================================================================== BUG: KASAN: slab-out-of-bounds in __bpf_get_stackid+0x6fa/0x960 kernel/bpf/stackmap.c:274 Write of size 56 at addr ffff8881211c5a10 by task syz.1.835/3379 CPU: 1 PID: 3379 Comm: syz.1.835 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x249/0x2a0 mm/kasan/generic.c:189 memcpy+0x44/0x70 mm/kasan/shadow.c:66 __bpf_get_stackid+0x6fa/0x960 kernel/bpf/stackmap.c:274 ____bpf_get_stackid_pe kernel/bpf/stackmap.c:365 [inline] bpf_get_stackid_pe+0x2ee/0x400 kernel/bpf/stackmap.c:334 bpf_prog_02c92f715e75ceb8+0x28/0x3d 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+0x3d0/0x5e0 kernel/events/core.c:10273 __perf_event_overflow+0x437/0x620 kernel/events/core.c:9448 perf_event_overflow kernel/events/core.c:9469 [inline] perf_swevent_hrtimer+0x400/0x5b0 kernel/events/core.c:10919 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x3bb/0x8e0 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3c7/0x8c0 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x11e/0x440 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:mutex_unlock+0x1/0x230 kernel/locking/mutex.c:558 Code: ff ff ff 66 0f 1f 44 00 00 55 48 89 e5 be 02 00 00 00 e8 c2 12 00 00 5d c3 90 90 90 90 90 90 90 90 90 90 90 b8 c9 ff ad 1b 55 <48> 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 83 ec 60 49 89 RSP: 0018:ffffc90010cd7bd0 EFLAGS: 00000282 RAX: ffffffff819a1b4f RBX: ffff88813296fc00 RCX: 0000000000080000 RDX: ffffc9000171a000 RSI: 000000000000002b RDI: ffff88813296fc10 RBP: ffffc90010cd7e80 R08: ffff88813b6a6f3f R09: 1ffff110276d4de7 R10: dffffc0000000000 R11: ffffed10276d4de8 R12: 0000000040042408 R13: dffffc0000000000 R14: fffff5200219af8c R15: 0000000000000000 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0x12f/0x1b0 fs/ioctl.c:856 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:856 x64_sys_call+0x58b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:17 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: 0033:0x7fd10319ce59 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:00007fd103f93028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fd103415fa0 RCX: 00007fd10319ce59 RDX: 0000000000000006 RSI: 0000000040042408 RDI: 0000000000000007 RBP: 00007fd103232d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd103416038 R14: 00007fd103415fa0 R15: 00007fffa3217958 Allocated by task 3379: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505 ____kasan_kmalloc mm/kasan/common.c:380 [inline] __kasan_kmalloc+0x95/0xb0 mm/kasan/common.c:389 kasan_kmalloc include/linux/kasan.h:212 [inline] __do_kmalloc_node mm/slab_common.c:938 [inline] __kmalloc_node+0xb2/0x1e0 mm/slab_common.c:945 kmalloc_node include/linux/slab.h:589 [inline] __bpf_map_area_alloc kernel/bpf/syscall.c:328 [inline] bpf_map_area_alloc+0x4b/0xe0 kernel/bpf/syscall.c:341 prealloc_elems_and_freelist+0x8a/0x1e0 kernel/bpf/stackmap.c:51 stack_map_alloc+0x3a7/0x530 kernel/bpf/stackmap.c:117 find_and_alloc_map kernel/bpf/syscall.c:133 [inline] map_create+0x49c/0xd80 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 The buggy address belongs to the object at ffff8881211c5a00 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 16 bytes inside of 64-byte region [ffff8881211c5a00, ffff8881211c5a40) The buggy address belongs to the physical page: page:ffffea0004847140 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1211c5 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 ffffea00042c9100 dead000000000005 ffff888100042780 raw: 0000000000000000 0000000000200020 