================================================================== BUG: KASAN: slab-out-of-bounds in __bpf_get_stackid+0x6cc/0xcf0 kernel/bpf/stackmap.c:265 Write of size 8 at addr ffff888030a9c258 by task syz.1.344/7002 CPU: 0 UID: 0 PID: 7002 Comm: syz.1.344 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 __bpf_get_stackid+0x6cc/0xcf0 kernel/bpf/stackmap.c:265 ____bpf_get_stackid_raw_tp kernel/trace/bpf_trace.c:1628 [inline] bpf_get_stackid_raw_tp+0x196/0x210 kernel/trace/bpf_trace.c:1617 bpf_prog_0269d7a1bf76b886+0x27/0x2f bpf_dispatcher_nop_func include/linux/bpf.h:1350 [inline] __bpf_prog_run include/linux/filter.h:721 [inline] bpf_prog_run include/linux/filter.h:728 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline] bpf_trace_run2+0x281/0x4b0 kernel/trace/bpf_trace.c:2116 __do_trace_kfree include/trace/events/kmem.h:97 [inline] trace_kfree include/trace/events/kmem.h:97 [inline] kfree+0x62f/0x6d0 mm/slub.c:6760 slab_free_after_rcu_debug+0x60/0x2a0 mm/slub.c:6611 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0xcab/0x1770 kernel/rcu/tree.c:2861 handle_softirqs+0x283/0x870 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__rcu_read_unlock+0x6f/0xe0 kernel/rcu/tree_plugin.h:445 Code: 48 c1 e8 03 42 0f b6 04 38 84 c0 75 66 41 83 3e 00 75 27 43 0f b6 04 3c 84 c0 75 41 8b 03 3d 00 00 00 40 73 0f 5b 41 5c 41 5d <41> 5e 41 5f c3 cc cc cc cc cc 90 0f 0b 90 eb eb e8 6c 00 00 00 eb RSP: 0018:ffffc900037ded48 EFLAGS: 00000287 RAX: 0000000000000000 RBX: ffffffff81a9711d RCX: 122dfede6da48d00 RDX: 0000000000000000 RSI: ffffffff8d6f525f RDI: ffff8880250c3c80 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81a9711d R10: ffffc900037dee38 R11: ffffffff81aaf950 R12: ffff8880250c3c80 R13: 0000000000000060 R14: ffff8880250c4108 R15: dffffc0000000000 rcu_read_unlock include/linux/rcupdate.h:873 [inline] class_rcu_destructor include/linux/rcupdate.h:1169 [inline] is_module_text_address+0x190/0x1e0 kernel/module/main.c:3847 kernel_text_address+0x94/0xe0 kernel/extable.c:119 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xfc/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __kmalloc_cache_node_noprof+0x471/0x6f0 mm/slub.c:5736 kmalloc_node_noprof include/linux/slab.h:983 [inline] __get_vm_area_node+0x13f/0x300 mm/vmalloc.c:3182 __vmalloc_node_range_noprof+0x30c/0x12d0 mm/vmalloc.c:3857 __vmalloc_node_noprof mm/vmalloc.c:3960 [inline] vmalloc_noprof+0xb2/0xf0 mm/vmalloc.c:3993 bpf_prog_calc_tag+0x4c/0x370 kernel/bpf/core.c:304 resolve_pseudo_ldimm64+0xbc/0xc50 kernel/bpf/verifier.c:20525 bpf_check+0x1c4a/0x1d720 kernel/bpf/verifier.c:24609 bpf_prog_load+0x13ba/0x19e0 kernel/bpf/syscall.c:3062 __sys_bpf+0x507/0x860 kernel/bpf/syscall.c:6134 __do_sys_bpf kernel/bpf/syscall.c:6244 [inline] __se_sys_bpf kernel/bpf/syscall.c:6242 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6242 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8cadb8eec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8caeb14038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f8cadde5fa0 RCX: 00007f8cadb8eec9 RDX: 0000000000000048 RSI: 00002000000017c0 RDI: 0000000000000005 RBP: 00007f8cadc11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8cadde6038 R14: 00007f8cadde5fa0 R15: 00007ffd15dea298 Allocated by task 7002: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5603 [inline] __kmalloc_node_noprof+0x56d/0x800 mm/slub.c:5609 kmalloc_node_noprof include/linux/slab.h:987 [inline] __bpf_map_area_alloc kernel/bpf/syscall.c:395 [inline] bpf_map_area_alloc+0x64/0x180 kernel/bpf/syscall.c:408 prealloc_elems_and_freelist+0x86/0x1d0 kernel/bpf/stackmap.c:51 stack_map_alloc+0x33f/0x4c0 kernel/bpf/stackmap.c:114 map_create+0xaa3/0x1640 kernel/bpf/syscall.c:1497 __sys_bpf+0x5f0/0x860 kernel/bpf/syscall.c:6116 __do_sys_bpf kernel/bpf/syscall.c:6244 [inline] __se_sys_bpf kernel/bpf/syscall.c:6242 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6242 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888030a9c000 which belongs to the cache kmalloc-cg-1k of size 1024 The buggy address is located 24 bytes to the right of allocated 576-byte region [ffff888030a9c000, ffff888030a9c240) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x30a98 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888031d34401 ksm flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813fe30280 ffffea0000cae400 dead000000000003 raw: 0000000000000000 0000000080100010 00000000f5000000 ffff888031d34401 head: 00fff00000000040 ffff88813fe30280 ffffea0000cae400 dead000000000003 head: 0000000000000000 0000000080100010 00000000f5000000 ffff888031d34401 head: 00fff00000000003 ffffea0000c2a601 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 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 5503, tgid 5503 (dhcpcd), ts 73782229502, free_ts 73781754991 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3884 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3030 [inline] allocate_slab+0x96/0x3a0 mm/slub.c:3203 new_slab mm/slub.c:3257 [inline] ___slab_alloc+0xe94/0x1920 mm/slub.c:4627 __slab_alloc+0x65/0x100 mm/slub.c:4746 __slab_alloc_node mm/slub.c:4822 [inline] slab_alloc_node mm/slub.c:5233 [inline] __do_kmalloc_node mm/slub.c:5602 [inline] __kmalloc_node_track_caller_noprof+0x5c7/0x800 mm/slub.c:5712 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:601 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0xca/0x890 net/core/skbuff.c:6671 sock_alloc_send_pskb+0x84d/0x980 net/core/sock.c:2965 unix_stream_sendmsg+0x4bd/0xdf0 net/unix/af_unix.c:-1 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 sock_write_iter+0x279/0x360 net/socket.c:1195 do_iter_readv_writev+0x620/0x8c0 fs/read_write.c:-1 page last free pid 5503 tgid 5503 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2906 free_large_kmalloc+0x13a/0x1f0 mm/slub.c:6699 skb_release_data+0x62d/0x7c0 net/core/skbuff.c:1087 skb_release_all net/core/skbuff.c:1152 [inline] __kfree_skb net/core/skbuff.c:1166 [inline] consume_skb+0x9e/0xf0 net/core/skbuff.c:1398 netlink_recvmsg+0x5b2/0xa30 net/netlink/af_netlink.c:1974 sock_recvmsg_nosec net/socket.c:1078 [inline] sock_recvmsg+0x22c/0x270 net/socket.c:1100 ____sys_recvmsg+0x1c9/0x460 net/socket.c:2850 ___sys_recvmsg+0x1b5/0x510 net/socket.c:2892 __sys_recvmsg net/socket.c:2925 [inline] __do_sys_recvmsg net/socket.c:2931 [inline] __se_sys_recvmsg net/socket.c:2928 [inline] __x64_sys_recvmsg+0x198/0x260 net/socket.c:2928 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888030a9c100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888030a9c180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888030a9c200: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ^ ffff888030a9c280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888030a9c300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 48 c1 e8 03 shr $0x3,%rax 4: 42 0f b6 04 38 movzbl (%rax,%r15,1),%eax 9: 84 c0 test %al,%al b: 75 66 jne 0x73 d: 41 83 3e 00 cmpl $0x0,(%r14) 11: 75 27 jne 0x3a 13: 43 0f b6 04 3c movzbl (%r12,%r15,1),%eax 18: 84 c0 test %al,%al 1a: 75 41 jne 0x5d 1c: 8b 03 mov (%rbx),%eax 1e: 3d 00 00 00 40 cmp $0x40000000,%eax 23: 73 0f jae 0x34 25: 5b pop %rbx 26: 41 5c pop %r12 28: 41 5d pop %r13 * 2a: 41 5e pop %r14 <-- trapping instruction 2c: 41 5f pop %r15 2e: c3 ret 2f: cc int3 30: cc int3 31: cc int3 32: cc int3 33: cc int3 34: 90 nop 35: 0f 0b ud2 37: 90 nop 38: eb eb jmp 0x25 3a: e8 6c 00 00 00 call 0xab 3f: eb .byte 0xeb