From 028b39e314dd8b4ab8d3ac401285db40ab1f39d8 Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bart.vanassche@sandisk.com>
Date: Tue, 28 Jun 2016 16:36:46 +0200
Subject: [PATCH] dm ioctl: Simplify parameter buffer management code
Merge the two DM_PARAMS_[KV]MALLOC flags into a single flag.
Doing so avoids the crashes seen with previous attempts to consolidate
buffer management to use kvfree() without first flagging that memory had
actually been allocated.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
---
drivers/md/dm-ioctl.c | 18 ++++++------------
1 file changed, 6 insertions(+), 12 deletions(-)
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index b59e34595ad8..96df89a31f42 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1670,8 +1670,7 @@ static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
return r;
}
-#define DM_PARAMS_KMALLOC 0x0001 /* Params alloced with kmalloc */
-#define DM_PARAMS_VMALLOC 0x0002 /* Params alloced with vmalloc */
+#define DM_PARAMS_MALLOC 0x0001 /* Params allocated with kvmalloc() */
#define DM_WIPE_BUFFER 0x0010 /* Wipe input buffer before returning from ioctl */
static void free_params(struct dm_ioctl *param, size_t param_size, int param_flags)
@@ -1679,10 +1678,8 @@ static void free_params(struct dm_ioctl *param, size_t param_size, int param_fla
if (param_flags & DM_WIPE_BUFFER)
memset(param, 0, param_size);
- if (param_flags & DM_PARAMS_KMALLOC)
- kfree(param);
- if (param_flags & DM_PARAMS_VMALLOC)
- vfree(param);
+ if (param_flags & DM_PARAMS_MALLOC)
+ kvfree(param);
}
static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kernel,
@@ -1714,19 +1711,14 @@ static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kern
* Use kmalloc() rather than vmalloc() when we can.
*/
dmi = NULL;
- if (param_kernel->data_size <= KMALLOC_MAX_SIZE) {
+ if (param_kernel->data_size <= KMALLOC_MAX_SIZE)
dmi = kmalloc(param_kernel->data_size, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN);
- if (dmi)
- *param_flags |= DM_PARAMS_KMALLOC;
- }
if (!dmi) {
unsigned noio_flag;
noio_flag = memalloc_noio_save();
dmi = __vmalloc(param_kernel->data_size, GFP_NOIO | __GFP_HIGH | __GFP_HIGHMEM, PAGE_KERNEL);
memalloc_noio_restore(noio_flag);
- if (dmi)
- *param_flags |= DM_PARAMS_VMALLOC;
}
if (!dmi) {
@@ -1735,6 +1727,8 @@ static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kern
return -ENOMEM;
}
+ *param_flags |= DM_PARAMS_MALLOC;
+
if (copy_from_user(dmi, user, param_kernel->data_size))
goto bad;
--
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