scsi: aacraid: Prevent crash in case of free interrupt during scsi EH path
As part of the scsi EH path, aacraid performs a reinitialization of the
adapter, which encompass freeing resources and IRQs, NULLifying lots of
pointers, and then initialize it all over again. We've identified a
problem during the free IRQ portion of this path if CONFIG_DEBUG_SHIRQ
is enabled on kernel config file.
Happens that, in case this flag was set, right after free_irq()
effectively clears the interrupt, it checks if it was requested as
IRQF_SHARED. In positive case, it performs another call to the IRQ
handler on driver. Problem is: since aacraid currently free some
resources *before* freeing the IRQ, once free_irq() path calls the
handler again (due to CONFIG_DEBUG_SHIRQ), aacraid crashes due to NULL
pointer dereference with the following trace:
This patch prevents the crash by changing the order of the
deinitialization in this path of aacraid: first we clear the IRQ, then
we free other resources. No functional change intended.
Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com> Reviewed-by: Raghava Aditya Renukunta <RaghavaAditya.Renukunta@microsemi.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>