[PATCH 3.5 050/103] dm: fix truncated status strings
From: Luis Henriques
Date: Tue Dec 17 2013 - 13:32:28 EST
3.5.7.28 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Mikulas Patocka <mpatocka@xxxxxxxxxx>
commit fd7c092e711ebab55b2688d3859d95dfd0301f73 upstream.
Avoid returning a truncated table or status string instead of setting
the DM_BUFFER_FULL_FLAG when the last target of a table fills the
buffer.
When processing a table or status request, the function retrieve_status
calls ti->type->status. If ti->type->status returns non-zero,
retrieve_status assumes that the buffer overflowed and sets
DM_BUFFER_FULL_FLAG.
However, targets don't return non-zero values from their status method
on overflow. Most targets returns always zero.
If a buffer overflow happens in a target that is not the last in the
table, it gets noticed during the next iteration of the loop in
retrieve_status; but if a buffer overflow happens in the last target, it
goes unnoticed and erroneously truncated data is returned.
In the current code, the targets behave in the following way:
* dm-crypt returns -ENOMEM if there is not enough space to store the
key, but it returns 0 on all other overflows.
* dm-thin returns errors from the status method if a disk error happened.
This is incorrect because retrieve_status doesn't check the error
code, it assumes that all non-zero values mean buffer overflow.
* all the other targets always return 0.
This patch changes the ti->type->status function to return void (because
most targets don't use the return code). Overflow is detected in
retrieve_status: if the status method fills up the remaining space
completely, it is assumed that buffer overflow happened.
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Signed-off-by: Alasdair G Kergon <agk@xxxxxxxxxx>
Cc: Mikulas Patocka <mpatocka@xxxxxxxxxx>
[ luis: backported to 3.5: based on Mikulas backport to 3.4 ]
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
drivers/md/dm-crypt.c | 37 +++++-----------------
drivers/md/dm-delay.c | 6 ++--
drivers/md/dm-flakey.c | 5 ++-
drivers/md/dm-ioctl.c | 18 +++++++----
drivers/md/dm-linear.c | 5 ++-
drivers/md/dm-mpath.c | 6 ++--
drivers/md/dm-raid.c | 6 ++--
drivers/md/dm-raid1.c | 6 ++--
drivers/md/dm-snap.c | 12 +++----
drivers/md/dm-stripe.c | 5 ++-
drivers/md/dm-thin.c | 74 +++++++++++++++++++++++++++----------------
drivers/md/dm-verity.c | 6 ++--
include/linux/device-mapper.h | 4 +--
13 files changed, 87 insertions(+), 103 deletions(-)
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 3f06df5..535c3e2 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1262,20 +1262,6 @@ static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
return 0;
}
-/*
- * Encode key into its hex representation
- */
-static void crypt_encode_key(char *hex, u8 *key, unsigned int size)
-{
- unsigned int i;
-
- for (i = 0; i < size; i++) {
- sprintf(hex, "%02x", *key);
- hex += 2;
- key++;
- }
-}
-
static void crypt_free_tfms(struct crypt_config *cc, int cpu)
{
struct crypt_cpu *cpu_cc = per_cpu_ptr(cc->cpu, cpu);
@@ -1741,11 +1727,11 @@ static int crypt_map(struct dm_target *ti, struct bio *bio,
return DM_MAPIO_SUBMITTED;
}
-static int crypt_status(struct dm_target *ti, status_type_t type,
- char *result, unsigned int maxlen)
+static void crypt_status(struct dm_target *ti, status_type_t type,
+ char *result, unsigned int maxlen)
{
struct crypt_config *cc = ti->private;
- unsigned int sz = 0;
+ unsigned i, sz = 0;
switch (type) {
case STATUSTYPE_INFO:
@@ -1755,17 +1741,11 @@ static int crypt_status(struct dm_target *ti, status_type_t type,
case STATUSTYPE_TABLE:
DMEMIT("%s ", cc->cipher_string);
- if (cc->key_size > 0) {
- if ((maxlen - sz) < ((cc->key_size << 1) + 1))
- return -ENOMEM;
-
- crypt_encode_key(result + sz, cc->key, cc->key_size);
- sz += cc->key_size << 1;
- } else {
- if (sz >= maxlen)
