kernel panic while using get_random_bytes

[Temp Sha]

hi, can any one help me with this issue?  please let me know if this
is not correct form to ask this question?
thanks

On Mon, Oct 14, 2019 at 1:51 PM Temp Sha <temp.sha at gmail.com> wrote:
>
> hi,
>
> i use get_random_bytes() function for my randomness requirement in
> kernel version 4.14.142
> however is gives panic as soon as I call   get_random_bytes() in my module.
>
>
> Oct 10 07:20:18 BUG: unable to handle kernel paging request at 00007f5563ced000
> IP: chacha20_block+0x24d/0x280
> PGD 800000010f7f8067 P4D 800000010f7f8067 PUD 161316067 PMD 1015a8067 PTE 0
> Oops: 0002 [#1] PREEMPT SMP PTI
> Modules linked in: ipi_hsl(PO) mymod(PO) e1000 ipv6 ftdi_sio usbserial
> xt_tcpudp xt_mark iptable_nat nf_nat_ipv4 nf_conntrack_ipv4
> nf_defrag_ipv4 nf_nat xt_connlimit nf_conntrack iptable_filter
> ip_tables x_tables
> CPU: 0 PID: 1841 Comm: hexdump Tainted: P           O    4.14.142-ws-symbol #1
> Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
> task: ffff8881611da000 task.stack: ffffc900504c4000
> RIP: 0010:chacha20_block+0x24d/0x280
> RSP: 0018:ffffc900504c7c70 EFLAGS: 00010886
> RAX: 0000000000000000 RBX: 00000000a88c95b0 RCX: 00007f5563ced000
> RDX: ffff88810f79da00 RSI: 0000000015c4332e RDI: 000000007613f298
> RBP: ffffc900504c7d00 R08: 000000009d39d68d R09: 00000000bfbdb51f
> R10: 00000000ed798a26 R11: 0000000083c184dc R12: 0000000036fc61e0
> R13: 00000000f9004639 R14: 0000000042c0d351 R15: 000000008a6cef0f
> FS:  00007f5563cef700(0000) GS:ffff888167e00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f5563ced000 CR3: 000000016117c000 CR4: 00000000000006b0
> Call Trace:
>  _extract_crng+0x6d/0xc0
>  extract_crng+0x3a/0x40
>  _get_random_bytes+0x56/0x1c0
>  ? vprintk_func+0x3f/0xd0
>  ? printk+0x3e/0x46
>  get_random_bytes+0x2f/0x40
>  xyz_packets+0x1110/0x11e0 [mymod]
>  proc_reg_read+0x3d/0x60
>  __vfs_read+0x23/0x120
>  ? vm_mmap_pgoff+0x9d/0xd0
>  vfs_read+0x8e/0x110
>  SyS_read+0x48/0xc0
>  do_syscall_64+0x5c/0x260
>  entry_SYSCALL_64_after_hwframe+0x3d/0xa2
> RIP: 0033:0x7f55631f
>
>
> what could be the problem?
>
>
> thanks