general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 1 PID: 24167 Comm: syz-executor.5 Not tainted 5.8.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:qrtr_endpoint_post+0x8f/0x1110 net/qrtr/qrtr.c:440 Code: 44 89 ee ba 20 0a 00 00 e8 0e d9 4f fe 48 85 c0 0f 84 5c 02 00 00 49 89 c7 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <8a> 04 08 84 c0 0f 85 7d 09 00 00 4d 8d 77 28 41 0f b6 1c 24 48 89 RSP: 0018:ffffc90003e37d20 EFLAGS: 00010202 RAX: 0000000000000002 RBX: ffff8880a6515708 RCX: dffffc0000000000 RDX: ffffc90014104000 RSI: 000000000000008b RDI: ffff8880a949c738 RBP: ffff888050e1fc00 R08: ffffffff86642ecc R09: ffffed10092ada7d R10: ffffed10092ada7d R11: 0000000000000000 R12: 0000000000000010 R13: 0000000000000000 R14: ffffc90003e37dd8 R15: ffff8880a949c680 FS: 00007f1679e82700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000050e090 CR3: 00000000a135e000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: qrtr_tun_write_iter+0xc6/0x120 net/qrtr/tun.c:92 call_write_iter include/linux/fs.h:1907 [inline] new_sync_write fs/read_write.c:484 [inline] __vfs_write+0x52f/0x6e0 fs/read_write.c:497 vfs_write+0x274/0x580 fs/read_write.c:559 ksys_write+0x11b/0x220 fs/read_write.c:612 do_syscall_64+0x73/0xe0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45cb19 Code: Bad RIP value. RSP: 002b:00007f1679e81c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000050e080 RCX: 000000000045cb19 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000d2a R14: 00000000004cf851 R15: 00007f1679e826d4 Modules linked in: ---[ end trace 7de89b4d6891e811 ]--- RIP: 0010:qrtr_endpoint_post+0x8f/0x1110 net/qrtr/qrtr.c:440 Code: 44 89 ee ba 20 0a 00 00 e8 0e d9 4f fe 48 85 c0 0f 84 5c 02 00 00 49 89 c7 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <8a> 04 08 84 c0 0f 85 7d 09 00 00 4d 8d 77 28 41 0f b6 1c 24 48 89 RSP: 0018:ffffc90003e37d20 EFLAGS: 00010202 RAX: 0000000000000002 RBX: ffff8880a6515708 RCX: dffffc0000000000 RDX: ffffc90014104000 RSI: 000000000000008b RDI: ffff8880a949c738 RBP: ffff888050e1fc00 R08: ffffffff86642ecc R09: ffffed10092ada7d R10: ffffed10092ada7d R11: 0000000000000000 R12: 0000000000000010 R13: 0000000000000000 R14: ffffc90003e37dd8 R15: ffff8880a949c680 FS: 00007f1679e82700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd22927630 CR3: 00000000a135e000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400