On 9/2/21 12:28 PM, syzbot wrote: > Hello, > > syzbot has tested the proposed patch but the reproducer is still triggering an issue: > general protection fault in io_ring_ctx_wait_and_kill > > general protection fault, probably for non-canonical address 0xdffffc0000000016: 0000 [#1] PREEMPT SMP KASAN > KASAN: null-ptr-deref in range [0x00000000000000b0-0x00000000000000b7] > CPU: 0 PID: 10163 Comm: syz-executor.2 Not tainted 5.14.0-rc7-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:io_ring_ctx_wait_and_kill+0x24d/0x450 fs/io_uring.c:9180 > Code: ff 48 89 df e8 c4 fb ff ff e8 6f a8 94 ff 48 8b 04 24 48 8d b8 b0 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 d3 01 00 00 48 8b 04 24 48 8b a8 b0 00 00 00 48 > RSP: 0018:ffffc9000a8b7a60 EFLAGS: 00010202 > RAX: dffffc0000000000 RBX: ffff888046aa6000 RCX: 0000000000000000 > RDX: 0000000000000016 RSI: ffffffff81e10061 RDI: 00000000000000b0 > RBP: 0000000000000000 R08: 0000000000000000 R09: ffff888046aa6643 > R10: ffffffff81e1004b R11: 0000000000000000 R12: ffff888046aa63f8 > R13: ffffc9000a8b7a90 R14: ffff8881453f4000 R15: ffff888046aa6040 > FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000561b3ede9400 CR3: 000000000b68e000 CR4: 00000000001506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > io_uring_release+0x3e/0x50 fs/io_uring.c:9198 > __fput+0x288/0x920 fs/file_table.c:280 > task_work_run+0xdd/0x1a0 kernel/task_work.c:164 > exit_task_work include/linux/task_work.h:32 [inline] > do_exit+0xbae/0x2a30 kernel/exit.c:825 > do_group_exit+0x125/0x310 kernel/exit.c:922 > get_signal+0x47f/0x2160 kernel/signal.c:2808 > arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865 > handle_signal_work kernel/entry/common.c:148 [inline] > exit_to_user_mode_loop kernel/entry/common.c:172 [inline] > exit_to_user_mode_prepare+0x17d/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: 0033:0x4665f9 > Code: Unable to access opcode bytes at RIP 0x4665cf. > RSP: 002b:00007faa595bc218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca > RAX: fffffffffffffe00 RBX: 000000000056c040 RCX: 00000000004665f9 > RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000056c040 > RBP: 000000000056c038 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c044 > R13: 00007fff98399dff R14: 00007faa595bc300 R15: 0000000000022000 > Modules linked in: > ---[ end trace 641488e48828d1de ]--- > RIP: 0010:io_ring_ctx_wait_and_kill+0x24d/0x450 fs/io_uring.c:9180 > Code: ff 48 89 df e8 c4 fb ff ff e8 6f a8 94 ff 48 8b 04 24 48 8d b8 b0 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 d3 01 00 00 48 8b 04 24 48 8b a8 b0 00 00 00 48 > RSP: 0018:ffffc9000a8b7a60 EFLAGS: 00010202 > RAX: dffffc0000000000 RBX: ffff888046aa6000 RCX: 0000000000000000 > RDX: 0000000000000016 RSI: ffffffff81e10061 RDI: 00000000000000b0 > RBP: 0000000000000000 R08: 0000000000000000 R09: ffff888046aa6643 > R10: ffffffff81e1004b R11: 0000000000000000 R12: ffff888046aa63f8 > R13: ffffc9000a8b7a90 R14: ffff8881453f4000 R15: ffff888046aa6040 > FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000561b3ede9400 CR3: 000000003cbf0000 CR4: 00000000001506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > ---------------- > Code disassembly (best guess), 1 bytes skipped: > 0: 48 89 df mov %rbx,%rdi > 3: e8 c4 fb ff ff callq 0xfffffbcc > 8: e8 6f a8 94 ff callq 0xff94a87c > d: 48 8b 04 24 mov (%rsp),%rax > 11: 48 8d b8 b0 00 00 00 lea 0xb0(%rax),%rdi > 18: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax > 1f: fc ff df > 22: 48 89 fa mov %rdi,%rdx > 25: 48 c1 ea 03 shr $0x3,%rdx > * 29: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction > 2d: 0f 85 d3 01 00 00 jne 0x206 > 33: 48 8b 04 24 mov (%rsp),%rax > 37: 48 8b a8 b0 00 00 00 mov 0xb0(%rax),%rbp > 3e: 48 rex.W That's unrelated, but probably my fault. Let's rerun: #syz test git://git.kernel.dk/linux-block for-5.15/io_uring -- Jens Axboe
