================================================================== BUG: KASAN: use-after-free in dev_map_enqueue+0x40/0x340 kernel/bpf/devmap.c:532 Read of size 8 at addr ffff888131e9ab00 by task syz.2.1637/6403 CPU: 0 PID: 6403 Comm: syz.2.1637 Not tainted 6.1.129-syzkaller-00051-gc1fd50266bd6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0x158/0x4e0 mm/kasan/report.c:427 kasan_report+0x13c/0x170 mm/kasan/report.c:531 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:351 dev_map_enqueue+0x40/0x340 kernel/bpf/devmap.c:532 __xdp_do_redirect_frame net/core/filter.c:4319 [inline] xdp_do_redirect_frame+0x2b5/0x800 net/core/filter.c:4381 xdp_test_run_batch net/bpf/test_run.c:314 [inline] bpf_test_run_xdp_live+0xc30/0x1f70 net/bpf/test_run.c:362 bpf_prog_test_run_xdp+0x7d1/0x1130 net/bpf/test_run.c:1393 bpf_prog_test_run+0x3b0/0x630 kernel/bpf/syscall.c:3670 __sys_bpf+0x59f/0x7f0 kernel/bpf/syscall.c:5025 __do_sys_bpf kernel/bpf/syscall.c:5111 [inline] __se_sys_bpf kernel/bpf/syscall.c:5109 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5109 x64_sys_call+0x87f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:322 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fcdae58d169 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:00007fcdae3de038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fcdae7a6080 RCX: 00007fcdae58d169 RDX: 0000000000000050 RSI: 00002000000000c0 RDI: 000000000000000a RBP: 00007fcdae60e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fcdae7a6080 R15: 00007ffc74d143a8 Allocated by task 6360: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505 ____kasan_kmalloc mm/kasan/common.c:379 [inline] __kasan_kmalloc+0x9c/0xb0 mm/kasan/common.c:388 kasan_kmalloc include/linux/kasan.h:212 [inline] __do_kmalloc_node mm/slab_common.c:938 [inline] __kmalloc_node+0xb4/0x1e0 mm/slab_common.c:945 kmalloc_node include/linux/slab.h:589 [inline] bpf_map_kmalloc_node+0xd0/0x2c0 kernel/bpf/syscall.c:454 __dev_map_alloc_node+0x5c/0x4e0 kernel/bpf/devmap.c:851 __dev_map_update_elem kernel/bpf/devmap.c:916 [inline] dev_map_update_elem+0x20e/0x3f0 kernel/bpf/devmap.c:935 bpf_map_update_value+0x23a/0x410 kernel/bpf/syscall.c:228 map_update_elem+0x500/0x680 kernel/bpf/syscall.c:1443 __sys_bpf+0x460/0x7f0 kernel/bpf/syscall.c:4995 __do_sys_bpf kernel/bpf/syscall.c:5111 [inline] __se_sys_bpf kernel/bpf/syscall.c:5109 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5109 x64_sys_call+0x87f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:322 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 339: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x131/0x180 mm/kasan/common.c:241 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:249 kasan_slab_free include/linux/kasan.h:178 [inline] slab_free_hook mm/slub.c:1745 [inline] slab_free_freelist_hook mm/slub.c:1771 [inline] slab_free mm/slub.c:3686 [inline] __kmem_cache_free+0x21d/0x410 mm/slub.c:3702 kfree+0x7a/0xf0 mm/slab_common.c:990 dev_map_free+0x593/0x6c0 kernel/bpf/devmap.c:238 bpf_map_free_deferred+0xf7/0x1b0 kernel/bpf/syscall.c:637 process_one_work+0x73d/0xcb0 kernel/workqueue.c:2299 worker_thread+0xa60/0x1260 kernel/workqueue.c:2446 kthread+0x26d/0x300 kernel/kthread.c:386 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb4/0xc0 mm/kasan/generic.c:486 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496 insert_work+0x56/0x310 kernel/workqueue.c:1368 __queue_work+0x9b6/0xd70 kernel/workqueue.c:1527 queue_work_on+0x105/0x170 kernel/workqueue.c:1555 queue_work include/linux/workqueue.h:510 [inline] schedule_work include/linux/workqueue.h:571 [inline] nf_nat_masq_schedule+0x4bc/0x600 net/netfilter/nf_nat_masquerade.c:130 masq_inet6_event+0x124/0x180 net/netfilter/nf_nat_masquerade.c:295 notifier_call_chain