[SCSI] qla2xxx: Correct use-after-free oops seen during EH-abort.

Hold a reference to the srb (sp) while aborting an I/O -- as the
I/O can/will complete from within the interrupt-context.

Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
This commit is contained in:
Giridhar Malavali 2010-05-28 15:08:18 -07:00 committed by James Bottomley
parent 7e2b895b93
commit 083a469db4
2 changed files with 31 additions and 1 deletions

View File

@ -202,6 +202,7 @@ struct sd_dif_tuple {
* SCSI Request Block
*/
typedef struct srb {
atomic_t ref_count;
struct fc_port *fcport;
uint32_t handle;

View File

@ -517,6 +517,7 @@ qla2x00_get_new_sp(scsi_qla_host_t *vha, fc_port_t *fcport,
if (!sp)
return sp;
atomic_set(&sp->ref_count, 1);
sp->fcport = fcport;
sp->cmd = cmd;
sp->flags = 0;
@ -797,6 +798,12 @@ qla2x00_wait_for_loop_ready(scsi_qla_host_t *vha)
return (return_status);
}
static void
sp_get(struct srb *sp)
{
atomic_inc(&sp->ref_count);
}
/**************************************************************************
* qla2xxx_eh_abort
*
@ -825,6 +832,7 @@ qla2xxx_eh_abort(struct scsi_cmnd *cmd)
struct qla_hw_data *ha = vha->hw;
struct req_que *req = vha->req;
srb_t *spt;
int got_ref = 0;
fc_block_scsi_eh(cmd);
@ -856,6 +864,10 @@ qla2xxx_eh_abort(struct scsi_cmnd *cmd)
DEBUG2(printk("%s(%ld): aborting sp %p from RISC."
" pid=%ld.\n", __func__, vha->host_no, sp, serial));
/* Get a reference to the sp and drop the lock.*/
sp_get(sp);
got_ref++;
spin_unlock_irqrestore(&ha->hardware_lock, flags);
if (ha->isp_ops->abort_command(sp)) {
DEBUG2(printk("%s(%ld): abort_command "
@ -881,6 +893,9 @@ qla2xxx_eh_abort(struct scsi_cmnd *cmd)
}
}
if (got_ref)
qla2x00_sp_compl(ha, sp);
qla_printk(KERN_INFO, ha,
"scsi(%ld:%d:%d): Abort command issued -- %d %lx %x.\n",
vha->host_no, id, lun, wait, serial, ret);
@ -3468,7 +3483,7 @@ qla2x00_sp_free_dma(srb_t *sp)
}
void
qla2x00_sp_compl(struct qla_hw_data *ha, srb_t *sp)
qla2x00_sp_final_compl(struct qla_hw_data *ha, srb_t *sp)
{
struct scsi_cmnd *cmd = sp->cmd;
@ -3489,6 +3504,20 @@ qla2x00_sp_compl(struct qla_hw_data *ha, srb_t *sp)
cmd->scsi_done(cmd);
}
void
qla2x00_sp_compl(struct qla_hw_data *ha, srb_t *sp)
{
if (atomic_read(&sp->ref_count) == 0) {
DEBUG2(qla_printk(KERN_WARNING, ha,
"SP reference-count to ZERO -- sp=%p\n", sp));
DEBUG2(BUG());
return;
}
if (!atomic_dec_and_test(&sp->ref_count))
return;
qla2x00_sp_final_compl(ha, sp);
}
/**************************************************************************
* qla2x00_timer
*