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: 1 UID: 0 PID: 1452 Comm: kworker/1:2 Not tainted 6.12.0-syzkaller-11716-gd8b78066f4c9 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: events mptcp_worker RIP: 0010:_compound_head include/linux/page-flags.h:242 [inline] RIP: 0010:put_page+0x21/0x280 include/linux/mm.h:1552 Code: 90 90 90 90 90 90 90 90 90 41 54 55 53 48 89 fb e8 c4 57 a2 f8 48 8d 7b 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 20 02 00 00 4c 8b 63 08 31 ff 4c 89 e5 83 e5 01 RSP: 0018:ffffc9000783f568 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff88ed3088 RDX: 0000000000000001 RSI: ffffffff88eba7cc RDI: 0000000000000008 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000004 R12: ffff8880265f1680 R13: ffff888025df6540 R14: ffff888025df6570 R15: 0000000000000007 FS: 0000000000000000(0000) GS:ffff88802b500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000006dfaa000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: skb_page_unref include/linux/skbuff_ref.h:43 [inline] __skb_frag_unref include/linux/skbuff_ref.h:56 [inline] skb_release_data+0x4d7/0x730 net/core/skbuff.c:1119 skb_release_all net/core/skbuff.c:1190 [inline] __kfree_skb+0x4f/0x70 net/core/skbuff.c:1204 tcp_wmem_free_skb include/net/tcp.h:306 [inline] tcp_rtx_queue_unlink_and_free include/net/tcp.h:2091 [inline] tcp_clean_rtx_queue net/ipv4/tcp_input.c:3436 [inline] tcp_ack+0x1eb7/0x5ba0 net/ipv4/tcp_input.c:4032 tcp_rcv_state_process+0xdd4/0x4c40 net/ipv4/tcp_input.c:6805 tcp_v4_do_rcv+0x1ad/0xa90 net/ipv4/tcp_ipv4.c:1939 sk_backlog_rcv include/net/sock.h:1121 [inline] __release_sock+0x31b/0x400 net/core/sock.c:3083 __tcp_close+0x4f3/0xff0 net/ipv4/tcp.c:3143 __mptcp_close_ssk+0x331/0x14e0 net/mptcp/protocol.c:2495 mptcp_close_ssk net/mptcp/protocol.c:2549 [inline] mptcp_close_ssk+0x150/0x220 net/mptcp/protocol.c:2532 __mptcp_close_subflow net/mptcp/protocol.c:2577 [inline] mptcp_worker+0x824/0x1240 net/mptcp/protocol.c:2790 process_one_work+0x958/0x1b30 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:_compound_head include/linux/page-flags.h:242 [inline] RIP: 0010:put_page+0x21/0x280 include/linux/mm.h:1552 Code: 90 90 90 90 90 90 90 90 90 41 54 55 53 48 89 fb e8 c4 57 a2 f8 48 8d 7b 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 20 02 00 00 4c 8b 63 08 31 ff 4c 89 e5 83 e5 01 RSP: 0018:ffffc9000783f568 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff88ed3088 RDX: 0000000000000001 RSI: ffffffff88eba7cc RDI: 0000000000000008 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000004 R12: ffff8880265f1680 R13: ffff888025df6540 R14: ffff888025df6570 R15: 0000000000000007 FS: 0000000000000000(0000) GS:ffff88802b500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000040 CR3: 000000006190c000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 90 nop 1: 90 nop 2: 90 nop 3: 90 nop 4: 90 nop 5: 90 nop 6: 90 nop 7: 90 nop 8: 90 nop 9: 41 54 push %r12 b: 55 push %rbp c: 53 push %rbx d: 48 89 fb mov %rdi,%rbx 10: e8 c4 57 a2 f8 call 0xf8a257d9 15: 48 8d 7b 08 lea 0x8(%rbx),%rdi 19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 20: fc ff df 23: 48 89 fa mov %rdi,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx * 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction 2e: 0f 85 20 02 00 00 jne 0x254 34: 4c 8b 63 08 mov 0x8(%rbx),%r12 38: 31 ff xor %edi,%edi 3a: 4c 89 e5 mov %r12,%rbp 3d: 83 e5 01 and $0x1,%ebp