kernel/notifier.c:87 [inline] atomic_notifier_call_chain+0x95/0x100 kernel/notifier.c:225 inet6addr_notifier_call_chain+0x24/0x30 net/ipv6/addrconf_core.c:109 addrconf_ifdown+0xe5e/0x1ab0 net/ipv6/addrconf.c:3948 addrconf_notify+0x32f/0xe10 net/ipv6/addrconf.c:-1 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0x8c/0xf0 kernel/notifier.c:455 __dev_notify_flags+0x304/0x610 net/core/dev.c:-1 dev_change_flags+0xf0/0x1a0 net/core/dev.c:8687 dev_ifsioc+0x177/0x1150 net/core/dev_ioctl.c:327 dev_ioctl+0x543/0xe60 net/core/dev_ioctl.c:588 sock_do_ioctl+0x26b/0x450 net/socket.c:1208 sock_ioctl+0x455/0x740 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0x114/0x190 fs/ioctl.c:856 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:856 x64_sys_call+0x98/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:17 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff888131e9ab00 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 0 bytes inside of 96-byte region [ffff888131e9ab00, ffff888131e9ab60) The buggy address belongs to the physical page: page:ffffea0004c7a680 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x131e9a flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 ffffea00043403c0 dead000000000007 ffff888100042900 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 0x112a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 5209, tgid 5208 (syz.1.1312), ts 200904620845, free_ts 200891474442 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x213/0x220 mm/page_alloc.c:2637 prep_new_page+0x1b/0x110 mm/page_alloc.c:2644 get_page_from_freelist+0x3a98/0x3b10 mm/page_alloc.c:4539 __alloc_pages+0x234/0x610 mm/page_alloc.c:5837 alloc_slab_page+0x6c/0xf0 include/linux/gfp.h:-1 allocate_slab mm/slub.c:1962 [inline] new_slab+0x90/0x3e0 mm/slub.c:2015 ___slab_alloc+0x6f9/0xb80 mm/slub.c:3203 __slab_alloc+0x5d/0xa0 mm/slub.c:3302 slab_alloc_node mm/slub.c:3387 [inline] __kmem_cache_alloc_node+0x207/0x2a0 mm/slub.c:3462 kmalloc_trace+0x2a/0xa0 mm/slab_common.c:1028 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] nf_nat_masq_schedule+0x2d1/0x600 net/netfilter/nf_nat_masquerade.c:118 masq_inet6_event+0x124/0x180 net/netfilter/nf_nat_masquerade.c:295 notifier_call_chain kernel/notifier.c:87 [inline] atomic_notifier_call_chain+0x95/0x100 kernel/notifier.c:225 inet6addr_notifier_call_chain+0x24/0x30 net/ipv6/addrconf_core.c:109 addrconf_ifdown+0xe5e/0x1ab0 net/ipv6/addrconf.c:3948 addrconf_notify+0x32f/0xe10 net/ipv6/addrconf.c:-1 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1545 [inline] free_pcp_prepare mm/page_alloc.c:1619 [inline] free_unref_page_prepare+0x9f1/0xa00 mm/page_alloc.c:3581 free_unref_page+0xb2/0x5c0 mm/page_alloc.c:3677 free_the_page mm/page_alloc.c:830 [inline] __free_pages+0x61/0xf0 mm/page_alloc.c:5926 free_pages+0x7c/0x90 mm/page_alloc.c:5937 tlb_batch_list_free mm/mmu_gather.c:75 [inline] tlb_finish_mmu+0x311/0x3f0 mm/mmu_gather.c:364 exit_mmap+0x45b/0xbb0 mm/mmap.c:3359 __mmput+0x95/0x310 kernel/fork.c:1299 mmput+0x56/0x170 kernel/fork.c:1322 copy_process+0x2242/0x3530 kernel/fork.c:2637 kernel_clone+0x229/0x890 kernel/fork.c:2785 __do_sys_clone kernel/fork.c:2928 [inline] __se_sys_clone kernel/fork.c:2912 [inline] __x64_sys_clone+0x231/0x280 kernel/fork.c:2912 x64_sys_call+0x1b0/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:57 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Memory state around the buggy address: ffff888131e9aa00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888131e9aa80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff888131e9ab00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff888131e9ab80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888131e9ac00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ================================================================== general