================================================================== BUG: KASAN: vmalloc-out-of-bounds in stack_map_get_build_id_offset+0x988/0x9b0 kernel/bpf/stackmap.c:147 Write of size 4 at addr ffffc9000c5b1ef0 by task syz.2.2466/10420 CPU: 1 PID: 10420 Comm: syz.2.2466 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106 print_address_description+0x71/0x200 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:420 kasan_report+0x122/0x150 mm/kasan/report.c:524 __asan_report_store4_noabort+0x17/0x20 mm/kasan/report_generic.c:355 stack_map_get_build_id_offset+0x988/0x9b0 kernel/bpf/stackmap.c:147 __bpf_get_stackid+0x5ac/0x960 kernel/bpf/stackmap.c:250 ____bpf_get_stackid_pe kernel/bpf/stackmap.c:365 [inline] bpf_get_stackid_pe+0x2ee/0x400 kernel/bpf/stackmap.c:334 bpf_prog_43b50326510579ba+0x21/0x36 bpf_dispatcher_nop_func include/linux/bpf.h:987 [inline] __bpf_prog_run include/linux/filter.h:607 [inline] bpf_prog_run include/linux/filter.h:614 [inline] bpf_overflow_handler+0x3c7/0x5e0 kernel/events/core.c:10273 __perf_event_overflow+0x458/0x640 kernel/events/core.c:9448 perf_swevent_overflow kernel/events/core.c:9531 [inline] perf_swevent_event+0x243/0x440 kernel/events/core.c:9582 do_perf_sw_event kernel/events/core.c:9695 [inline] ___perf_sw_event+0x3bf/0x500 kernel/events/core.c:9726 __perf_sw_event+0x134/0x270 kernel/events/core.c:9738 perf_sw_event include/linux/perf_event.h:1250 [inline] do_user_addr_fault+0xfe9/0x1030 arch/x86/mm/fault.c:1285 handle_page_fault arch/x86/mm/fault.c:1464 [inline] exc_page_fault+0x51/0xb0 arch/x86/mm/fault.c:1517 asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0010:do_strncpy_from_user lib/strncpy_from_user.c:41 [inline] RIP: 0010:strncpy_from_user+0xd7/0x2c0 lib/strncpy_from_user.c:139 Code: 89 f6 e8 cc 28 e1 fe 49 83 fe 07 0f 86 a5 00 00 00 4c 89 75 c8 49 c7 c6 f8 ff ff ff 45 31 ff 4c 89 65 c0 4c 89 6d d0 4d 89 fd <4b> 8b 1c 3c 48 b8 ff fe fe fe fe fe fe fe 4c 8d 3c 03 49 89 dc 49 RSP: 0018:ffffc9000c42fcb8 EFLAGS: 00050246 RAX: ffffffff82904e14 RBX: 0000000000000fe0 RCX: ffff88812afb5100 RDX: 0000000000000002 RSI: 0000000000000fe0 RDI: 0000000000000007 RBP: ffffc9000c42fd00 R08: ffffea0004717207 R09: 1ffffd40008e2e40 R10: dffffc0000000000 R11: fffff940008e2e41 R12: 0000000000000000 R13: 0000000000000000 R14: fffffffffffffff8 R15: 0000000000000000 getname_flags+0xf5/0x510 fs/namei.c:150 getname+0x19/0x20 fs/namei.c:218 do_sys_openat2+0xeb/0x820 fs/open.c:1337 do_sys_open fs/open.c:1359 [inline] __do_sys_openat fs/open.c:1375 [inline] __se_sys_openat fs/open.c:1370 [inline] __x64_sys_openat+0x136/0x160 fs/open.c:1370 x64_sys_call+0x783/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:258 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f9b41ba8f19 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9b42b47028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f9b41e25fa0 RCX: 00007f9b41ba8f19 RDX: 00000000000026e1 RSI: 0000000000000000 RDI: ffffffffffffff9c RBP: 00007f9b41c37f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9b41e26038 R14: 00007f9b41e25fa0 R15: 00007ffeee554558 The buggy address belongs to a 17-page vmalloc region starting at 0xffffc9000c5a1000 allocated at prealloc_elems_and_freelist+0x8a/0x1e0 kernel/bpf/stackmap.c:51 The buggy address belongs