Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 UID: 0 PID: 5318 Comm: syz.0.0 Not tainted 6.13.0-rc3-syzkaller-00301-gbcde95ce32b6 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:_compound_head include/linux/page-flags.h:242 [inline] RIP: 0010:get_page include/linux/mm.h:1461 [inline] RIP: 0010:__skb_frag_ref+0x4d/0x1d0 include/linux/skbuff_ref.h:20 Code: 48 89 df e8 15 72 77 f8 4c 8b 33 31 c0 4c 89 f6 48 83 e6 01 4c 0f 45 f0 31 ff e8 2e 0f 11 f8 49 8d 5e 08 48 89 d8 48 c1 e8 03 <80> 3c 28 00 74 08 48 89 df e8 e5 71 77 f8 48 8b 1b 48 89 de 48 83 RSP: 0018:ffffc90000007840 EFLAGS: 00010202 RAX: 0000000000000001 RBX: 0000000000000008 RCX: ffff888032f1c880 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffffff898e69e2 R09: 1ffff110065c85ac R10: dffffc0000000000 R11: ffffed10065c85ad R12: dffffc0000000000 R13: ffff888032e42d70 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fb5f6be56c0(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb5ea9ff000 CR3: 0000000052888000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: skb_frag_ref include/linux/skbuff_ref.h:32 [inline] pskb_expand_head+0x74b/0x1380 net/core/skbuff.c:2300 __skb_unclone_keeptruesize+0x87/0x2c0 net/core/skbuff.c:2375 skb_unclone_keeptruesize include/linux/skbuff.h:1998 [inline] __tcp_retransmit_skb+0x58d/0x1500 net/ipv4/tcp_output.c:3376 tcp_send_loss_probe+0x426/0x8f0 net/ipv4/tcp_output.c:2982 tcp_write_timer+0x166/0x2e0 net/ipv4/tcp_timer.c:735 call_timer_fn+0x187/0x650 kernel/time/timer.c:1793 expire_timers kernel/time/timer.c:1844 [inline] __run_timers kernel/time/timer.c:2418 [inline] __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2430 run_timer_base kernel/time/timer.c:2439 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2449 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561 __do_softirq kernel/softirq.c:595 [inline] invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu+0xf7/0x220 kernel/softirq.c:662 irq_exit_rcu+0x9/0x30 kernel/softirq.c:678 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:unwind_next_frame+0x2ec/0x22d0 arch/x86/kernel/unwind_orc.c:494 Code: 48 8d 8c 11 50 28 27 90 4c 39 e1 0f 83 61 0d 00 00 48 c7 c0 50 28 27 90 49 29 c4 48 c7 c6 08 19 9b 90 49 c1 fc 02 4b 8d 14 64 <48> 01 d2 48 01 f2 0f 84 42 01 00 00 48 8d 5a 04 4c 8d 72 05 48 89 RSP: 0018:ffffc900019dee90 EFLAGS: 00000246 RAX: ffffffff90341d64 RBX: ffffffff90341d68 RCX: ffffffff90341d6c RDX: 0000000000000000 RSI: ffffffff90ae88ac RDI: ffffffff814ba930 RBP: ffffffff90341d68 R08: 0000000000000001 R09: ffffc900019df050 R10: ffffc900019defb0 R11: ffffffff818b3a20 R12: 0000000000000000 R13: ffffc900019def60 R14: ffffffff90341d6c R15: ffffffff81f830fb arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __set_page_owner+0x92/0x800 mm/page_owner.c:320 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1558 prep_new_page mm/page_alloc.c:1566 [inline] get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3476 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4753 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2269 folio_alloc_mpol_noprof+0x36/0x50 mm/mempolicy.c:2287 shmem_alloc_folio mm/shmem.c:1798 [inline] shmem_alloc_and_add_folio+0x4a0/0x1080 mm/shmem.c:1837 shmem_get_folio_gfp+0x621/0x1840 mm/shmem.c:2357 shmem_get_folio mm/shmem.c:2463 [inline] shmem_write_begin+0x165/0x350 mm/shmem.c:3119 generic_perform_write+0x346/0x990 mm/filemap.c:4055 shmem_file_write_iter+0xf9/0x120 mm/shmem.c:3295 new_sync_write fs/read_write.c:586 [inline] vfs_write+0xaeb/0xd30 fs/read_write.c:679 ksys_write+0x18f/0x2b0 fs/read_write.c:731 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: 0033:0x7fb5f5d847df 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:00007fb5f6be4df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007fb5f5d847df RDX: 0000000001000000 RSI: 00007fb5e9a00000 RDI: 000000000000000b RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000000062e7 R10: 00000000000007a8 R11: 0000000000000293 R12: 000000000000000b R13: 00007fb5f6be4ef0 R14: 00007fb5f6be4eb0 R15: 00007fb5e9a00000 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:_compound_head include/linux/page-flags.h:242 [inline] RIP: 0010:get_page include/linux/mm.h:1461 [inline] RIP: 0010:__skb_frag_ref+0x4d/0x1d0 include/linux/skbuff_ref.h:20 Code: 48 89 df e8 15 72 77 f8 4c 8b 33 31 c0 4c 89 f6 48 83 e6 01 4c 0f 45 f0 31 ff e8 2e 0f 11 f8 49 8d 5e 08 48 89 d8 48 c1 e8 03 <80> 3c 28 00 74 08 48 89 df e8 e5 71 77 f8 48 8b 1b 48 89 de 48 83 RSP: 0018:ffffc90000007840 EFLAGS: 00010202 RAX: 0000000000000001 RBX: 0000000000000008 RCX: ffff888032f1c880 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffffff898e69e2 R09: 1ffff110065c85ac R10: dffffc0000000000 R11: ffffed10065c85ad R12: dffffc0000000000 R13: ffff888032e42d70 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fb5f6be56c0(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb5ea9ff000 CR3: 0000000052888000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 48 89 df mov %rbx,%rdi 3: e8 15 72 77 f8 call 0xf877721d 8: 4c 8b 33 mov (%rbx),%r14 b: 31 c0 xor %eax,%eax d: 4c 89 f6 mov %r14,%rsi 10: 48 83 e6 01 and $0x1,%rsi 14: 4c 0f 45 f0 cmovne %rax,%r14 18: 31 ff xor %edi,%edi 1a: e8 2e 0f 11 f8 call 0xf8110f4d 1f: 49 8d 5e 08 lea 0x8(%r14),%rbx 23: 48 89 d8 mov %rbx,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 80 3c 28 00 cmpb $0x0,(%rax,%rbp,1) <-- trapping instruction 2e: 74 08 je 0x38 30: 48 89 df mov %rbx,%rdi 33: e8 e5 71 77 f8 call 0xf877721d 38: 48 8b 1b mov (%rbx),%rbx 3b: 48 89 de mov %rbx,%rsi 3e: 48 rex.W 3f: 83 .byte 0x83