syzbot has found a reproducer for the following issue on: HEAD commit: 93717cde744f Add linux-next specific files for 20210830 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=15200fad300000 kernel config: https://syzkaller.appspot.com/x/.config?x=c643ef5289990dd1 dashboard link: https://syzkaller.appspot.com/bug?extid=f9704d1878e290eddf73 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=111f5f9d300000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1651a415300000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+f9704d1878e290eddf73@xxxxxxxxxxxxxxxxxxxxxxxxx general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] CPU: 0 PID: 6548 Comm: syz-executor433 Not tainted 5.14.0-next-20210830-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:sock_from_file+0x20/0x90 net/socket.c:505 Code: f5 ff ff ff c3 0f 1f 44 00 00 41 54 53 48 89 fb e8 85 e9 62 fa 48 8d 7b 28 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 4f 45 31 e4 48 81 7b 28 80 f1 8a 8a 74 0c e8 58 e9 RSP: 0018:ffffc90002caf8e8 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000005 RSI: ffffffff8713203b RDI: 0000000000000028 RBP: ffff888019fc0780 R08: ffffffff899aee40 R09: ffffffff81e21978 R10: 0000000000000027 R11: 0000000000000009 R12: dffffc0000000000 R13: 1ffff110033f80f9 R14: 0000000000000003 R15: ffff888019fc0780 FS: 00000000013b5300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004ae0f0 CR3: 000000001d355000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: io_sendmsg+0x98/0x640 fs/io_uring.c:4681 io_issue_sqe+0x14de/0x6ba0 fs/io_uring.c:6578 __io_queue_sqe+0x90/0xb50 fs/io_uring.c:6864 io_req_task_submit+0xbf/0x1b0 fs/io_uring.c:2218 tctx_task_work+0x166/0x610 fs/io_uring.c:2143 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_signal include/linux/tracehook.h:212 [inline] handle_signal_work kernel/entry/common.c:146 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x256/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x43fd49 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd6347b9d8 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: 0000000000001000 RBX: 0000000000000003 RCX: 000000000043fd49 RDX: 0000000000000000 RSI: 000000000000688c RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004035d0 R13: 431bde82d7b634db R14: 00000000004ae018 R15: 0000000000400488 Modules linked in: ---[ end trace aa9bf60339277d03 ]--- RIP: 0010:sock_from_file+0x20/0x90 net/socket.c:505 Code: f5 ff ff ff c3 0f 1f 44 00 00 41 54 53 48 89 fb e8 85 e9 62 fa 48 8d 7b 28 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 4f 45 31 e4 48 81 7b 28 80 f1 8a 8a 74 0c e8 58 e9 RSP: 0018:ffffc90002caf8e8 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000005 RSI: ffffffff8713203b RDI: 0000000000000028 RBP: ffff888019fc0780 R08: ffffffff899aee40 R09: ffffffff81e21978 R10: 0000000000000027 R11: 0000000000000009 R12: dffffc0000000000 R13: 1ffff110033f80f9 R14: 0000000000000003 R15: ffff888019fc0780 FS: 00000000013b5300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2cc6f84000 CR3: 000000001d355000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess), 3 bytes skipped: 0: ff c3 inc %ebx 2: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 7: 41 54 push %r12 9: 53 push %rbx a: 48 89 fb mov %rdi,%rbx d: e8 85 e9 62 fa callq 0xfa62e997 12: 48 8d 7b 28 lea 0x28(%rbx),%rdi 16: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1d: fc ff df 20: 48 89 fa mov %rdi,%rdx 23: 48 c1 ea 03 shr $0x3,%rdx * 27: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction 2b: 75 4f jne 0x7c 2d: 45 31 e4 xor %r12d,%r12d 30: 48 81 7b 28 80 f1 8a cmpq $0xffffffff8a8af180,0x28(%rbx) 37: 8a 38: 74 0c je 0x46 3a: e8 .byte 0xe8 3b: 58 pop %rax 3c: e9 .byte 0xe9