to the physical page: page:ffffea0004e312c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x138c4b flags: 0x4000000000000000(zone=1) raw: 4000000000000000 0000000000000000 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x506dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_ZERO|__GFP_ACCOUNT), pid 10420, tgid 10419 (syz.2.2466), ts 328412198921, free_ts 328350585250 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2673 prep_new_page+0x1c/0x110 mm/page_alloc.c:2680 get_page_from_freelist+0x2ca9/0x2d20 mm/page_alloc.c:4587 __alloc_pages+0x1fa/0x610 mm/page_alloc.c:5931 vm_area_alloc_pages mm/vmalloc.c:-1 [inline] __vmalloc_area_node mm/vmalloc.c:3084 [inline] __vmalloc_node_range+0x8ca/0x1440 mm/vmalloc.c:3256 __bpf_map_area_alloc kernel/bpf/syscall.c:334 [inline] bpf_map_area_alloc+0xd7/0xe0 kernel/bpf/syscall.c:341 prealloc_elems_and_freelist+0x8a/0x1e0 kernel/bpf/stackmap.c:51 stack_map_alloc+0x398/0x520 kernel/bpf/stackmap.c:117 find_and_alloc_map kernel/bpf/syscall.c:133 [inline] map_create+0x467/0xcf0 kernel/bpf/syscall.c:1126 __sys_bpf+0x34e/0x850 kernel/bpf/syscall.c:4988 __do_sys_bpf kernel/bpf/syscall.c:5110 [inline] __se_sys_bpf kernel/bpf/syscall.c:5108 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5108 x64_sys_call+0x488/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:322 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1581 [inline] free_pcp_prepare mm/page_alloc.c:1655 [inline] free_unref_page_prepare+0x81b/0x820 mm/page_alloc.c:3622 free_unref_page+0x93/0x530 mm/page_alloc.c:3720 free_the_page mm/page_alloc.c:863 [inline] __free_pages+0x67/0x100 mm/page_alloc.c:6021 free_pages+0x82/0x90 mm/page_alloc.c:6032 tlb_batch_list_free mm/mmu_gather.c:75 [inline] tlb_finish_mmu+0x2d1/0x380 mm/mmu_gather.c:364 exit_mmap+0x41d/0xc10 mm/mmap.c:3393 __mmput+0x92/0x340 kernel/fork.c:1321 mmput+0x4b/0x150 kernel/fork.c:1345 exit_mm kernel/exit.c:575 [inline] do_exit+0xa62/0x29f0 kernel/exit.c:883 do_group_exit+0x21b/0x2e0 kernel/exit.c:1040 get_signal+0x167c/0x1700 kernel/signal.c:2904 arch_do_signal_or_restart+0xd1/0x11c0 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x7a/0xb0 kernel/entry/common.c:174 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 Memory state around the buggy address: ffffc9000c5b1d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffc9000c5b1e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffffc9000c5b1e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f8 f8 ^ ffffc9000c5b1f00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc9000c5b1f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ================================================================== ---------------- Code disassembly (best guess): 0: 89 f6 mov %esi,%esi 2: e8 cc 28 e1 fe call 0xfee128d3 7: 49 83 fe 07 cmp $0x7,%r14 b: 0f 86 a5 00 00 00 jbe 0xb6 11: 4c 89 75 c8 mov %r14,-0x38(%rbp) 15: 49 c7 c6 f8 ff ff ff mov $0xfffffffffffffff8,%r14 1c: 45 31 ff xor %r15d,%r15d 1f: 4c 89 65 c0 mov %r12,-0x40(%rbp) 23: 4c 89 6d d0 mov %r13,-0x30(%rbp) 27: 4d 89 fd mov %r15,%r13 * 2a: 4b 8b 1c 3c mov (%r12,%r15,1),%rbx <-- trapping instruction 2e: 48 b8 ff fe fe fe fe movabs $0xfefefefefefefeff,%rax 35: fe fe fe 38: 4c 8d 3c 03 lea (%rbx,%rax,1),%r15 3c: 49 89 dc mov %rbx,%r12 3f: 49 rex.WB