================================================================== BUG: KASAN: use-after-free in dev_map_generic_redirect+0xa0/0x650 kernel/bpf/devmap.c:668 Read of size 8 at addr ffff8880581a0880 by task syz.6.1020/7429 CPU: 1 PID: 7429 Comm: syz.6.1020 Not tainted 6.1.115-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15f/0x4f0 mm/kasan/report.c:395 kasan_report+0x136/0x160 mm/kasan/report.c:495 dev_map_generic_redirect+0xa0/0x650 kernel/bpf/devmap.c:668 xdp_do_generic_redirect_map net/core/filter.c:4392 [inline] xdp_do_generic_redirect+0x4bf/0x850 net/core/filter.c:4451 do_xdp_generic+0x50b/0x6d0 net/core/dev.c:4951 tun_get_user+0x261e/0x42d0 drivers/net/tun.c:1920 tun_chr_write_iter+0x10c/0x1f0 drivers/net/tun.c:2044 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x857/0xbc0 fs/read_write.c:584 ksys_write+0x19c/0x2c0 fs/read_write.c:637 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: 0033:0x7fbfe7b7d1ff Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 c9 8d 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 1c 8e 02 00 48 RSP: 002b:00007fbfe89b3000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fbfe7d35f80 RCX: 00007fbfe7b7d1ff RDX: 0000000000000d86 RSI: 0000000020002340 RDI: 00000000000000c8 RBP: 00007fbfe7bf139e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000d86 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fbfe7d35f80 R15: 00007ffe436ba3c8 Allocated by task 6992: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x97/0xb0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:557 [inline] kzalloc include/linux/slab.h:693 [inline] get_undo_list ipc/sem.c:1856 [inline] copy_semundo+0xb1/0x230 ipc/sem.c:2314 copy_process+0x1848/0x4060 kernel/fork.c:2249 kernel_clone+0x222/0x920 kernel/fork.c:2679 __do_sys_clone3 kernel/fork.c:2978 [inline] __se_sys_clone3+0x373/0x410 kernel/fork.c:2962 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 6993: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook mm/slub.c:1750 [inline] slab_free mm/slub.c:3661 [inline] __kmem_cache_free+0x25c/0x3c0 mm/slub.c:3674 exit_sem+0x197a/0x19e0 ipc/sem.c:2447 do_exit+0xa44/0x26a0 kernel/exit.c:864 do_group_exit+0x202/0x2b0 kernel/exit.c:1021 get_signal+0x16f7/0x17d0 kernel/signal.c:2870 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff8880581a0880 which belongs to the cache kmalloc-cg-96 of size 96 The buggy address is located 0 bytes inside of 96-byte region [ffff8880581a0880, ffff8880581a08e0) The buggy address belongs to the physical page: page:ffffea0001606800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x581a0 memcg:ffff888028d7bc01 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea000062a880 dead000000000003 ffff888017c428c0 raw: 0000000000000000 0000000000200020 00000001ffffffff ffff888028d7bc01 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 4250, tgid 4250 (syz-executor), ts 78787807613, free_ts 20480814472 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2517 prep_new_page mm/page_alloc.c:2524 [inline] get_page_from_freelist+0x322e/0x33b0 mm/page_alloc.c:4290 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5558 alloc_slab_page+0x6a/0x150 mm/slub.c:1794 allocate_slab mm/slub.c:1939 [inline] new_slab+0x84/0x2d0 mm/slub.c:1992 ___slab_alloc+0xc20/0x1270 mm/slub.c:3180 __slab_alloc mm/slub.c:3279 [inline] slab_alloc_node mm/slub.c:3364 [inline] __kmem_cache_alloc_node+0x19f/0x260 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc_node+0xa2/0x230 mm/slab_common.c:943 kmalloc_node include/linux/slab.h:583 [inline] kvmalloc_node+0x6e/0x180 mm/util.c:581 kvmalloc include/linux/slab.h:710 [inline] kvzalloc include/linux/slab.h:718 [inline] allocate_hook_entries_size net/netfilter/core.c:61 [inline] nf_hook_entries_grow+0x331/0x760 net/netfilter/core.c:128 __nf_register_net_hook+0x29c/0x930 net/netfilter/core.c:423 nf_register_net_hook+0xac/0x180 net/netfilter/core.c:566 nf_register_net_hooks+0x3d/0x1a0 net/netfilter/core.c:582 ip6t_register_table+0x4d0/0x7b0 net/ipv6/netfilter/ip6_tables.c:1789 ip6table_mangle_table_init+0x3e/0x60 net/ipv6/netfilter/ip6table_mangle.c:84 xt_find_table_lock+0x2cc/0x3a0 net/netfilter/x_tables.c:1259 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1444 [inline] free_pcp_prepare mm/page_alloc.c:1494 [inline] free_unref_page_prepare+0xf63/0x1120 mm/page_alloc.c:3369 free_unref_page+0x33/0x3e0 mm/page_alloc.c:3464 free_contig_range+0x9a/0x150 mm/page_alloc.c:9518 destroy_args+0xfe/0x997 mm/debug_vm_pgtable.c:1031 debug_vm_pgtable+0x416/0x46b mm/debug_vm_pgtable.c:1354 do_one_initcall+0x265/0x8f0 init/main.c:1298 do_initcall_level+0x157/0x207 init/main.c:1371 do_initcalls+0x49/0x86 init/main.c:1387 kernel_init_freeable+0x45c/0x60f init/main.c:1626 kernel_init+0x19/0x290 init/main.c:1514 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Memory state around the buggy address: ffff8880581a0780: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8880581a0800: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff8880581a0880: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff8880581a0900: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ffff8880581a0980: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ==================================================================