================================================================== BUG: KASAN: slab-out-of-bounds in stack_map_get_build_id_offset+0x833/0x9b0 kernel/bpf/stackmap.c:147 Write of size 4 at addr ffff88811b591b30 by task syz.3.325/1706 CPU: 0 PID: 1706 Comm: syz.3.325 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 __asan_report_store4_noabort+0x17/0x20 mm/kasan/report_generic.c:355 stack_map_get_build_id_offset+0x833/0x9b0 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_2414a5d5030ea31b+0x21/0x25 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:fault_in_readable+0xd5/0x150 mm/gup.c:1915 Code: f1 49 c7 ff 4d 89 f4 49 81 cc ff 0f 00 00 4d 89 f7 49 01 dc 49 81 e4 00 f0 ff ff 4d 39 e6 77 3d e8 d0 49 c7 ff 4d 39 e7 74 40 <41> 8a 07 88 45 df 49 81 c7 00 10 00 00 4d 39 e7 74 07 e8 b4 49 c7 RSP: 0018:ffffc90000dd7a28 EFLAGS: 00050287 RAX: ffffffff81aa1fd0 RBX: 0000000000001000 RCX: 0000000000080000 RDX: ffffc90002aef000 RSI: 00000000000002f7 RDI: 00000000000002f8 RBP: ffffc90000dd7a50 R08: ffff888131d05100 R09: 0000000000000002 R10: 0000000000000006 R11: 0000000000000002 R12: 0000200000004000 R13: dffffc0000000000 R14: 0000200000002180 R15: 0000200000003000 fault_in_iov_iter_readable+0xc3/0x310 lib/iov_iter.c:356 generic_perform_write+0x212/0x740 mm/filemap.c:3905 __generic_file_write_iter+0x17a/0x230 mm/filemap.c:4014 generic_file_write_iter+0xae/0x310 mm/filemap.c:4043 call_write_iter include/linux/fs.h:2282 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x5ef/0xd00 fs/read_write.c:584 ksys_write+0x14a/0x260 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x7b/0x90 fs/read_write.c:646 x64_sys_call+0x27b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:2 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: 0033:0x7f150ab9e159 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:00007f150bae1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f150ae25fa0 RCX: 00007f150ab9e159 RDX: 0000000013bb711e RSI: 0000200000000180 RDI: 000000000000000c RBP: 00007f150ac3503b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f150ae26038 R14: 00007f150ae25fa0 R15: 00007fff99993818 Allocated by task 1706: 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 ffff88811b591800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 816 bytes inside of 1024-byte region [ffff88811b591800, ffff88811b591c00) The buggy address belongs to the physical page: page:ffffea00046d6400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11b590 head:ffffea00046d6400 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 0000000000000000 dead000000000001 ffff888100043080 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 103, tgid 103 (udevd), ts 7473566942, free_ts 0 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 kmalloc_reserve net/core/skbuff.c:449 [inline] __alloc_skb+0x226/0x4a0 net/core/skbuff.c:518 alloc_skb include/linux/skbuff.h:1322 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1183 [inline] netlink_sendmsg+0x635/0xbd0 net/netlink/af_netlink.c:1853 sock_sendmsg_nosec net/socket.c:716 [inline] __sock_sendmsg net/socket.c:728 [inline] ____sys_sendmsg+0x5fb/0x9c0 net/socket.c:2509 ___sys_sendmsg+0x2a2/0x360 net/socket.c:2563 __sys_sendmsg net/socket.c:2592 [inline] __do_sys_sendmsg net/socket.c:2601 [inline] __se_sys_sendmsg net/socket.c:2599 [inline] __x64_sys_sendmsg+0x20d/0x2e0 net/socket.c:2599 x64_sys_call+0x171/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:47 page_owner free stack trace missing Memory state around the buggy address: ffff88811b591a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88811b591a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88811b591b00: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc ^ ffff88811b591b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88811b591c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: f1 int1 1: 49 c7 rex.WB (bad) 3: ff 4d 89 decl -0x77(%rbp) 6: f4 hlt 7: 49 81 cc ff 0f 00 00 or $0xfff,%r12 e: 4d 89 f7 mov %r14,%r15 11: 49 01 dc add %rbx,%r12 14: 49 81 e4 00 f0 ff ff and $0xfffffffffffff000,%r12 1b: 4d 39 e6 cmp %r12,%r14 1e: 77 3d ja 0x5d 20: e8 d0 49 c7 ff call 0xffc749f5 25: 4d 39 e7 cmp %r12,%r15 28: 74 40 je 0x6a * 2a: 41 8a 07 mov (%r15),%al <-- trapping instruction 2d: 88 45 df mov %al,-0x21(%rbp) 30: 49 81 c7 00 10 00 00 add $0x1000,%r15 37: 4d 39 e7 cmp %r12,%r15 3a: 74 07 je 0x43 3c: e8 .byte 0xe8 3d: b4 49 mov $0x49,%ah 3f: c7 .byte 0xc7