protection fault, probably for non-canonical address 0xdffffc0000000044: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000220-0x0000000000000227] CPU: 0 PID: 6403 Comm: syz.2.1637 Tainted: G B 6.1.129-syzkaller-00051-gc1fd50266bd6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:__xdp_enqueue kernel/bpf/devmap.c:481 [inline] RIP: 0010:dev_map_enqueue+0x91/0x340 kernel/bpf/devmap.c:534 Code: d0 00 00 00 4c 89 e8 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 ef e8 9f 9e 25 00 bb 20 02 00 00 49 03 5d 00 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 80 9e 25 00 48 83 3b 00 0f 84 eb RSP: 0018:ffffc90000c075f8 EFLAGS: 00010206 RAX: 0000000000000044 RBX: 0000000000000220 RCX: ffffffff8197a441 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888130e5fed0 RBP: ffffc90000c07638 R08: ffffffff8144b443 R09: fffffbfff0f6e8fd R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: ffff888130e5fed0 R14: ffff888130e5fe00 R15: ffff888122e62070 FS: 00007fcdae3de6c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000001214d9000 CR4: 00000000003506b0 DR0: 0010000010000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __xdp_do_redirect_frame net/core/filter.c:4319 [inline] xdp_do_redirect_frame+0x2b5/0x800 net/core/filter.c:4381 xdp_test_run_batch net/bpf/test_run.c:314 [inline] bpf_test_run_xdp_live+0xc30/0x1f70 net/bpf/test_run.c:362 bpf_prog_test_run_xdp+0x7d1/0x1130 net/bpf/test_run.c:1393 bpf_prog_test_run+0x3b0/0x630 kernel/bpf/syscall.c:3670 __sys_bpf+0x59f/0x7f0 kernel/bpf/syscall.c:5025 __do_sys_bpf kernel/bpf/syscall.c:5111 [inline] __se_sys_bpf kernel/bpf/syscall.c:5109 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5109 x64_sys_call+0x87f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:322 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fcdae58d169 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:00007fcdae3de038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fcdae7a6080 RCX: 00007fcdae58d169 RDX: 0000000000000050 RSI: 00002000000000c0 RDI: 000000000000000a RBP: 00007fcdae60e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fcdae7a6080 R15: 00007ffc74d143a8 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:__xdp_enqueue kernel/bpf/devmap.c:481 [inline] RIP: 0010:dev_map_enqueue+0x91/0x340 kernel/bpf/devmap.c:534 Code: d0 00 00 00 4c 89 e8 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 ef e8 9f 9e 25 00 bb 20 02 00 00 49 03 5d 00 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 80 9e 25 00 48 83 3b 00 0f 84 eb RSP: 0018:ffffc90000c075f8 EFLAGS: 00010206 RAX: 0000000000000044 RBX: 0000000000000220 RCX: ffffffff8197a441 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888130e5fed0 RBP: ffffc90000c07638 R08: ffffffff8144b443 R09: fffffbfff0f6e8fd R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: ffff888130e5fed0 R14: ffff888130e5fe00 R15: ffff888122e62070 FS: 00007fcdae3de6c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000001214d9000 CR4: 00000000003506b0 DR0: 0010000010000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 ---------------- Code disassembly (best guess): 0: d0 00 rolb (%rax) 2: 00 00 add %al,(%rax) 4: 4c 89 e8 mov %r13,%rax 7: 48 c1 e8 03 shr $0x3,%rax b: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) 10: 74 08 je 0x1a 12: 4c 89 ef mov %r13,%rdi 15: e8 9f 9e 25 00 call 0x259eb9 1a: bb 20 02 00 00 mov $0x220,%ebx 1f: 49 03 5d 00 add 0x0(%r13),%rbx 23: 48 89 d8 mov %rbx,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) <-- trapping instruction 2f: 74 08 je 0x39 31: 48 89 df mov %rbx,%rdi 34: e8 80 9e 25 00 call 0x259eb9 39: 48 83 3b 00 cmpq $0x0,(%rbx) 3d: 0f .byte 0xf 3e: 84 eb test %ch,%bl