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 [off-list ref] 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