================================================================== BUG: KASAN: slab-out-of-bounds in __bpf_get_stackid+0x6bf/0x900 kernel/bpf/stackmap.c:271 Write of size 56 at addr ffff88805e9bcd10 by task syz.0.1936/12206 CPU: 0 PID: 12206 Comm: syz.0.1936 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xa8/0x210 mm/kasan/report.c:468 kasan_report+0x117/0x150 mm/kasan/report.c:581 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x241/0x290 mm/kasan/generic.c:187 __asan_memcpy+0x40/0x70 mm/kasan/shadow.c:106 __bpf_get_stackid+0x6bf/0x900 kernel/bpf/stackmap.c:271 ____bpf_get_stackid_pe kernel/bpf/stackmap.c:362 [inline] bpf_get_stackid_pe+0x343/0x410 kernel/bpf/stackmap.c:331 bpf_prog_02c92f715e75ceb8+0x30/0x45 bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline] __bpf_prog_run include/linux/filter.h:616 [inline] bpf_prog_run include/linux/filter.h:623 [inline] bpf_overflow_handler+0x1fc/0x510 kernel/events/core.c:10584 __perf_event_overflow+0x447/0x630 kernel/events/core.c:9720 perf_swevent_overflow+0x268/0x340 kernel/events/core.c:9803 perf_swevent_event+0x45c/0x570 kernel/events/core.c:-1 do_perf_sw_event kernel/events/core.c:9967 [inline] ___perf_sw_event+0x4a7/0x730 kernel/events/core.c:9998 __perf_sw_event+0x139/0x270 kernel/events/core.c:10010 perf_sw_event include/linux/perf_event.h:1442 [inline] do_user_addr_fault+0x123e/0x12c0 arch/x86/mm/fault.c:1278 handle_page_fault arch/x86/mm/fault.c:1463 [inline] exc_page_fault+0x64/0x100 arch/x86/mm/fault.c:1516 asm_exc_page_fault+0x26/0x30 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+0xff/0x2d0 lib/strncpy_from_user.c:139 Code: 4c 89 ee e8 63 69 2a fd 49 83 fd 07 0f 86 a1 00 00 00 4c 89 74 24 08 48 c7 44 24 10 f8 ff ff ff 45 31 e4 4c 89 3c 24 49 89 de <4f> 8b 3c 27 48 b8 ff fe fe fe fe fe fe fe 49 8d 1c 07 4c 89 fd 48 RSP: 0018:ffffc900192dfb50 EFLAGS: 00050246 RAX: ffffffff845cbcad RBX: ffffc900192dfc70 RCX: ffff88802452da00 RDX: 0000000000000000 RSI: 000000000000007f RDI: 0000000000000007 RBP: ffffc900192dfd70 R08: ffff88802452da00 R09: 0000000000000003 R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000 R13: 000000000000007f R14: ffffc900192dfc70 R15: 0000000000000000 bpf_prog_load+0xcea/0x1670 kernel/bpf/syscall.c:2714 __sys_bpf+0x5ba/0x890 kernel/bpf/syscall.c:5477 __do_sys_bpf kernel/bpf/syscall.c:5581 [inline] __se_sys_bpf kernel/bpf/syscall.c:5579 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5579 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f8b7599c819 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:00007f8b767da028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f8b75c15fa0 RCX: 00007f8b7599c819 RDX: 0000000000000094 RSI: 0000200000000800 RDI: 0000000000000005 RBP: 00007f8b75a32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8b75c16038 R14: 00007f8b75c15fa0 R15: 00007ffdd3bb2168 Allocated by task 12207: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:198 [inline] __do_kmalloc_node mm/slab_common.c:1007 [inline] __kmalloc_node+0xb4/0x230 mm/slab_common.c:1014 kmalloc_node include/linux/slab.h:620 [inline] __bpf_map_area_alloc kernel/bpf/syscall.c:303 [inline] bpf_map_area_alloc+0x5e/0x110 kernel/bpf/syscall.c:316 prealloc_elems_and_freelist+0x86/0x1c0 kernel/bpf/stackmap.c:51 stack_map_alloc+0x33a/0x4c0 kernel/bpf/stackmap.c:114 map_create+0x877/0x12f0 kernel/bpf/syscall.c:1247 __sys_bpf+0x651/0x890 kernel/bpf/syscall.c:5459 __do_sys_bpf kernel/bpf/syscall.c:5581 [inline] __se_sys_bpf kernel/bpf/syscall.c:5579 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5579 