pointer, the unwind frees the parent's active\nfunction graph return stack. The parent subsequently accesses freed memory\nfrom function_graph_enter_regs().\n\nKASAN reports:\n\n[   22.190920] ==================================================================\n[   22.195899] BUG: KASAN: slab-use-after-free in function_graph_enter_regs+0xa76/0xb90\n[   22.200747] Write of size 8 at addr ff110000054dc0a8 by task repro/1\n[   22.205134]\n[   22.210770] CPU: 0 UID: 0 PID: 1 Comm: repro Not tainted 7.2.0-07732-g9328b3b03bdc-dirty #3 PREEMPT(lazy)\n[   22.212576] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n[   22.213750] Call Trace:\n[   22.215271]  <TASK>\n[   22.216242]  ? ftrace_stub_direct_tramp+0x10/0x10\n[   22.217774]  dump_stack_lvl+0x4e/0x70\n[   22.220531]  print_report+0x157/0x4b4\n[   22.223202]  ? fixup_red_left+0x9/0x30\n[   22.224407]  ? complete_report_info+0x83/0x110\n[   22.226679]  ? function_graph_enter_regs+0xa76/0xb90\n[   22.228084]  kasan_report+0xce/0x100\n[   22.230109]  ? function_graph_enter_regs+0xa76/0xb90\n[   22.232860]  ? stack_trace_save+0x4/0xd0\n[   22.234156]  function_graph_enter_regs+0xa76/0xb90\n[   22.236090]  ? kasan_save_stack+0x30/0x50\n[   22.237752]  ? __pfx_function_graph_enter_regs+0x10/0x10\n[   22.238694]  ? ring_buffer_lock_reserve+0x345/0xf80\n[   22.239628]  ? stack_trace_save+0x4/0xd0\n[   22.242121]  ? stack_trace_save+0x4/0xd0\n[   22.243588]  ftrace_graph_func+0xda/0x160\n[   22.245362]  ? ftrace_stub_direct_tramp+0x10/0x10\n[   22.246520]  0xffffffffa0000095\n[   22.250528]  ? stack_trace_save+0x9/0xd0\n[   22.251757]  ? ring_buffer_unlock_commit+0x11d/0x5c0\n[   22.253152]  stack_trace_save+0x9/0xd0\n[   22.254264]  kasan_save_stack+0x30/0x50\n[   22.273631]  kasan_save_track+0x14/0x30\n[   22.276763]  kasan_save_free_info+0x3b/0x70\n[   22.278296]  __kasan_slab_free+0x43/0x70\n[   22.280157]  kmem_cache_free+0xbf/0x3b0\n[   22.282963]  ? ftrace_stub_direct_tramp+0x10/0x10\n[   22.284001]  free_task+0xa2/0x160\n[   22.285699]  ? ftrace_stub_direct_tramp+0x10/0x10\n[   22.286752]  copy_process+0x2aae/0x7bc0\n\nInitialize the child function graph state immediately after\ndup_task_struct(), before the first fallible operation.","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97937","source_modified_at":"2026-10-19T09:11:03.903Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"6b1c66c9cca99bf00386481c7b2aa7394c26d8b8","lessThan":"1fadebbbf31f65beba353fa9d1373bf183e03fed","status":"affected","versionType":"git"},{"version":"6b1c66c9cca99bf00386481c7b2aa7394c26d8b8","lessThan":"08cacffeef8f64f1a222c93467ca84f24a46c953","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97937","source_modified_at":"2026-10-19T09:11:03.903Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"7.2","status":"affected"},{"version":"0","lessThan":"7.2","status":"unaffected","versionType":"semver"},{"version":"7.2.7","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97937","source_modified_at":"2026-10-19T09:11:03.903Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"1fadebbbf31f65beba353fa9d1373bf183e03fed","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97937","source_modified_at":"2026-10-19T09:11:03.903Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"08cacffeef8f64f1a222c93467ca84f24a46c953","basis":"first unaffected version stated in the CVE record"}],"cvss":7.8,"severity":"High","kev":{"listed":false},"epss":{"probability":0.00154,"percentile":0.04166,"score_date":"2026-10-23"},"published_at":"2026-09-25T10:22:51.075Z","modified_at":"2026-10-19T09:11:03.903Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-97937","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-19T09:11:03.903Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-97937","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/1fadebbbf31f65beba353fa9d1373bf183e03fed"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/08cacffeef8f64f1a222c93467ca84f24a46c953"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-19T09:11:03.903Z","content_hash":"13abd8c28702ee930cdcbba723b0408bef369b5d69e5ece61e33e213e0cccb4e"}}