[PATCH] lsilogic mpt fusion: mptctl: Fixed race condition around mptctl_id variable using mutexes

From: Mark Balantzyan
Date: Wed Aug 14 2019 - 16:48:37 EST


Certain functions in the driver, such as mptctl_do_fw_download() and
mptctl_do_mpt_command(), rely on the instance of mptctl_id, which does the
id-ing. There is race condition possible when these functions operate in
concurrency. Via, mutexes, the functions are mutually signalled to cooperate.

Signed-off-by: Mark Balantzyan <mbalant3@xxxxxxxxx>

---
drivers/message/fusion/mptctl.c | 39 ++++++++++++++++++++++++++-------
1 file changed, 31 insertions(+), 8 deletions(-)

diff --git a/drivers/message/fusion/mptctl.c b/drivers/message/fusion/mptctl.c
index 4470630d..f0b49a85 100644
--- a/drivers/message/fusion/mptctl.c
+++ b/drivers/message/fusion/mptctl.c
@@ -816,12 +816,15 @@ mptctl_do_fw_download(int ioc, char __user *ufwbuf, size_t fwlen)

/* Valid device. Get a message frame and construct the FW download message.
*/
+ mutex_lock(&mpctl_mutex);
if ((mf = mpt_get_msg_frame(mptctl_id, iocp)) == NULL)
+ mutex_unlock(&mpctl_mutex);
return -EAGAIN;
}
-
+ mutex_lock(&mpctl_mutex);
dctlprintk(iocp, printk(MYIOC_s_DEBUG_FMT
"mptctl_do_fwdl called. mptctl_id = %xh.\n", iocp->name, mptctl_id));
+ mutex_unlock(&mpctl_mutex);
dctlprintk(iocp, printk(MYIOC_s_DEBUG_FMT "DbG: kfwdl.bufp = %p\n",
iocp->name, ufwbuf));
dctlprintk(iocp, printk(MYIOC_s_DEBUG_FMT "DbG: kfwdl.fwlen = %d\n",
@@ -943,7 +946,9 @@ mptctl_do_fw_download(int ioc, char __user *ufwbuf, size_t fwlen)
ReplyMsg = NULL;
SET_MGMT_MSG_CONTEXT(iocp->ioctl_cmds.msg_context, dlmsg->MsgContext);
INITIALIZE_MGMT_STATUS(iocp->ioctl_cmds.status)
+ mutex_lock(&mpctl_mutex);
mpt_put_msg_frame(mptctl_id, iocp, mf);
+ mutex_lock(&mpctl_mutex);

/* Now wait for the command to complete */
retry_wait:
@@ -1889,7 +1894,9 @@ mptctl_do_mpt_command (struct mpt_ioctl_command karg, void __user *mfPtr)

/* Get a free request frame and save the message context.
*/
+ mutex_lock(&mpctl_mutex);
if ((mf = mpt_get_msg_frame(mptctl_id, ioc)) == NULL)
+ mutex_unlock(&mpctl_mutex);
return -EAGAIN;

hdr = (MPIHeader_t *) mf;
@@ -2271,11 +2278,14 @@ mptctl_do_mpt_command (struct mpt_ioctl_command karg, void __user *mfPtr)
DBG_DUMP_TM_REQUEST_FRAME(ioc, (u32 *)mf);

if ((ioc->facts.IOCCapabilities & MPI_IOCFACTS_CAPABILITY_HIGH_PRI_Q) &&
- (ioc->facts.MsgVersion >= MPI_VERSION_01_05))
+ (ioc->facts.MsgVersion >= MPI_VERSION_01_05)) {
+ mutex_lock(&mpctl_mutex);
mpt_put_msg_frame_hi_pri(mptctl_id, ioc, mf);
- else {
- rc =mpt_send_handshake_request(mptctl_id, ioc,
- sizeof(SCSITaskMgmt_t), (u32*)mf, CAN_SLEEP);
+ mutex_unlock(&mpctl_mutex);
+ } else {
+ mutex_lock(&mpctl_mutex);
+ rc = mpt_send_handshake_request(mptctl_id, ioc, sizeof(SCSITaskMgmt_t), (u32 *)mf, CAN_SLEEP);
+ mutex_unlock(&mpctl_mutex);
if (rc != 0) {
dfailprintk(ioc, printk(MYIOC_s_ERR_FMT
"send_handshake FAILED! (ioc %p, mf %p)\n",
@@ -2287,8 +2297,11 @@ mptctl_do_mpt_command (struct mpt_ioctl_command karg, void __user *mfPtr)
}
}

