================================================================== BUG: KASAN: slab-out-of-bounds in __bpf_get_stackid+0x6fa/0x960 kernel/bpf/stackmap.c:274 Write of size 64 at addr ffff88811008c410 by task syz.4.232/1302 CPU: 1 PID: 1302 Comm: syz.4.232 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026 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_47bcecfbcadd1995+0x21/0x39 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 ac 2e 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:ffffc9000f8dfb28 EFLAGS: 00050246 RAX: ffffffff82904834 RBX: 000000000000007f RCX: ffff88812071d100 RDX: 0000000000000000 RSI: 000000000000007f RDI: 0000000000000007 RBP: ffffc9000f8dfb70 R08: ffff88812071d100 R09: 0000000000000002 R10: 0000000000000001 R11: 0000000000000000 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: 0033:0x7f74d439f559 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:00007f74d52fb028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f74d4625fa0 RCX: 00007f74d439f559 RDX: 0000000000000090 RSI: 00002000000023c0 RDI: 0000000000000005 RBP: 00007f74d4436b50 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f74d4626038 R14: 00007f74d4625fa0 R15: 00007ffd12b27db8 Allocated by task 1302: 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 ffff88811008c400 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 16 bytes inside of 64-byte region [ffff88811008c400, ffff88811008c440) The buggy address belongs to the physical page: page:ffffea0004402300 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11008c flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 0000000000000000 dead000000000122 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 1306, tgid 1306 (syz-executor), ts 44951541736, free_ts 44905740649 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+0xa2/0x1e0 mm/slab_common.c:945 kmalloc_node include/linux/slab.h:589 [inline] kvmalloc_node+0x28a/0x460 mm/util.c:592 kvmalloc include/linux/slab.h:716 [inline] simple_xattr_alloc+0x43/0xa0 fs/xattr.c:1008 shmem_initxattrs+0x8d/0x1e0 mm/shmem.c:3294 security_inode_init_security+0x295/0x3c0 security/security.c:1134 shmem_symlink+0xd0/0x4c0 mm/shmem.c:3166 vfs_symlink+0x261/0x3f0 fs/namei.c:4478 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_list+0x117/0x8d0 mm/page_alloc.c:3773 release_pages+0xc7e/0xce0 mm/swap.c:1053 free_pages_and_swap_cache+0x86/0xa0 mm/swap_state.c:316 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline] tlb_flush_mmu_free mm/mmu_gather.c:254 [inline] tlb_flush_mmu mm/mmu_gather.c:261 [inline] tlb_finish_mmu+0x1b2/0x380 mm/mmu_gather.c:361 exit_mmap+0x41d/0xc10 mm/mmap.c:3384 __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: ffff88811008c300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88811008c380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88811008c400: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ^ ffff88811008c480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88811008c500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 89 f6 mov %esi,%esi 2: e8 ac 2e e1 fe call 0xfee12eb3 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