syzbot

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BUG: KASAN: use-after-free in dev_map_generic_redirect+0x9f/0x7d0 kernel/bpf/devmap.c:665
Read of size 8 at addr ffff888111b59780 by task syz.1.22/405

CPU: 0 PID: 405 Comm: syz.1.22 Not tainted 6.1.112-syzkaller-00008-g38859a233e31 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __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:665
 xdp_do_generic_redirect_map net/core/filter.c:4390 [inline]
 xdp_do_generic_redirect+0x42e/0xb40 net/core/filter.c:4449
 do_xdp_generic+0x53e/0x800 net/core/dev.c:4958
 __netif_receive_skb_core+0x19ae/0x43d0 net/core/dev.c:5365
 __netif_receive_skb_one_core net/core/dev.c:5542 [inline]
 __netif_receive_skb+0x11c/0x530 net/core/dev.c:5658
 netif_receive_skb_internal net/core/dev.c:5744 [inline]
 netif_receive_skb+0xb0/0x480 net/core/dev.c:5803
 tun_rx_batched+0x1c0/0x8f0 drivers/net/tun.c:1548
 tun_get_user+0x287e/0x3a90 drivers/net/tun.c:1998
 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: 0033:0x7f57bb77d1ff
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:00007f57bc501000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f57bb935f80 RCX: 00007f57bb77d1ff
RDX: 000000000000006a RSI: 0000000020000180 RDI: 00000000000000c8
RBP: 00007f57bb7f1616 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000006a R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f57bb935f80 R15: 00007ffc90d8cc68
 </TASK>

Allocated by task 398:
 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:848
 __dev_map_update_elem kernel/bpf/devmap.c:913 [inline]
 dev_map_update_elem+0x20e/0x3f0 kernel/bpf/devmap.c:932
 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 357:
 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:3684 [inline]
 __kmem_cache_free+0x218/0x3b0 mm/slub.c:3697
 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

The buggy address belongs to the object at ffff888111b59780
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 0 bytes inside of
 96-byte region [ffff888111b59780, ffff888111b597e0)

The buggy address belongs to the physical page:
page:ffffea000446d640 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x111b59
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 0000000000000000 dead000000000122 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 393, tgid 393 (kworker/0:3), ts 34338720822, free_ts 32745095065
 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+0x2980/0x2a10 mm/page_alloc.c:4439
 __alloc_pages+0x234/0x610 mm/page_alloc.c:5728
 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+0x1af/0x250 mm/slub.c:3460
 kmalloc_trace+0x2a/0xa0 mm/slab_common.c:1028
 kmalloc include/linux/slab.h:557 [inline]
 dst_cow_metrics_generic+0x55/0x1c0 net/core/dst.c:199
 dst_metrics_write_ptr include/net/dst.h:119 [inline]
 dst_metric_set include/net/dst.h:180 [inline]
 icmp6_dst_alloc+0x363/0x510 net/ipv6/route.c:3282
 mld_sendpack+0x614/0xe40 net/ipv6/mcast.c:1809
 mld_send_initial_cr net/ipv6/mcast.c:2239 [inline]
 ipv6_mc_dad_complete+0x283/0x5e0 net/ipv6/mcast.c:2247
 addrconf_dad_completed+0x6d5/0xdb0 net/ipv6/addrconf.c:4282
 addrconf_dad_work+0xd95/0x16b0
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1498 [inline]
 free_pcp_prepare mm/page_alloc.c:1572 [inline]
 free_unref_page_prepare+0x83d/0x850 mm/page_alloc.c:3511
 free_unref_page+0xb2/0x5c0 mm/page_alloc.c:3607
 free_the_page mm/page_alloc.c:798 [inline]
 __free_pages+0x61/0xf0 mm/page_alloc.c:5817
 __vunmap+0x9f3/0xb60 mm/vmalloc.c:2728
 __vfree mm/vmalloc.c:2776 [inline]
 vfree+0x5c/0x80 mm/vmalloc.c:2807
 kcov_put kernel/kcov.c:437 [inline]
 kcov_close+0x2b/0x50 kernel/kcov.c:533
 __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
 exit_task_work include/linux/task_work.h:39 [inline]
 do_exit+0xbd5/0x2b80 kernel/exit.c:877
 do_group_exit+0x21a/0x2d0 kernel/exit.c:1027
 get_signal+0x169d/0x1820 kernel/signal.c:2888
 arch_do_signal_or_restart+0xb0/0x16f0 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x74/0xa0 kernel/entry/common.c:174
 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

Memory state around the buggy address:
 ffff888111b59680: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff888111b59700: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff888111b59780: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                   ^
 ffff888111b59800: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
 ffff888111b59880: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
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