- return -ENOMEM;
- result[sz++] = '-';
- }
+ if (cc->key_size > 0)
+ for (i = 0; i < cc->key_size; i++)
+ DMEMIT("%02x", cc->key[i]);
+ else
+ DMEMIT("-");
DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
cc->dev->name, (unsigned long long)cc->start);
@@ -1775,7 +1755,6 @@ static int crypt_status(struct dm_target *ti, status_type_t type,
break;
}
- return 0;
}
static void crypt_postsuspend(struct dm_target *ti)
diff --git a/drivers/md/dm-delay.c b/drivers/md/dm-delay.c
index 2dc22dd..ee99912 100644
--- a/drivers/md/dm-delay.c
+++ b/drivers/md/dm-delay.c
@@ -294,8 +294,8 @@ static int delay_map(struct dm_target *ti, struct bio *bio,
return delay_bio(dc, dc->read_delay, bio);
}
-static int delay_status(struct dm_target *ti, status_type_t type,
- char *result, unsigned maxlen)
+static void delay_status(struct dm_target *ti, status_type_t type,
+ char *result, unsigned maxlen)
{
struct delay_c *dc = ti->private;
int sz = 0;
@@ -315,8 +315,6 @@ static int delay_status(struct dm_target *ti, status_type_t type,
dc->write_delay);
break;
}
-
- return 0;
}
static int delay_iterate_devices(struct dm_target *ti,
diff --git a/drivers/md/dm-flakey.c b/drivers/md/dm-flakey.c
index ac49c01..f29d665 100644
--- a/drivers/md/dm-flakey.c
+++ b/drivers/md/dm-flakey.c
@@ -332,8 +332,8 @@ static int flakey_end_io(struct dm_target *ti, struct bio *bio,
return error;
}
-static int flakey_status(struct dm_target *ti, status_type_t type,
- char *result, unsigned int maxlen)
+static void flakey_status(struct dm_target *ti, status_type_t type,
+ char *result, unsigned int maxlen)
{
unsigned sz = 0;
struct flakey_c *fc = ti->private;
@@ -363,7 +363,6 @@ static int flakey_status(struct dm_target *ti, status_type_t type,
break;
}
- return 0;
}
static int flakey_ioctl(struct dm_target *ti, unsigned int cmd, unsigned long arg)
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index f011d4b..d365365 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1066,6 +1066,7 @@ static void retrieve_status(struct dm_table *table,
num_targets = dm_table_get_num_targets(table);
for (i = 0; i < num_targets; i++) {
struct dm_target *ti = dm_table_get_target(table, i);
+ size_t l;
remaining = len - (outptr - outbuf);
if (remaining <= sizeof(struct dm_target_spec)) {
@@ -1089,15 +1090,18 @@ static void retrieve_status(struct dm_table *table,
}
/* Get the status/table string from the target driver */
- if (ti->type->status) {
- if (ti->type->status(ti, type, outptr, remaining)) {
- param->flags |= DM_BUFFER_FULL_FLAG;
- break;
- }
- } else
+ if (ti->type->status)
+ ti->type->status(ti, type, outptr, remaining);
+ else
outptr[0] = '\0';
- outptr += strlen(outptr) + 1;
+ l = strlen(outptr) + 1;
+ if (l == remaining) {
+ param->flags |= DM_BUFFER_FULL_FLAG;
+ break;
+ }
+
+ outptr += l;
used = param->data_start + (outptr - outbuf);
outptr = align_ptr(outptr);
diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 3639eea..5a5e9c8 100644
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -95,8 +95,8 @@ static int linear_map(struct dm_target *ti, struct bio *bio,
return DM_MAPIO_REMAPPED;
}
-static int linear_status(struct dm_target *ti, status_type_t type,
- char *result, unsigned int maxlen)
+static void linear_status(struct dm_target *ti, status_type_t type,
+ char *result, unsigned int maxlen)
{
struct linear_c *lc = (struct linear_c *) ti->private;
@@ -110,7 +110,6 @@ static int linear_status(struct dm_target *ti, status_type_t type,
(unsigned long long)lc->start);
break;
}
- return 0;
}
static int linear_ioctl(struct dm_target *ti, unsigned int cmd,
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 93b3c2d..86a56d8 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -1345,8 +1345,8 @@ static void multipath_resume(struct dm_target *ti)
* [priority selector-name num_ps_args [ps_args]*
* num_paths num_selector_args [path_dev [selector_args]* ]+ ]+
