general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 0 PID: 17549 Comm: syz-executor.0 Not tainted 5.7.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:qrtr_endpoint_post+0x92/0xfa0 net/qrtr/qrtr.c:440 Code: 44 89 e6 e8 80 27 4e fe 48 85 c0 48 89 c5 0f 84 57 0e 00 00 e8 4f 7a 9e f9 48 89 da 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <0f> b6 04 02 48 89 da 83 e2 07 38 d0 7f 08 84 c0 0f 85 f7 0c 00 00 RSP: 0018:ffffc900185dfc38 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000010 RCX: ffffc900022c1000 RDX: 0000000000000002 RSI: ffffffff87d55471 RDI: ffff8880a71ac010 RBP: ffff8880a71ac000 R08: ffff888091274000 R09: ffffed1007444955 R10: ffff88803a224aa3 R11: ffffed1007444954 R12: 0000000000000000 R13: ffff8880a0159200 R14: ffffc900185dfea0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ae600000(0063) knlGS:00000000f5d41b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 0000000008178000 CR3: 0000000056a63000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: qrtr_tun_write_iter+0xf5/0x180 net/qrtr/tun.c:92 call_write_iter include/linux/fs.h:1917 [inline] new_sync_write+0x426/0x650 fs/read_write.c:484 __vfs_write+0xc9/0x100 fs/read_write.c:497 vfs_write+0x268/0x5d0 fs/read_write.c:559 ksys_write+0x12d/0x250 fs/read_write.c:612 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x270/0xe90 arch/x86/entry/common.c:396 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 Modules linked in: ---[ end trace d4884e2d28c16d42 ]--- RIP: 0010:qrtr_endpoint_post+0x92/0xfa0 net/qrtr/qrtr.c:440 Code: 44 89 e6 e8 80 27 4e fe 48 85 c0 48 89 c5 0f 84 57 0e 00 00 e8 4f 7a 9e f9 48 89 da 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <0f> b6 04 02 48 89 da 83 e2 07 38 d0 7f 08 84 c0 0f 85 f7 0c 00 00 RSP: 0018:ffffc900185dfc38 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000010 RCX: ffffc900022c1000 RDX: 0000000000000002 RSI: ffffffff87d55471 RDI: ffff8880a71ac010 RBP: ffff8880a71ac000 R08: ffff888091274000 R09: ffffed1007444955 R10: ffff88803a224aa3 R11: ffffed1007444954 R12: 0000000000000000 R13: ffff8880a0159200 R14: ffffc900185dfea0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ae600000(0063) knlGS:00000000f5d41b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000080675b0 CR3: 0000000056a63000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400