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path: root/drivers/md/dm-ioctl.c
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Diffstat (limited to 'drivers/md/dm-ioctl.c')
-rw-r--r--drivers/md/dm-ioctl.c37
1 files changed, 24 insertions, 13 deletions
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 8756a6850431..e52676fa9832 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -477,9 +477,13 @@ static int remove_all(struct file *filp, struct dm_ioctl *param, size_t param_si
* Round up the ptr to an 8-byte boundary.
*/
#define ALIGN_MASK 7
+static inline size_t align_val(size_t val)
+{
+ return (val + ALIGN_MASK) & ~ALIGN_MASK;
+}
static inline void *align_ptr(void *ptr)
{
- return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK);
+ return (void *)align_val((size_t)ptr);
}
/*
@@ -505,7 +509,7 @@ static int list_devices(struct file *filp, struct dm_ioctl *param, size_t param_
struct hash_cell *hc;
size_t len, needed = 0;
struct gendisk *disk;
- struct dm_name_list *nl, *old_nl = NULL;
+ struct dm_name_list *orig_nl, *nl, *old_nl = NULL;
uint32_t *event_nr;
down_write(&_hash_lock);
@@ -516,17 +520,15 @@ static int list_devices(struct file *filp, struct dm_ioctl *param, size_t param_
*/
for (i = 0; i < NUM_BUCKETS; i++) {
list_for_each_entry (hc, _name_buckets + i, name_list) {
- needed += sizeof(struct dm_name_list);
- needed += strlen(hc->name) + 1;
- needed += ALIGN_MASK;
- needed += (sizeof(uint32_t) + ALIGN_MASK) & ~ALIGN_MASK;
+ needed += align_val(offsetof(struct dm_name_list, name) + strlen(hc->name) + 1);
+ needed += align_val(sizeof(uint32_t));
}
}
/*
* Grab our output buffer.
*/
- nl = get_result_buffer(param, param_size, &len);
+ nl = orig_nl = get_result_buffer(param, param_size, &len);
if (len < needed) {
param->flags |= DM_BUFFER_FULL_FLAG;
goto out;
@@ -549,11 +551,16 @@ static int list_devices(struct file *filp, struct dm_ioctl *param, size_t param_
strcpy(nl->name, hc->name);
old_nl = nl;
- event_nr = align_ptr(((void *) (nl + 1)) + strlen(hc->name) + 1);
+ event_nr = align_ptr(nl->name + strlen(hc->name) + 1);
*event_nr = dm_get_event_nr(hc->md);
nl = align_ptr(event_nr + 1);
}
}
+ /*
+ * If mismatch happens, security may be compromised due to buffer
+ * overflow, so it's better to crash.
+ */
+ BUG_ON((char *)nl - (char *)orig_nl != needed);
out:
up_write(&_hash_lock);
@@ -1621,7 +1628,8 @@ static int target_message(struct file *filp, struct dm_ioctl *param, size_t para
* which has a variable size, is not used by the function processing
* the ioctl.
*/
-#define IOCTL_FLAGS_NO_PARAMS 1
+#define IOCTL_FLAGS_NO_PARAMS 1
+#define IOCTL_FLAGS_ISSUE_GLOBAL_EVENT 2
/*-----------------------------------------------------------------
* Implementation of open/close/ioctl on the special char
@@ -1635,12 +1643,12 @@ static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags)
ioctl_fn fn;
} _ioctls[] = {
{DM_VERSION_CMD, 0, NULL}, /* version is dealt with elsewhere */
- {DM_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS, remove_all},
+ {DM_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, remove_all},
{DM_LIST_DEVICES_CMD, 0, list_devices},
- {DM_DEV_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS, dev_create},
- {DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS, dev_remove},
- {DM_DEV_RENAME_CMD, 0, dev_rename},
+ {DM_DEV_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_create},
+ {DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_remove},
+ {DM_DEV_RENAME_CMD, IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_rename},
{DM_DEV_SUSPEND_CMD, IOCTL_FLAGS_NO_PARAMS, dev_suspend},
{DM_DEV_STATUS_CMD, IOCTL_FLAGS_NO_PARAMS, dev_status},
{DM_DEV_WAIT_CMD, 0, dev_wait},
@@ -1869,6 +1877,9 @@ static int ctl_ioctl(struct file *file, uint command, struct dm_ioctl __user *us
unlikely(ioctl_flags & IOCTL_FLAGS_NO_PARAMS))
DMERR("ioctl %d tried to output some data but has IOCTL_FLAGS_NO_PARAMS set", cmd);
+ if (!r && ioctl_flags & IOCTL_FLAGS_ISSUE_GLOBAL_EVENT)
+ dm_issue_global_event();
+
/*
* Copy the results back to userland.
*/