*/
-static int multipath_status(struct dm_target *ti, status_type_t type,
- char *result, unsigned int maxlen)
+static void multipath_status(struct dm_target *ti, status_type_t type,
+ char *result, unsigned int maxlen)
{
int sz = 0;
unsigned long flags;
@@ -1449,8 +1449,6 @@ static int multipath_status(struct dm_target *ti, status_type_t type,
}
spin_unlock_irqrestore(&m->lock, flags);
-
- return 0;
}
static int multipath_message(struct dm_target *ti, unsigned argc, char **argv)
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 017c34d..17def2e 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -1066,8 +1066,8 @@ static int raid_map(struct dm_target *ti, struct bio *bio, union map_info *map_c
return DM_MAPIO_SUBMITTED;
}
-static int raid_status(struct dm_target *ti, status_type_t type,
- char *result, unsigned maxlen)
+static void raid_status(struct dm_target *ti, status_type_t type,
+ char *result, unsigned maxlen)
{
struct raid_set *rs = ti->private;
unsigned raid_param_cnt = 1; /* at least 1 for chunksize */
@@ -1202,8 +1202,6 @@ static int raid_status(struct dm_target *ti, status_type_t type,
DMEMIT(" -");
}
}
-
- return 0;
}
static int raid_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index b58b7a3..a3cf259 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -1362,8 +1362,8 @@ static char device_status_char(struct mirror *m)
}
-static int mirror_status(struct dm_target *ti, status_type_t type,
- char *result, unsigned int maxlen)
+static void mirror_status(struct dm_target *ti, status_type_t type,
+ char *result, unsigned int maxlen)
{
unsigned int m, sz = 0;
struct mirror_set *ms = (struct mirror_set *) ti->private;
@@ -1398,8 +1398,6 @@ static int mirror_status(struct dm_target *ti, status_type_t type,
if (ms->features & DM_RAID1_HANDLE_ERRORS)
DMEMIT(" 1 handle_errors");
}
-
- return 0;
}
static int mirror_iterate_devices(struct dm_target *ti,
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 330bfd6..e106267 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -1845,8 +1845,8 @@ static void snapshot_merge_resume(struct dm_target *ti)
start_merge(s);
}
-static int snapshot_status(struct dm_target *ti, status_type_t type,
- char *result, unsigned int maxlen)
+static void snapshot_status(struct dm_target *ti, status_type_t type,
+ char *result, unsigned int maxlen)
{
unsigned sz = 0;
struct dm_snapshot *snap = ti->private;
@@ -1892,8 +1892,6 @@ static int snapshot_status(struct dm_target *ti, status_type_t type,
maxlen - sz);
break;
}
-
- return 0;
}
static int snapshot_iterate_devices(struct dm_target *ti,
@@ -2148,8 +2146,8 @@ static void origin_resume(struct dm_target *ti)
ti->split_io = get_origin_minimum_chunksize(dev->bdev);
}
-static int origin_status(struct dm_target *ti, status_type_t type, char *result,
- unsigned int maxlen)
+static void origin_status(struct dm_target *ti, status_type_t type, char *result,
+ unsigned int maxlen)
{
struct dm_dev *dev = ti->private;
@@ -2162,8 +2160,6 @@ static int origin_status(struct dm_target *ti, status_type_t type, char *result,
snprintf(result, maxlen, "%s", dev->name);
break;
}
-
- return 0;
}
static int origin_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index 35c94ff..58ffcda 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -302,8 +302,8 @@ static int stripe_map(struct dm_target *ti, struct bio *bio,
*
*/
-static int stripe_status(struct dm_target *ti,
- status_type_t type, char *result, unsigned int maxlen)
+static void stripe_status(struct dm_target *ti,
+ status_type_t type, char *result, unsigned int maxlen)
{
struct stripe_c *sc = (struct stripe_c *) ti->private;
char buffer[sc->stripes + 1];
@@ -330,7 +330,6 @@ static int stripe_status(struct dm_target *ti,
(unsigned long long)sc->stripe[i].physical_start);
break;
}
- return 0;
}
static int stripe_end_io(struct dm_target *ti, struct bio *bio,