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88805e9bcd00 which belongs to the cache kmalloc-cg-64 of size 64 The buggy address is located 16 bytes inside of allocated 40-byte region [ffff88805e9bcd00, ffff88805e9bcd28) The buggy address belongs to the physical page: page:ffffea00017a6f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5e9bc memcg:ffff88802e356c01 ksm flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000800 ffff888017c4da00 ffffea00012a2a00 0000000000000003 raw: 0000000000000000 0000000080200020 00000001ffffffff ffff88802e356c01 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 5769, tgid 5769 (syz-executor), ts 350528899279, free_ts 350528279918 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1581 prep_new_page mm/page_alloc.c:1588 [inline] get_page_from_freelist+0x1951/0x19e0 mm/page_alloc.c:3220 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4500 alloc_slab_page+0x5d/0x160 mm/slub.c:1881 allocate_slab mm/slub.c:2028 [inline] new_slab+0x87/0x2d0 mm/slub.c:2081 ___slab_alloc+0xc5d/0x12f0 mm/slub.c:3253 __slab_alloc mm/slub.c:3339 [inline] __slab_alloc_node mm/slub.c:3392 [inline] slab_alloc_node mm/slub.c:3485 [inline] __kmem_cache_alloc_node+0x19e/0x250 mm/slub.c:3534 kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1098 kmalloc include/linux/slab.h:600 [inline] alloc_fdtable+0xca/0x2c0 fs/file.c:147 dup_fd+0x786/0xa50 fs/file.c:346 copy_files+0xc3/0x120 kernel/fork.c:1794 copy_process+0x15ab/0x3d80 kernel/fork.c:2494 kernel_clone+0x24b/0x8a0 kernel/fork.c:2914 __do_sys_clone kernel/fork.c:3057 [inline] __se_sys_clone kernel/fork.c:3041 [inline] __x64_sys_clone+0x1b7/0x230 kernel/fork.c:3041 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 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:24 [inline] free_pages_prepare mm/page_alloc.c:1181 [inline] free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2365 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2458 discard_slab mm/slub.c:2127 [inline] __unfreeze_partials+0x1cf/0x210 mm/slub.c:2667 put_cpu_partial+0x17c/0x250 mm/slub.c:2743 __slab_free+0x319/0x400 mm/slub.c:3700 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] kmem_cache_alloc_node+0x14c/0x320 mm/slub.c:3540 alloc_task_struct_node kernel/fork.c:174 [inline] dup_task_struct+0x57/0x7c0 kernel/fork.c:1116 copy_process+0x586/0x3d80 kernel/fork.c:2331 kernel_clone+0x24b/0x8a0 kernel/fork.c:2914 __do_sys_clone kernel/fork.c:3057 [inline] __se_sys_clone kernel/fork.c:3041 [inline] __x64_sys_clone+0x1b7/0x230 kernel/fork.c:3041 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Memory state around the buggy address: ffff88805e9bcc00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88805e9bcc80: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc >ffff88805e9bcd00: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ^ ffff88805e9bcd80: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc ffff88805e9bce00: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 4c 89 ee mov %r13,%rsi 3: e8 63 69 2a fd call 0xfd2a696b 8: 49 83 fd 07 cmp $0x7,%r13 c: 0f 86 a1 00 00 00 jbe 0xb3 12: 4c 89 74 24 08 mov %r14,0x8(%rsp) 17: 48 c7 44 24 10 f8 ff movq $0xfffffffffffffff8,0x10(%rsp) 1e: ff ff 20: 45 31 e4 xor %r12d,%r12d 23: 4c 89 3c 24 mov %r15,(%rsp) 27: 49 89 de mov %rbx,%r14 * 2a: 4f 8b 3c 27 mov (%r15,%r12,1),%r15 <-- trapping instruction 2e: 48 b8 ff fe fe fe fe movabs $0xfefefefefefefeff,%rax 35: fe fe fe 38: 49 8d 1c 07 lea (%r15,%rax,1),%rbx 3c: 4c 89 fd mov %r15,%rbp 3f: 48 rex.W