================================================================== BUG: KASAN: use-after-free in dev_map_generic_redirect+0x9f/0x7d0 kernel/bpf/devmap.c:668 Read of size 8 at addr ffff88811a653c00 by task syz.6.12960/30349 CPU: 0 PID: 30349 Comm: syz.6.12960 Tainted: G W 6.1.118-syzkaller-00023-g092a580916f8 #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+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_generic_redirect+0x9f/0x7d0 kernel/bpf/devmap.c:668 xdp_do_generic_redirect_map net/core/filter.c:4392 [inline] xdp_do_generic_redirect+0x42e/0xb40 net/core/filter.c:4451 do_xdp_generic+0x53e/0x800 net/core/dev.c:4966 tun_get_user+0x238a/0x3a90 drivers/net/tun.c:1920 tun_chr_write_iter+0x129/0x210 drivers/net/tun.c:2044 call_write_iter include/linux/fs.h:2274 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0xaf6/0xed0 fs/read_write.c:584 ksys_write+0x199/0x2c0 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+0x2f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:2 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: 0033:0x7f49a678b7df 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:00007f49a752d000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f49a69a5fa0 RCX: 00007f49a678b7df RDX: 000000000000fe53 RSI: 0000000020000440 RDI: 00000000000000c8 RBP: 00007f49a680e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000fe53 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f49a69a5fa0 R15: 00007ffe4ff8a0f8 Allocated by task 29588: 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:583 [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:4990 __do_sys_bpf kernel/bpf/syscall.c:5106 [inline] __se_sys_bpf kernel/bpf/syscall.c:5104 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5104 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 17230: 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+0x596/0x6c0 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:3929 addrconf_notify+0x32f/0xe10 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0x8c/0xf0 kernel/notifier.c:455 __dev_notify_flags+0x304/0x610 dev_change_flags+0xf0/0x1a0 net/core/dev.c:8685 do_setlink+0xdb8/0x4050 net/core/rtnetlink.c:2830 rtnl_group_changelink net/core/rtnetlink.c:3358 [inline] __rtnl_newlink net/core/rtnetlink.c:3615 [inline] rtnl_newlink+0x10cc/0x2030 net/core/rtnetlink.c:3652 rtnetlink_rcv_msg+0x9a5/0xca0 net/core/rtnetlink.c:6150 netlink_rcv_skb+0x1cd/0x410 net/netlink/af_netlink.c:2518 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6168 netlink_unicast_kernel net/netlink/af_netlink.c:1327 [inline] netlink_unicast+0x906/0xab0 net/netlink/af_netlink.c:1353 netlink_sendmsg+0xa15/0xd30 net/netlink/af_netlink.c:1875 sock_sendmsg_nosec net/socket.c:716 [inline] __sock_sendmsg net/socket.c:728 [inline] ____sys_sendmsg+0x5d3/0x9a0 net/socket.c:2509 ___sys_sendmsg net/socket.c:2563 [inline] __sys_sendmsg+0x2a9/0x390 net/socket.c:2592 __do_sys_sendmsg net/socket.c:2601 [inline] __se_sys_sendmsg net/socket.c:2599 [inline] __x64_sys_sendmsg+0x7f/0x90 net/socket.c:2599 x64_sys_call+0x16a/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:47 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 Second to 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 __call_rcu_common kernel/rcu/tree.c:2807 [inline] call_rcu+0xdc/0x10f0 kernel/rcu/tree.c:2926 release_probes kernel/tracepoint.c:164 [inline] tracepoint_remove_func kernel/tracepoint.c:458 [inline] tracepoint_probe_unregister+0x82b/0x900 kernel/tracepoint.c:551 bpf_probe_unregister+0x61/0x70 kernel/trace/bpf_trace.c:2347 bpf_raw_tp_link_release+0x63/0x90 kernel/bpf/syscall.c:3170 bpf_link_free+0x129/0x3f0 kernel/bpf/syscall.c:2744 bpf_link_put kernel/bpf/syscall.c:2770 [inline] bpf_link_release+0x170/0x180 kernel/bpf/syscall.c:2779 __fput+0x1e5/0x870 fs/file_table.c:320 ____fput+0x15/0x20 fs/file_table.c:348 task_work_run+0x24d/0x2e0 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0x94/0xa0 kernel/entry/common.c:177 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x26/0x130 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 ffff88811a653c00 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 0 bytes inside of 96-byte region [ffff88811a653c00, ffff88811a653c60) The buggy address belongs to the physical page: page:ffffea00046994c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88811a653400 pfn:0x11a653 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 ffffea00045bc908 ffffea00043c99c8 ffff888100042900 raw: ffff88811a653400 0000000000200016 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 102, tgid 102 (udevd), ts 6031248654, free_ts 0 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x213/0x220 mm/page_alloc.c:2590 prep_new_page+0x1b/0x110 mm/page_alloc.c:2597 get_page_from_freelist+0x2f41/0x2fc0 mm/page_alloc.c:4462 __alloc_pages+0x234/0x610 mm/page_alloc.c:5759 alloc_slab_page+0x6c/0xf0 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:557 [inline] kzalloc include/linux/slab.h:693 [inline] kernfs_get_open_node fs/kernfs/file.c:574 [inline] kernfs_fop_open+0x70e/0xb10 fs/kernfs/file.c:742 do_dentry_open+0x891/0x1250 fs/open.c:884 vfs_open+0x73/0x80 fs/open.c:1015 do_open fs/namei.c:3625 [inline] path_openat+0x2532/0x2d60 fs/namei.c:3782 do_filp_open+0x230/0x480 fs/namei.c:3809 do_sys_openat2+0x151/0x870 fs/open.c:1341 page_owner free stack trace missing Memory state around the buggy address: ffff88811a653b00: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc ffff88811a653b80: 00 00 00 00 00 00 00 00 01 fc fc fc fc fc fc fc >ffff88811a653c00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff88811a653c80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff88811a653d00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc 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