Re: [PATCHv2] iscsi-target: Don't use stack buffer for scatterlist

[Martin K. Petersen]

> Fedora got a bug report of a crash with iSCSI:
>
> kernel BUG at include/linux/scatterlist.h:143!
> ...
> RIP: 0010:iscsit_do_crypto_hash_buf+0x154/0x180 [iscsi_target_mod]
> ...
>  Call Trace:
>   ? iscsi_target_tx_thread+0x200/0x200 [iscsi_target_mod]
>   iscsit_get_rx_pdu+0x4cd/0xa90 [iscsi_target_mod]
>   ? native_sched_clock+0x3e/0xa0
>   ? iscsi_target_tx_thread+0x200/0x200 [iscsi_target_mod]
>   iscsi_target_rx_thread+0x81/0xf0 [iscsi_target_mod]
>   kthread+0x120/0x140
>   ? kthread_create_worker_on_cpu+0x70/0x70
>   ret_from_fork+0x3a/0x50
>
> This is a BUG_ON for using a stack buffer with a scatterlist.  There
> are two cases that trigger this bug. Switch to using a dynamically
> allocated buffer for one case and do not assign a NULL buffer in
> another case.

Mike: Please review. Thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering