Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 1 UID: 0 PID: 17129 Comm: syz.5.2457 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:_compound_head include/linux/page-flags.h:284 [inline] RIP: 0010:io_check_coalesce_buffer+0x354/0xb60 io_uring/rsrc.c:746 Code: f7 e8 30 5f 63 fd 4c 89 74 24 28 48 8b 44 24 18 4c 8b 74 d8 08 49 8d 6e 08 48 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 ef e8 fe 5e 63 fd 48 8b 6d 00 48 89 ee 48 RSP: 0018:ffffc9000b637a38 EFLAGS: 00010202 RAX: 0000000000000001 RBX: 00000000000001ff RCX: dffffc0000000000 RDX: ffffc90014114000 RSI: 0000000000006c32 RDI: 0000000000006c33 RBP: 0000000000000008 R08: ffffea0001300007 R09: 1ffffd4000260000 R10: dffffc0000000000 R11: fffff94000260001 R12: ffff888057a50ff8 R13: 0000000000000200 R14: 0000000000000000 R15: ffffea0001300000 FS: 00007fdc885ba6c0(0000) GS:ffff888125af9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3ace19 CR3: 0000000028bbc000 CR4: 00000000003526f0 Call Trace: io_sqe_buffer_register+0x1ef/0x20a0 io_uring/rsrc.c:807 io_sqe_buffers_register+0x3b9/0x8e0 io_uring/rsrc.c:913 __io_uring_register io_uring/register.c:657 [inline] __do_sys_io_uring_register io_uring/register.c:926 [inline] __se_sys_io_uring_register+0xb85/0x11b0 io_uring/register.c:903 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdc8778ebe9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fdc885ba038 EFLAGS: 00000246 ORIG_RAX: 00000000000001ab RAX: ffffffffffffffda RBX: 00007fdc879c6360 RCX: 00007fdc8778ebe9 RDX: 00002000000002c0 RSI: 0000000000000000 RDI: 0000000000000007 RBP: 00007fdc87811e19 R08: 0000000000000000 R09: 0000000000000000 R10: 100000000000011a R11: 0000000000000246 R12: 0000000000000000 R13: 00007fdc879c63f8 R14: 00007fdc879c6360 R15: 00007fffa87d7168 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:_compound_head include/linux/page-flags.h:284 [inline] RIP: 0010:io_check_coalesce_buffer+0x354/0xb60 io_uring/rsrc.c:746 Code: f7 e8 30 5f 63 fd 4c 89 74 24 28 48 8b 44 24 18 4c 8b 74 d8 08 49 8d 6e 08 48 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 ef e8 fe 5e 63 fd 48 8b 6d 00 48 89 ee 48 RSP: 0018:ffffc9000b637a38 EFLAGS: 00010202 RAX: 0000000000000001 RBX: 00000000000001ff RCX: dffffc0000000000 RDX: ffffc90014114000 RSI: 0000000000006c32 RDI: 0000000000006c33 RBP: 0000000000000008 R08: ffffea0001300007 R09: 1ffffd4000260000 R10: dffffc0000000000 R11: fffff94000260001 R12: ffff888057a50ff8 R13: 0000000000000200 R14: 0000000000000000 R15: ffffea0001300000 FS: 00007fdc885ba6c0(0000) GS:ffff888125af9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3cc0cf56c0 CR3: 0000000028bbc000 CR4: 00000000003526f0 ---------------- Code disassembly (best guess): 0: f7 e8 imul %eax 2: 30 5f 63 xor %bl,0x63(%rdi) 5: fd std 6: 4c 89 74 24 28 mov %r14,0x28(%rsp) b: 48 8b 44 24 18 mov 0x18(%rsp),%rax 10: 4c 8b 74 d8 08 mov 0x8(%rax,%rbx,8),%r14 15: 49 8d 6e 08 lea 0x8(%r14),%rbp 19: 48 89 e8 mov %rbp,%rax 1c: 48 c1 e8 03 shr $0x3,%rax 20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 27: fc ff df * 2a: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction 2e: 74 08 je 0x38 30: 48 89 ef mov %rbp,%rdi 33: e8 fe 5e 63 fd call 0xfd635f36 38: 48 8b 6d 00 mov 0x0(%rbp),%rbp 3c: 48 89 ee mov %rbp,%rsi 3f: 48 rex.W