{ "schema_version": "1.6.1", "id": "RPI-CVE-2025-21866", "modified": "2026-10-07T17:22:01Z", "upstream": [ "CVE-2025-21866" ], "published": "2025-03-12T09:43:14Z", "summary": "powerpc/code-patching: Fix KASAN hit by not flagging text patching area as VM_ALLOC", "details": "In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/code-patching: Fix KASAN hit by not flagging text patching area as VM_ALLOC\n\nErhard reported the following KASAN hit while booting his PowerMac G4\nwith a KASAN-enabled kernel 6.13-rc6:\n\n BUG: KASAN: vmalloc-out-of-bounds in copy_to_kernel_nofault+0xd8/0x1c8\n Write of size 8 at addr f1000000 by task chronyd/1293\n\n CPU: 0 UID: 123 PID: 1293 Comm: chronyd Tainted: G W 6.13.0-rc6-PMacG4 #2\n Tainted: [W]=WARN\n Hardware name: PowerMac3,6 7455 0x80010303 PowerMac\n Call Trace:\n [c2437590] [c1631a84] dump_stack_lvl+0x70/0x8c (unreliable)\n [c24375b0] [c0504998] print_report+0xdc/0x504\n [c2437610] [c050475c] kasan_report+0xf8/0x108\n [c2437690] [c0505a3c] kasan_check_range+0x24/0x18c\n [c24376a0] [c03fb5e4] copy_to_kernel_nofault+0xd8/0x1c8\n [c24376c0] [c004c014] patch_instructions+0x15c/0x16c\n [c2437710] [c00731a8] bpf_arch_text_copy+0x60/0x7c\n [c2437730] [c0281168] bpf_jit_binary_pack_finalize+0x50/0xac\n [c2437750] [c0073cf4] bpf_int_jit_compile+0xb30/0xdec\n [c2437880] [c0280394] bpf_prog_select_runtime+0x15c/0x478\n [c24378d0] [c1263428] bpf_prepare_filter+0xbf8/0xc14\n [c2437990] [c12677ec] bpf_prog_create_from_user+0x258/0x2b4\n [c24379d0] [c027111c] do_seccomp+0x3dc/0x1890\n [c2437ac0] [c001d8e0] system_call_exception+0x2dc/0x420\n [c2437f30] [c00281ac] ret_from_syscall+0x0/0x2c\n --- interrupt: c00 at 0x5a1274\n NIP: 005a1274 LR: 006a3b3c CTR: 005296c8\n REGS: c2437f40 TRAP: 0c00 Tainted: G W (6.13.0-rc6-PMacG4)\n MSR: 0200f932 CR: 24004422 XER: 00000000\n\n GPR00: 00000166 af8f3fa0 a7ee3540 00000001 00000000 013b6500 005a5858 0200f932\n GPR08: 00000000 00001fe9 013d5fc8 005296c8 2822244c 00b2fcd8 00000000 af8f4b57\n GPR16: 00000000 00000001 00000000 00000000 00000000 00000001 00000000 00000002\n GPR24: 00afdbb0 00000000 00000000 00000000 006e0004 013ce060 006e7c1c 00000001\n NIP [005a1274] 0x5a1274\n LR [006a3b3c] 0x6a3b3c\n --- interrupt: c00\n\n The buggy address belongs to the virtual mapping at\n [f1000000, f1002000) created by:\n text_area_cpu_up+0x20/0x190\n\n The buggy address belongs to the physical page:\n page: refcount:1 mapcount:0 mapping:00000000 index:0x0 pfn:0x76e30\n flags: 0x80000000(zone=2)\n raw: 80000000 00000000 00000122 00000000 00000000 00000000 ffffffff 00000001\n raw: 00000000\n page dumped because: kasan: bad access detected\n\n Memory state around the buggy address:\n f0ffff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n f0ffff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n >f1000000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8\n ^\n f1000080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8\n f1000100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8\n ==================================================================\n\nf8 corresponds to KASAN_VMALLOC_INVALID which means the area is not\ninitialised hence not supposed to be used yet.\n\nPowerpc text patching infrastructure allocates a virtual memory area\nusing get_vm_area() and flags it as VM_ALLOC. But that flag is meant\nto be used for vmalloc() and vmalloc() allocated memory is not\nsupposed to be used before a call to __vmalloc_node_range() which is\nnever called for that area.\n\nThat went undetected until commit e4137f08816b (\"mm, kasan, kmsan:\ninstrument copy_from/to_kernel_nofault\")\n\nThe area allocated by text_area_cpu_up() is not vmalloc memory, it is\nmapped directly on demand when needed by map_kernel_page(). There is\nno VM flag corresponding to such usage, so just pass no flag. That way\nthe area will be unpoisonned and usable immediately.", "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:12", "name": "linux" }, "versions": [ "1:6.1.47-1+rpt4" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.1.0-rpi3-rpi-2712", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v6", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v8", "binary_version": "1:6.1.47-1+rpt4" } ] }, "database_specific": { "per_version": { "1:6.1.47-1+rpt4": { "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e", "upstream_version": "6.1.47", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.130", "compiled_filter": false } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2025-21866" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/97de5852058a299ba447cd9782fe96488d30108b" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/f8d4c5b653c1bc0df56e15658bbf64fc359adc4e" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/6847b3e40bb963e57b61d1cc6fe84cb37b9d3d4c" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/c905a3053518212a1017e50bd2be3bee59305bb0" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/2d542f13d26344e3452eee77613026ce9b653065" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/8d06e9208184b2851fa79a3a39d6860320c8bdf8" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/2e6c80423f201405fd65254e52decd21663896f3" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/d262a192d38e527faa5984629aabda2e0d1c4f54" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-05-12T04:54:46Z" } }