================================================================== BUG: KASAN: use-after-free in dev_map_generic_redirect+0xa0/0x650 kernel/bpf/devmap.c:668 Read of size 8 at addr ffff888028cab800 by task syz.1.1525/8897 CPU: 1 PID: 8897 Comm: syz.1.1525 Not tainted 6.1.128-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 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:316 [inline] print_report+0x15f/0x4f0 mm/kasan/report.c:427 kasan_report+0x136/0x160 mm/kasan/report.c:531 dev_map_generic_redirect+0xa0/0x650 kernel/bpf/devmap.c:668 xdp_do_generic_redirect_map net/core/filter.c:4416 [inline] xdp_do_generic_redirect+0x4bf/0x850 net/core/filter.c:4475 do_xdp_generic+0x50b/0x6d0 net/core/dev.c:4957 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: 0033:0x7fce1b98b85f Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 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 4c 93 02 00 48 RSP: 002b:00007fce1c74f000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fce1bba5fa0 RCX: 00007fce1b98b85f RDX: 000000000000fe53 RSI: 0000000020000440 RDI: 00000000000000c8 RBP: 00007fce1ba0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000fe53 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fce1bba5fa0 R15: 00007ffd5a1d0648 Allocated by task 7443: 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:563 [inline] kzalloc include/linux/slab.h:699 [inline] get_undo_list ipc/sem.c:1856 [inline] copy_semundo+0xb1/0x230 ipc/sem.c:2314 copy_process+0x1848/0x4060 kernel/fork.c:2251 kernel_clone+0x222/0x920 kernel/fork.c:2681 __do_sys_clone3 kernel/fork.c:2980 [inline] __se_sys_clone3+0x373/0x410 kernel/fork.c:2964 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 Last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:486 call_rcu+0x163/0xa10 kernel/rcu/tree.c:2845 nf_unregister_net_hooks+0xcc/0x130 net/netfilter/core.c:601 brnf_exit_net+0x68/0x130 net/bridge/br_netfilter_hooks.c:1308 ops_exit_list net/core/net_namespace.c:172 [inline] cleanup_net+0x7f1/0xd20 net/core/net_namespace.c:640 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the object at ffff888028cab800 which belongs to the cache kmalloc-cg-96 of size 96 The buggy address is located 0 bytes inside of 96-byte region [ffff888028cab800, ffff888028cab860) The buggy address belongs to the physical page: page:ffffea0000a32ac0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888028cab380 pfn:0x28cab memcg:ffff888019659401 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea000084b640 dead000000000002 ffff888017c428c0 raw: ffff888028cab380 0000000080200001 00000001ffffffff ffff888019659401 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 4253, tgid 4253 (syz-executor), ts 64120060949, free_ts 64119642998 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2532 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x3731/0x38d0 mm/page_alloc.c:4328 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5605 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:589 [inline] kvmalloc_node+0x6e/0x180 mm/util.c:581 kvmalloc include/linux/slab.h:716 [inline] alloc_fdtable+0x154/0x280 fs/file.c:138 dup_fd+0x95c/0xca0 fs/file.c:337 copy_files+0x72/0xe0 kernel/fork.c:1636 copy_process+0x1873/0x4060 kernel/fork.c:2254 kernel_clone+0x222/0x920 kernel/fork.c:2681 __do_sys_clone kernel/fork.c:2822 [inline] __se_sys_clone kernel/fork.c:2806 [inline] __x64_sys_clone+0x231/0x280 kernel/fork.c:2806 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare mm/page_alloc.c:1509 [inline] free_unref_page_prepare+0x12a6/0x15b0 mm/page_alloc.c:3384 free_unref_page+0x33/0x3e0 mm/page_alloc.c:3479 __vunmap+0x873/0xa30 mm/vmalloc.c:2718 __do_replace+0x891/0xa70 net/ipv6/netfilter/ip6_tables.c:1109 do_replace net/ipv6/netfilter/ip6_tables.c:1160 [inline] do_ip6t_set_ctl+0xef2/0x1250 net/ipv6/netfilter/ip6_tables.c:1646 nf_setsockopt+0x28a/0x2b0 net/netfilter/nf_sockopt.c:101 __sys_setsockopt+0x57e/0xa00 net/socket.c:2288 __do_sys_setsockopt net/socket.c:2299 [inline] __se_sys_setsockopt net/socket.c:2296 [inline] __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2296 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: ffff888028cab700: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888028cab780: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff888028cab800: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff888028cab880: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888028cab900: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ==================================================================