Server crashed in fsf_set_rw() function due to third party module cdr.

Issue

• The system crashed with the following call traces in the kernel ring buffer :

[4224891.770622] BUG: unable to handle kernel paging request at ffffbc5a808100e0
[4224891.770628] IP: [<ffffffffc07e28bc>] fsf_set_rw+0xbc/0x110 [cdr]
[4224891.770634] PGD 46c5bd067 PUD 0 
[4224891.770637] Oops: 0000 [#1] SMP 
[...]
[4224891.770701]  [<ffffffffc07f0250>] fsf_hijack_inode+0x1e0/0xbe0 [cdr]
[4224891.770704]  [<ffffffffc07f2a46>] fsf_ops_aio_read+0x96/0xf0 [cdr]
[4224891.770710]  [<ffffffffa781e683>] do_sync_read+0x93/0xe0
[4224891.770713]  [<ffffffffc07e4bd9>] cdr_ops_read+0x39/0xb0 [cdr]
[4224891.770716]  [<ffffffffc07f88f9>] cxfs_ops_read+0x69/0x120 [cdr]
[4224891.770718]  [<ffffffffc07f2b1b>] fsf_ops_read+0x7b/0xe0 [cdr]
[4224891.770720]  [<ffffffffa781f0af>] vfs_read+0x9f/0x170
[4224891.770722]  [<ffffffffa781ff7f>] SyS_read+0x7f/0xf0
[4224891.770727]  [<ffffffffa7d2579b>] system_call_fastpath+0x22/0x27
[4224891.770728] Code: 48 89 c1 41 81 e0 f8 0f 00 00 4c 03 05 9e eb a5 e7 4c 01 c1 48 8b 39 48 f7 c7 9f ff ff ff 74 c0 40 f6 c7 80 74 29 48 85 c9 74 b5 <48> 8b 39 48 f7 c7 9f ff ff ff 74 a9 48 89 f8 0f 1f 40 00 a8 02 
[4224891.770746] RIP  [<ffffffffc07e28bc>] fsf_set_rw+0xbc/0x110 [cdr]
[4224891.770748]  RSP <ffff8d0bacb77c90>
[4224891.770749] CR2: ffffbc5a808100e0