Potential race condition in drivers/ata/sata_mv.ko

[Pavel Andrianov]

Hi!

In drivers/ata/sata_mv.ko function mv_set_main_irq_mask is called 
several times. Twice with a spinlock, twice from init function and once 
without any protection. The call without protection rises to several 
handlers from ata_port_operations. The structure with the 
ata_port_operations is included into a structure 'host' in 
mv_platform_probe and in mv_pci_init_one. At the end of these functions 
ata_host operations are activated together with interrupt handler. The 
conclusion is: interrupt handler may be executed in parallel with 
handlers from ata_port_operations, or, more formally, it may interrupt 
its execution.

In mv_set_main_irq_mask and in interrupt handler mv_interrupt the 
interrupt mask is modified, but, as I said, handlers from 
ata_port_operations do not acquire any lock. Thus, the interrupt mask 
may be set incorrectly if the are two conflicting modifications.


--
Pavel Andrianov
Linux Verification Center, ISPRAS
web: http://linuxtesting.org
e-mail: andrianov@xxxxxxxxx