On 4/13/19 2:26 AM, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 8ee15f32 Merge tag 'dma-mapping-5.1-1' of git://git.infrad.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=146b7cd3200000 > kernel config: https://syzkaller.appspot.com/x/.config?x=4fb64439e07a1ec0 > dashboard link: https://syzkaller.appspot.com/bug?extid=cd714a07c6de2bc34293 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15d8b397200000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10b62ab7200000 > > The bug was bisected to: > > commit 6c271ce2f1d572f7fa225700a13cfe7ced492434 > Author: Jens Axboe <axboe@xxxxxxxxx> > Date: Thu Jan 10 18:22:30 2019 +0000 > > io_uring: add submission polling > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=170a286b200000 > final crash: https://syzkaller.appspot.com/x/report.txt?x=148a286b200000 > console output: https://syzkaller.appspot.com/x/log.txt?x=108a286b200000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+cd714a07c6de2bc34293@xxxxxxxxxxxxxxxxxxxxxxxxx > Fixes: 6c271ce2f1d5 ("io_uring: add submission polling") > > WARNING: CPU: 1 PID: 7600 at include/linux/cpumask.h:121 cpu_max_bits_warn > include/linux/cpumask.h:121 [inline] > WARNING: CPU: 1 PID: 7600 at include/linux/cpumask.h:121 cpumask_check > include/linux/cpumask.h:128 [inline] > WARNING: CPU: 1 PID: 7600 at include/linux/cpumask.h:121 cpumask_test_cpu > include/linux/cpumask.h:344 [inline] > WARNING: CPU: 1 PID: 7600 at include/linux/cpumask.h:121 > io_sq_offload_start fs/io_uring.c:2244 [inline] > WARNING: CPU: 1 PID: 7600 at include/linux/cpumask.h:121 io_uring_create > fs/io_uring.c:2851 [inline] > WARNING: CPU: 1 PID: 7600 at include/linux/cpumask.h:121 > io_uring_setup+0x13b2/0x1990 fs/io_uring.c:2903 > Kernel panic - not syncing: panic_on_warn set ... > CPU: 1 PID: 7600 Comm: syz-executor594 Not tainted 5.1.0-rc4+ #65 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x172/0x1f0 lib/dump_stack.c:113 > panic+0x2cb/0x65c kernel/panic.c:214 > __warn.cold+0x20/0x45 kernel/panic.c:571 > report_bug+0x263/0x2b0 lib/bug.c:186 > fixup_bug arch/x86/kernel/traps.c:179 [inline] > fixup_bug arch/x86/kernel/traps.c:174 [inline] > do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272 > do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291 > invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973 > RIP: 0010:cpu_max_bits_warn include/linux/cpumask.h:121 [inline] > RIP: 0010:cpumask_check include/linux/cpumask.h:128 [inline] > RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:344 [inline] > RIP: 0010:io_sq_offload_start fs/io_uring.c:2244 [inline] > RIP: 0010:io_uring_create fs/io_uring.c:2851 [inline] > RIP: 0010:io_uring_setup+0x13b2/0x1990 fs/io_uring.c:2903 > Code: 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 80 3c 02 00 0f 84 18 fe ff > ff 48 89 df e8 e8 80 e0 ff e9 0b fe ff ff e8 2e 79 a8 ff <0f> 0b e9 db f8 > ff ff e8 22 79 a8 ff 49 8d 9c 24 88 00 00 00 48 b8 > RSP: 0018:ffff8880a8eb7dc0 EFLAGS: 00010293 > RAX: ffff88808cdd8700 RBX: 0000000000000400 RCX: ffffffff81c80eab > RDX: 0000000000000000 RSI: ffffffff81c815d2 RDI: 0000000000000005 > RBP: ffff8880a8eb7ef0 R08: ffff88808cdd8700 R09: ffffed1011c75244 > R10: ffffed1011c75243 R11: ffff88808e3a921f R12: ffff88808d34a480 > R13: ffff8880a8eb7ec8 R14: ffff88808d34a4c0 R15: ffff88808d34a4d4 > __do_sys_io_uring_setup fs/io_uring.c:2916 [inline] > __se_sys_io_uring_setup fs/io_uring.c:2913 [inline] > __x64_sys_io_uring_setup+0x54/0x80 fs/io_uring.c:2913 > do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x440239 > Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007fff32156718 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9 > RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440239 > RDX: 0000000000400b60 RSI: 0000000020000200 RDI: 0000000000000c9f > RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 > R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000401ac0 > R13: 0000000000401b50 R14: 0000000000000000 R15: 0000000000000000 > Kernel Offset: disabled > Rebooting in 86400 seconds.. Thanks for the report, below should fix it. -- Jens Axboe