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 2006, tgid 2005 (syz.0.450), ts 68131529850, free_ts 61175164360 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2672 prep_new_page+0x1c/0x110 mm/page_alloc.c:2679 get_page_from_freelist+0x2d12/0x2d80 mm/page_alloc.c:4585 __alloc_pages+0x1fa/0x610 mm/page_alloc.c:5929 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1 allocate_slab mm/slub.c:1967 [inline] new_slab+0x98/0x3d0 mm/slub.c:2020 ___slab_alloc+0x6bd/0xb20 mm/slub.c:3177 __slab_alloc+0x5e/0xa0 mm/slub.c:3263 slab_alloc_node mm/slub.c:3348 [inline] __kmem_cache_alloc_node+0x203/0x2c0 mm/slub.c:3423 __do_kmalloc_node mm/slab_common.c:937 [inline] __kmalloc_node_track_caller+0xa0/0x1e0 mm/slab_common.c:958 __do_krealloc mm/slab_common.c:1341 [inline] krealloc+0x6f/0x110 mm/slab_common.c:1374 push_jmp_history kernel/bpf/verifier.c:2462 [inline] is_state_visited kernel/bpf/verifier.c:12321 [inline] do_check+0x2d42/0xf070 kernel/bpf/verifier.c:12461 do_check_common+0x11ae/0x1950 kernel/bpf/verifier.c:14940 do_check_main kernel/bpf/verifier.c:15003 [inline] bpf_check+0x3f98/0x10d10 kernel/bpf/verifier.c:15580 bpf_prog_load+0x10f0/0x16a0 kernel/bpf/syscall.c:2624 __sys_bpf+0x57b/0x850 kernel/bpf/syscall.c:5006 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1580 [inline] free_pcp_prepare mm/page_alloc.c:1654 [inline] free_unref_page_prepare+0x7f8/0x800 mm/page_alloc.c:3620 free_unref_page+0x95/0x540 mm/page_alloc.c:3718 free_the_page mm/page_alloc.c:863 [inline] __free_pages+0x67/0x100 mm/page_alloc.c:6019 __free_slab+0xca/0x1a0 mm/slub.c:2044 free_slab mm/slub.c:2059 [inline] discard_slab mm/slub.c:2065 [inline] __unfreeze_partials+0x160/0x190 mm/slub.c:2614 put_cpu_partial+0xa9/0x100 mm/slub.c:2690 __slab_free+0x1c4/0x280 mm/slub.c:3589 do_slab_free mm/slub.c:3666 [inline] ___cache_free+0xbf/0xd0 mm/slub.c:3722 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0xc6/0x140 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x14a/0x170 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x24/0x80 mm/kasan/common.c:311 kasan_slab_alloc include/linux/kasan.h:202 [inline] slab_post_alloc_hook+0x4f/0x2d0 mm/slab.h:768 slab_alloc_node mm/slub.c:3382 [inline] __kmem_cache_alloc_node+0x192/0x2c0 mm/slub.c:3423 __do_kmalloc_node mm/slab_common.c:937 [inline] __kmalloc_node_track_caller+0xa0/0x1e0 mm/slab_common.c:958 kmalloc_reserve net/core/skbuff.c:449 [inline] __alloc_skb+0x236/0x4b0 net/core/skbuff.c:518 alloc_skb include/linux/skbuff.h:1322 [inline] alloc_uevent_skb+0x85/0x240 lib/kobject_uevent.c:290 Memory state around the buggy address: ffff8881211c5900: 00 00 00 00 00 00 00 03 fc fc fc fc fc fc fc fc ffff8881211c5980: 00 00 00 00 00 00 00 02 fc fc fc fc fc fc fc fc >ffff8881211c5a00: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ^ ffff8881211c5a80: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8881211c5b00: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess), 3 bytes skipped: 0: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 6: 55 push %rbp 7: 48 89 e5 mov %rsp,%rbp a: be 02 00 00 00 mov $0x2,%esi f: e8 c2 12 00 00 call 0x12d6 14: 5d pop %rbp 15: c3 ret 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 90 nop 1e: 90 nop 1f: 90 nop 20: 90 nop 21: b8 c9 ff ad 1b mov $0x1badffc9,%eax 26: 55 push %rbp * 27: 48 89 e5 mov %rsp,%rbp <-- trapping instruction 2a: 41 57 push %r15 2c: 41 56 push %r14 2e: 41 55 push %r13 30: 41 54 push %r12 32: 53 push %rbx 33: 48 83 e4 e0 and $0xffffffffffffffe0,%rsp 37: 48 83 ec 60 sub $0x60,%rsp 3b: 49 rex.WB 3c: 89 .byte 0x89