Re: [PATCH] cxl: Fix error path on bad ioctl

[Frederic Barrat]

Le 06/06/2017 à 11:20, Michael Ellerman a écrit :
Frederic Barrat <fbar...@linux.vnet.ibm.com> writes:

Fix error path if we can't copy user structure on
CXL_IOCTL_START_WORK ioctl.

To be clear the error is that returning via the out label will unlock
cxl->status_mutex, which has not been locked.

Please spell it out for me :)

This should be:

   Fixes: 0712dc7e73e5 ("cxl: Fix issues when unmapping contexts")

Am I right?


That's correct. I'm about to send a v2 to address Vaibhav's comment and 
I'll fix the above as well.

Thanks,

  Fred



cheers

diff --git a/drivers/misc/cxl/file.c b/drivers/misc/cxl/file.c
index 17b433f1ce23..caa44adfa60e 100644
--- a/drivers/misc/cxl/file.c
+++ b/drivers/misc/cxl/file.c
@@ -160,10 +160,8 @@ static long afu_ioctl_start_work(struct cxl_context *ctx,
        /* Do this outside the status_mutex to avoid a circular dependency with
         * the locking in cxl_mmap_fault() */
        if (copy_from_user(&work, uwork,
-                          sizeof(struct cxl_ioctl_start_work))) {
-               rc = -EFAULT;
-               goto out;
-       }
+                          sizeof(struct cxl_ioctl_start_work)))
+               return -EFAULT;
  
  	mutex_lock(&ctx->status_mutex);
        if (ctx->status != OPENED) {
--
2.11.0