| Message ID | 20231030090924.2873408-1-islituo@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] scsi: message: fusion: Fix a possible data race in mpt_ioc_reset() | expand |
diff --git a/drivers/message/fusion/mptbase.c b/drivers/message/fusion/mptbase.c index 4bf669c55649..6c67eec9ab85 100644 --- a/drivers/message/fusion/mptbase.c +++ b/drivers/message/fusion/mptbase.c @@ -6563,7 +6563,7 @@ mpt_ioc_reset(MPT_ADAPTER *ioc, int reset_phase) { switch (reset_phase) { case MPT_IOC_SETUP_RESET: - ioc->taskmgmt_quiesce_io = 1; + WRITE_ONCE(ioc->taskmgmt_quiesce_io, 1); dtmprintk(ioc, printk(MYIOC_s_DEBUG_FMT "%s: MPT_IOC_SETUP_RESET\n", ioc->name, __func__)); break;
The variable ioc->taskmgmt_quiesce_io is often protected by the lock ioc->taskmgmt_lock when is accessed. Here is an example in mpt_SoftResetHandler(): spin_lock_irqsave(&ioc->taskmgmt_lock, flags); ... ioc->taskmgmt_quiesce_io = 0; ... spin_unlock_irqrestore(&ioc->taskmgmt_lock, flags); However, ioc->taskmgmt_quiesce_io is set to 1 without holding the lock ioc->taskmgmt_lock in mpt_ioc_reset(), which can cause possible data races: case MPT_IOC_SETUP_RESET: ioc->taskmgmt_quiesce_io = 1; To fix this possible data race, WRITE_ONCE() is used to access the variable ioc->taskmgmt_lock. Reported-by: BassCheck <bass@buaa.edu.cn> Signed-off-by: Tuo Li <islituo@gmail.com> --- v2: * Replace lock operations with a WRITE_ONCE to avoid possible data races. Thank Bart Van Assche for helpful advice. --- drivers/message/fusion/mptbase.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)