[SCSI] libfc: Fix panic in fc_exch_recv
[SCSI] libfc: Fix panic in fc_exch_recv

Adding and removing the host into the zone causes this panic.

BUG: unable to handle kernel NULL pointer dereference at 00000000000000a0
IP: [<ffffffffa0491707>] fc_exch_recv+0xc57/0xe70 [libfc]
Call Trace:
[<ffffffffa050e04b>] bnx2fc_l2_rcv_thread+0x37b/0x430 [bnx2fc]
[<ffffffffa050dcd0>] ? bnx2fc_l2_rcv_thread+0x0/0x430 [bnx2fc]
[<ffffffff81090886>] kthread+0x96/0xa0
[<ffffffff8100c14a>] child_rip+0xa/0x20
[<ffffffff810907f0>] ? kthread+0x0/0xa0
[<ffffffff8100c140>] ? child_rip+0x0/0x20

During fc_exch_reset, the active exchanges are aborted and the exch is deleted.
As part of processing ABTS response, due to 'ep' being NULL, any access to ep in
fc_exch_recv_bls() causes this panic. Fixed to access 'ep' only if non-NULL.

Reviewed-by: Neerav Parikh <2a62f5509a5b60da1b5eb2008a8bcd0511123295@intel.com>
Signed-off-by: Bhanu Prakash Gollapudi <f19e710d7b7197dcf4c87db0713fbd82b9569382@broadcom.com>
Signed-off-by: Robert Love <ae32029cc3b561e3768d1db8669e99f5bdf25e4b@intel.com>
Signed-off-by: James Bottomley <1acebbdca565c7b6b638bdc23b58b5610d1a56b8@Parallels.com>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs