================================================================== BUG: KASAN: slab-out-of-bounds in __bpf_get_stackid+0x6fa/0x960 kernel/bpf/stackmap.c:274 Write of size 64 at addr ffff888111d96890 by task syz.1.286/1529 CPU: 0 PID: 1529 Comm: syz.1.286 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 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_9f7ee0cc743aa62b+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+0x1ae/0x240 kernel/events/core.c:9531 perf_swevent_event+0x3a9/0x440 kernel/events/core.c:-1 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 0c 7c 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:ffffc90000fafb28 EFLAGS: 00050246 RAX: ffffffff828ff2d4 RBX: 000000000000007f RCX: ffff88811b1c9440 RDX: 0000000000000002 RSI: 000000000000007f RDI: 0000000000000007 RBP: ffffc90000fafb70 R08: ffff88811b1c9440 R09: 0000000000000002 R10: 0000000000000001 R11: 0000000000000002 R12: 0000000000000000 R13: 0000000000000000 R14: fffffffffffffff8 R15: 0000000000000000 strncpy_from_bpfptr include/linux/bpfptr.h:85 [inline] bpf_prog_load+0x1f1/0x1670 kernel/bpf/syscall.c:2508 __sys_bpf+0x57b/0x850 kernel/bpf/syscall.c:5006 __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 RIP: 0033:0x7fc78e59e159 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:00007fc78f4d7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fc78e825fa0 RCX: 00007fc78e59e159 RDX: 0000000000000094 RSI: 0000200000000a40 RDI: 0000000000000005 RBP: 00007fc78e63506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc78e826038 R14: 00007fc78e825fa0 R15: 00007fff99c28808 Allocated by task 1529: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_alloc_info+0x1f/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+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 The buggy address belongs to the object at ffff888111d96880 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 16 bytes inside of 64-byte region [ffff888111d96880, ffff888111d968c0) The buggy address belongs to the physical page: page:ffffea0004476580 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x111d96 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 ffffea0004cce3c0 dead000000000003 ffff888100042780 raw: 0000000000000000 0000000080200020 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 1252, tgid 1237 (syz.0.223), ts 58457482102, free_ts 55134266916 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 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1 allocate_slab mm/slub.c:1967 [inline] new_slab+0x98/0x3e0 mm/slub.c:2020 ___slab_alloc+0x70f/0xb70 mm/slub.c:3177 __slab_alloc+0x5e/0xa0 mm/slub.c:3263 slab_alloc_node mm/slub.c:3348 [inline] __kmem_cache_alloc_node+0x204/0x2d0 mm/slub.c:3423 __do_kmalloc_node mm/slab_common.c:937 [inline] __kmalloc_node_track_caller+0xa1/0x1e0 mm/slab_common.c:958 __do_krealloc mm/slab_common.c:1341 [inline] krealloc+0x6f/0x110 mm/slab_common.c:1374 copy_array kernel/bpf/verifier.c:955 [inline] copy_verifier_state+0xe9/0xb10 kernel/bpf/verifier.c:1139 push_stack+0x19b/0x4f0 kernel/bpf/verifier.c:1237 check_cond_jmp_op kernel/bpf/verifier.c:10492 [inline] do_check+0x96df/0xf140 kernel/bpf/verifier.c:12736 do_check_common+0x11c3/0x1970 kernel/bpf/verifier.c:14940 do_check_main kernel/bpf/verifier.c:15003 [inline] bpf_check+0xa04e/0x10e90 kernel/bpf/verifier.c:15580 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_slab+0xc7/0x1a0 mm/slub.c:2044 free_slab mm/slub.c:2059 [inline] discard_slab mm/slub.c:2065 [inline] __unfreeze_partials+0x15a/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_kmalloc mm/kasan/common.c:346 [inline] __kasan_krealloc+0x9a/0x140 mm/kasan/common.c:448 kasan_krealloc include/linux/kasan.h:232 [inline] __do_krealloc mm/slab_common.c:1337 [inline] krealloc+0xc7/0x110 mm/slab_common.c:1374 copy_array kernel/bpf/verifier.c:955 [inline] copy_verifier_state+0xe9/0xb10 kernel/bpf/verifier.c:1139 pop_stack kernel/bpf/verifier.c:1201 [inline] do_check+0x9383/0xf140 kernel/bpf/verifier.c:12725 do_check_common+0x11c3/0x1970 kernel/bpf/verifier.c:14940 do_check_main kernel/bpf/verifier.c:15003 [inline] bpf_check+0xa04e/0x10e90 kernel/bpf/verifier.c:15580 Memory state around the buggy address: ffff888111d96780: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888111d96800: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff888111d96880: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ^ ffff888111d96900: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888111d96980: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 89 f6 mov %esi,%esi 2: e8 0c 7c e1 fe call 0xfee17c13 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