Kernel bug: KASAN: stack-out-of-bounds Read in xdp_do_check_flushed
Subsystem: bpf, net
Status: fixed

Crash report:
==================================================================
BUG: KASAN: stack-out-of-bounds in bpf_net_ctx_get_all_used_flush_lists include/linux/filter.h:837 [inline]
BUG: KASAN: stack-out-of-bounds in xdp_do_check_flushed+0x231/0x240 net/core/filter.c:4298
Read of size 4 at addr ffffc9000abdf7f8 by task syz-executor176/8754

CPU: 0 UID: 0 PID: 8754 Comm: syz-executor176 Not tainted 6.10.0-syzkaller-12246-g786c8248dbd3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 bpf_net_ctx_get_all_used_flush_lists include/linux/filter.h:837 [inline]
 xdp_do_check_flushed+0x231/0x240 net/core/filter.c:4298
 __napi_poll+0xe4/0x490 net/core/dev.c:6774
 napi_poll net/core/dev.c:6840 [inline]
 net_rx_action+0x89b/0x1240 net/core/dev.c:6962
 handle_softirqs+0x2c6/0x970 kernel/softirq.c:554
 do_softirq+0x11b/0x1e0 kernel/softirq.c:455
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 tun_get_user+0x2884/0x4720 drivers/net/tun.c:1936
 tun_chr_write_iter+0x113/0x1f0 drivers/net/tun.c:2052
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0xa74/0xc90 fs/read_write.c:590
 ksys_write+0x1a0/0x2c0 fs/read_write.c:643
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4f5d977d90
Code: 40 00 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 80 3d 11 e3 07 00 00 74 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 48 89
RSP: 002b:00007ffcd37e87b8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4f5d977d90
RDX: 0000000000000e80 RSI: 0000000020000340 RDI: 00000000000000c8
RBP: 0000000000000000 R08: 00007ffcd37e88e8 R09: 00007ffcd37e88e8
R10: 00007ffcd37e88e8 R11: 0000000000000202 R12: 0000000000000000
R13: 00007ffcd37e87d4 R14: 00007ffcd37e87f0 R15: 00007ffcd37e87e0
 </TASK>

The buggy address belongs to stack of task syz-executor176/8754
 and is located at offset 88 in frame:
 do_softirq+0x0/0x1e0

This frame has 2 objects:
 [32, 40) 'flags.i.i.i105'
 [64, 72) 'flags.i.i.i'

The buggy address belongs to the virtual mapping at
 [ffffc9000abd8000, ffffc9000abe1000) created by:
 copy_process+0x5d1/0x3dc0 kernel/fork.c:2204

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2bc2d
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 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 0x2dc2(GFP_KERNEL|__GFP_HIGHMEM|__GFP_NOWARN|__GFP_ZERO), pid 5092, tgid 5092 (syz-executor176), ts 123434607937, free_ts 123308629606
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1493
 prep_new_page mm/page_alloc.c:1501 [inline]
 get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3438
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4696
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2263
 vm_area_alloc_pages mm/vmalloc.c:3584 [inline]
 __vmalloc_area_node mm/vmalloc.c:3660 [inline]
 __vmalloc_node_range_noprof+0x971/0x1460 mm/vmalloc.c:3841
 alloc_thread_stack_node kernel/fork.c:313 [inline]
 dup_task_struct+0x444/0x8c0 kernel/fork.c:1113
 copy_process+0x5d1/0x3dc0 kernel/fork.c:2204
 kernel_clone+0x226/0x8f0 kernel/fork.c:2781
 __do_sys_clone kernel/fork.c:2924 [inline]
 __se_sys_clone kernel/fork.c:2908 [inline]
 __x64_sys_clone+0x258/0x2a0 kernel/fork.c:2908
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 8738 tgid 8738 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1094 [inline]
 free_unref_folios+0x103a/0x1b00 mm/page_alloc.c:2656
 folios_put_refs+0x76e/0x860 mm/swap.c:1039
 free_pages_and_swap_cache+0x5c8/0x690 mm/swap_state.c:335
 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
 tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:366 [inline]
 tlb_flush_mmu+0x3a3/0x680 mm/mmu_gather.c:373
 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:465
 exit_mmap+0x44f/0xc80 mm/mmap.c:3395
 __mmput+0x115/0x390 kernel/fork.c:1345
 exit_mm+0x220/0x310 kernel/exit.c:571
 do_exit+0x9b2/0x27f0 kernel/exit.c:869
 do_group_exit+0x207/0x2c0 kernel/exit.c:1031
 __do_sys_exit_group kernel/exit.c:1042 [inline]
 __se_sys_exit_group kernel/exit.c:1040 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1040
 x64_sys_call+0x26c3/0x26d0 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffffc9000abdf680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc9000abdf700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc9000abdf780: 00 00 00 00 f1 f1 f1 f1 00 f2 f2 f2 00 f3 f3 f3
                                                                ^
 ffffc9000abdf800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc9000abdf880: f1 f1 f1 f1 00 f3 f3 f3 00 00 00 00 00 00 00 00
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