syzbot

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BUG: KASAN: use-after-free in dev_map_generic_redirect+0xa0/0x650 kernel/bpf/devmap.c:665
Read of size 8 at addr ffff888057879600 by task syz.1.2304/10902

CPU: 0 PID: 10902 Comm: syz.1.2304 Not tainted 6.1.110-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 <TASK>
 __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:665
 xdp_do_generic_redirect_map net/core/filter.c:4390 [inline]
 xdp_do_generic_redirect+0x4bf/0x850 net/core/filter.c:4449
 do_xdp_generic+0x50b/0x6d0 net/core/dev.c:4947
 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: 0033:0x7f46e397c9df
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:00007f46e4771000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f46e3b35f80 RCX: 00007f46e397c9df
RDX: 000000000000fdef RSI: 00000000200000c0 RDI: 00000000000000c8
RBP: 00007f46e39f0b76 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000fdef R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f46e3b35f80 R15: 00007ffd9befa2b8
 </TASK>

Allocated by task 10696:
 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
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 __do_kmalloc_node mm/slab_common.c:936 [inline]
 __kmalloc_node+0xb3/0x230 mm/slab_common.c:943
 kmalloc_node include/linux/slab.h:583 [inline]
 bpf_map_kmalloc_node+0xce/0x1c0 kernel/bpf/syscall.c:452
 __dev_map_alloc_node+0x56/0x4d0 kernel/bpf/devmap.c:848
 __dev_map_update_elem kernel/bpf/devmap.c:913 [inline]
 dev_map_update_elem+0x1eb/0x3c0 kernel/bpf/devmap.c:932
 bpf_map_update_value+0x5cf/0x6f0 kernel/bpf/syscall.c:226
 map_update_elem+0x503/0x680 kernel/bpf/syscall.c:1463
 __sys_bpf+0x337/0x6c0 kernel/bpf/syscall.c:5008
 __do_sys_bpf kernel/bpf/syscall.c:5124 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5122 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5122
 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 3690:
 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
 dev_map_free+0x56c/0x680 kernel/bpf/devmap.c:238
 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 ffff888057879600
 which belongs to the cache kmalloc-cg-96 of size 96
The buggy address is located 0 bytes inside of
 96-byte region [ffff888057879600, ffff888057879660)

The buggy address belongs to the physical page:
page:ffffea00015e1e40 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888057879f80 pfn:0x57879
memcg:ffff8880197caa01
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea0000b30900 dead000000000003 ffff888017c428c0
raw: ffff888057879f80 000000008020001f 00000001ffffffff ffff8880197caa01
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 3993, tgid 3993 (syz.3.120), ts 86789437202, free_ts 86693423834
 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
 kmalloc_trace+0x26/0xe0 mm/slab_common.c:1026
 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:2252
 kernel_clone+0x222/0x920 kernel/fork.c:2682
 __do_sys_clone3 kernel/fork.c:2981 [inline]
 __se_sys_clone3+0x373/0x410 kernel/fork.c:2965
 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
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_list+0x663/0x900 mm/page_alloc.c:3510
 release_pages+0x2836/0x2b40 mm/swap.c:1055
 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:254 [inline]
 tlb_flush_mmu+0xfc/0x210 mm/mmu_gather.c:261
 tlb_finish_mmu+0xce/0x1f0 mm/mmu_gather.c:361
 exit_mmap+0x3c3/0x9f0 mm/mmap.c:3239
 __mmput+0x115/0x3c0 kernel/fork.c:1199
 exit_mm+0x226/0x300 kernel/exit.c:565
 do_exit+0x9f6/0x26a0 kernel/exit.c:858
 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

Memory state around the buggy address:
 ffff888057879500: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff888057879580: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff888057879600: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                   ^
 ffff888057879680: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff888057879700: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
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