- } else
+ } else {
+ mutex_lock(&mpctl_mutex);
mpt_put_msg_frame(mptctl_id, ioc, mf);
+ mutex_unlock(&mpctl_mutex);
+ }

/* Now wait for the command to complete */
timeout = (karg.timeout > 0) ? karg.timeout : MPT_IOCTL_DEFAULT_TIMEOUT;
@@ -2563,7 +2576,9 @@ mptctl_hp_hostinfo(unsigned long arg, unsigned int data_size)
/*
* Gather ISTWI(Industry Standard Two Wire Interface) Data
*/
+ mutex_lock(&mpctl_mutex);
if ((mf = mpt_get_msg_frame(mptctl_id, ioc)) == NULL) {
+ mutex_unlock(&mpctl_mutex);
dfailprintk(ioc, printk(MYIOC_s_WARN_FMT
"%s, no msg frames!!\n", ioc->name, __func__));
goto out;
@@ -2593,7 +2608,9 @@ mptctl_hp_hostinfo(unsigned long arg, unsigned int data_size)
SET_MGMT_MSG_CONTEXT(ioc->ioctl_cmds.msg_context,
IstwiRWRequest->MsgContext);
INITIALIZE_MGMT_STATUS(ioc->ioctl_cmds.status)
+ mutex_lock(&mpctl_mutex);
mpt_put_msg_frame(mptctl_id, ioc, mf);
+ mutex_unlock(&mpctl_mutex);

retry_wait:
timeleft = wait_for_completion_timeout(&ioc->ioctl_cmds.done,
@@ -3010,9 +3027,11 @@ static int __init mptctl_init(void)
* Install our handler
*/
++where;
+ mutex_lock(&mpctl_mutex);
mptctl_id = mpt_register(mptctl_reply, MPTCTL_DRIVER,
"mptctl_reply");
if (!mptctl_id || mptctl_id >= MPT_MAX_PROTOCOL_DRIVERS) {
+ mutex_unlock(&mpctl_mutex);
printk(KERN_ERR MYNAM ": ERROR: Failed to register with Fusion MPT base driver\n");
misc_deregister(&mptctl_miscdev);
err = -EBUSY;
@@ -3022,13 +3041,14 @@ static int __init mptctl_init(void)
mptctl_taskmgmt_id = mpt_register(mptctl_taskmgmt_reply, MPTCTL_DRIVER,
"mptctl_taskmgmt_reply");
if (!mptctl_taskmgmt_id || mptctl_taskmgmt_id >= MPT_MAX_PROTOCOL_DRIVERS) {
+ mutex_unlock(&mpctl_mutex);
printk(KERN_ERR MYNAM ": ERROR: Failed to register with Fusion MPT base driver\n");
mpt_deregister(mptctl_id);
misc_deregister(&mptctl_miscdev);
err = -EBUSY;
goto out_fail;
}
-
+ mutex_unlock(&mpctl_mutex);
mpt_reset_register(mptctl_id, mptctl_ioc_reset);
mpt_event_register(mptctl_id, mptctl_event_process);

@@ -3044,13 +3064,14 @@ out_fail:
/*=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=*/
static void mptctl_exit(void)
{
+ mutex_lock(&mpctl_mutex);
misc_deregister(&mptctl_miscdev);
printk(KERN_INFO MYNAM ": Deregistered /dev/%s @ (major,minor=%d,%d)\n",
mptctl_miscdev.name, MISC_MAJOR, mptctl_miscdev.minor);

/* De-register event handler from base module */
mpt_event_deregister(mptctl_id);
-
+
/* De-register reset handler from base module */
mpt_reset_deregister(mptctl_id);

@@ -3058,6 +3079,8 @@ static void mptctl_exit(void)
mpt_deregister(mptctl_taskmgmt_id);
mpt_deregister(mptctl_id);

+ mutex_unlock(&mpctl_mutex);
+
mpt_device_driver_deregister(MPTCTL_DRIVER);

}
--
2.17.1