{"id":"CVE-2026-97942","revision":"15c20588cb864d70bc1c4562766f1aa0","records":[{"revision":"15c20588cb864d70bc1c4562766f1aa0","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-97942","aliases":[],"title":"x86/alternatives: Exclude text poking against change_page_attr()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nx86/alternatives: Exclude text poking against change_page_attr()\n\nFrom time to time, the following BUG can be observed\nin the x86 alternatives patching code [0]:\n\n  > kernel BUG at arch/x86/kernel/alternative.c:2576!\n  > Oops: invalid opcode: 0000 [#1] SMP NOPTI\n  > CPU: 0 UID: 0 PID: 355 Comm: (udev-worker) Not tainted 7.1.3-1-default #1 PREEMPT(full) openSUSE Tumbleweed  8c1795b03ec64f997e57a8ad38b1161e3b98da64\n  > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS unknown 02/02/2022\n  > RIP: 0010:__text_poke+0x2aa/0x450\n  > Call Trace:\n  >  <TASK>\n  >  smp_text_poke_batch_finish+0x2a7/0x320\n  >  __static_call_transform+0xb7/0x220\n  >  arch_static_call_transform+0x5b/0xb0\n  >  __static_call_init+0xe9/0x270\n  >  static_call_module_notify+0x11f/0x150\n  >  notifier_call_chain+0x61/0xe0\n  >  blocking_notifier_call_chain_robust+0x63/0xc0\n  >  load_module+0x1c92/0x20c0\n  >  init_module_from_file+0xd8/0x140\n  >  idempotent_init_module+0x100/0x2f0\n  >  __x64_sys_finit_module+0x71/0xe0\n  >  do_syscall_64+0xe1/0x610\n  >  entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nwhich matches the following BUG_ON() in alternative.c:\n\n\t/*\n\t * If something went wrong, crash and burn since recovery paths are not\n\t * implemented.\n\t */\n\tBUG_ON(!pages[0] || (cross_page_boundary && !pages[1]));\n\nThis can happen if vmalloc_to_page() fails, for any reason. Such can happen\nif text poking races with CPA, which can possibly result in the collapsing\nof page tables (or breaking of PMD hugepages). It is not a problem for most\nusers of vmalloc_to_page() (they solely own the vmalloc'd range) but, when\nCONFIG_ARCH_HAS_EXECMEM_ROX=y, various modules own a single execmem vmalloc\nrange, and can call set_memory_*() in parallel on it. This can happen to\nrace against __text_poke and cause havoc in vmalloc_to_page().\n\nFix it by excluding against CPA using the init_mm mmap read lock.\n\n[ dhansen: Fix up SoB ordering. The actual code flow here was:\n\t   Pedro=>Lorenzo=>Mike=>Me which is reflected in the SoB chain\n\t   now. I *believe* Mike simply picked up Lorenzo's update to\n\t   Pedro's post from the Link ]","state":0,"publishedAt":"2026-09-25T10:22:54.188+00:00","modifiedAt":"2026-10-19T09:11:08.757+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"arch/x86/kernel/alternative.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"64f6a4e10c05ed527f0f24b7954964255e0d3535\",\n                            \"lessThan\": \"281e6f536f2f3f95d91938c5bd7ba9bcb4c1049d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"64f6a4e10c05ed527f0f24b7954964255e0d3535\",\n                            \"lessThan\": \"89c60435b90d32ab5e3a39da3ae73d463d07debe\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"64f6a4e10c05ed527f0f24b7954964255e0d3535\",\n                            \"lessThan\": \"1587d3394e254639cc36516256031334095e6ef3\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"arch/x86/kernel/alternative.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.15\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.15\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.53\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.7\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/281e6f536f2f3f95d91938c5bd7ba9bcb4c1049d","https://git.kernel.org/stable/c/89c60435b90d32ab5e3a39da3ae73d463d07debe","https://git.kernel.org/stable/c/1587d3394e254639cc36516256031334095e6ef3"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-97942","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-97942","identifiers":["CVE-2026-97942"]},"retained":false,"historicalAffected":[]}],"coverage":[]}