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 1307ba8..7ef83d9 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -2378,8 +2378,8 @@ static int pool_message(struct dm_target *ti, unsigned argc, char **argv)
* <transaction id> <used metadata sectors>/<total metadata sectors>
* <used data sectors>/<total data sectors> <held metadata root>
*/
-static int pool_status(struct dm_target *ti, status_type_t type,
- char *result, unsigned maxlen)
+static void pool_status(struct dm_target *ti, status_type_t type,
+ char *result, unsigned maxlen)
{
int r, count;
unsigned sz = 0;
@@ -2396,32 +2396,41 @@ static int pool_status(struct dm_target *ti, status_type_t type,
switch (type) {
case STATUSTYPE_INFO:
- r = dm_pool_get_metadata_transaction_id(pool->pmd,
- &transaction_id);
- if (r)
- return r;
+ r = dm_pool_get_metadata_transaction_id(pool->pmd, &transaction_id);
+ if (r) {
+ DMERR("dm_pool_get_metadata_transaction_id returned %d", r);
+ goto err;
+ }
- r = dm_pool_get_free_metadata_block_count(pool->pmd,
- &nr_free_blocks_metadata);
- if (r)
- return r;
+ r = dm_pool_get_free_metadata_block_count(pool->pmd, &nr_free_blocks_metadata);
+ if (r) {
+ DMERR("dm_pool_get_free_metadata_block_count returned %d", r);
+ goto err;
+ }
r = dm_pool_get_metadata_dev_size(pool->pmd, &nr_blocks_metadata);
- if (r)
- return r;
+ if (r) {
+ DMERR("dm_pool_get_metadata_dev_size returned %d", r);
+ goto err;
+ }
- r = dm_pool_get_free_block_count(pool->pmd,
- &nr_free_blocks_data);
- if (r)
- return r;
+ r = dm_pool_get_free_block_count(pool->pmd, &nr_free_blocks_data);
+ if (r) {
+ DMERR("dm_pool_get_free_block_count returned %d", r);
+ goto err;
+ }
r = dm_pool_get_data_dev_size(pool->pmd, &nr_blocks_data);
- if (r)
- return r;
+ if (r) {
+ DMERR("dm_pool_get_data_dev_size returned %d", r);
+ goto err;
+ }
r = dm_pool_get_metadata_snap(pool->pmd, &held_root);
- if (r)
- return r;
+ if (r) {
+ DMERR("dm_pool_get_metadata_snap returned %d", r);
+ goto err;
+ }
DMEMIT("%llu %llu/%llu %llu/%llu ",
(unsigned long long)transaction_id,
@@ -2459,8 +2468,10 @@ static int pool_status(struct dm_target *ti, status_type_t type,
break;
}
+ return;
- return 0;
+err:
+ DMEMIT("Error");
}
static int pool_iterate_devices(struct dm_target *ti,
@@ -2712,8 +2723,8 @@ static void thin_postsuspend(struct dm_target *ti)
/*
* <nr mapped sectors> <highest mapped sector>
*/
-static int thin_status(struct dm_target *ti, status_type_t type,
- char *result, unsigned maxlen)
+static void thin_status(struct dm_target *ti, status_type_t type,
+ char *result, unsigned maxlen)
{
int r;
ssize_t sz = 0;
@@ -2727,12 +2738,16 @@ static int thin_status(struct dm_target *ti, status_type_t type,
switch (type) {
case STATUSTYPE_INFO:
r = dm_thin_get_mapped_count(tc->td, &mapped);
- if (r)
- return r;
+ if (r) {
+ DMERR("dm_thin_get_mapped_count returned %d", r);
+ goto err;
+ }
r = dm_thin_get_highest_mapped_block(tc->td, &highest);
- if (r < 0)
- return r;
+ if (r < 0) {
+ DMERR("dm_thin_get_highest_mapped_block returned %d", r);
+ goto err;
+ }
DMEMIT("%llu ", mapped * tc->pool->sectors_per_block);
if (r)
@@ -2752,7 +2767,10 @@ static int thin_status(struct dm_target *ti, status_type_t type,
}
}
- return 0;
+ return;
+
+err:
+ DMEMIT("Error");
}
static int thin_iterate_devices(struct dm_target *ti,
diff --git a/drivers/md/dm-verity.c b/drivers/md/dm-verity.c
index 157007d..ca36692 100644
--- a/drivers/md/dm-verity.c
+++ b/drivers/md/dm-verity.c
@@ -543,8 +543,8 @@ static int verity_map(struct dm_target *ti, struct bio *bio,
/*
* Status: V (valid) or C (corruption found)
*/
-static int verity_status(struct dm_target *ti, status_type_t type,
- char *result, unsigned maxlen)
+static void verity_status(struct dm_target *ti, status_type_t type,
+ char *result, unsigned maxlen)
{
struct dm_verity *v = ti->private;
unsigned sz = 0;
@@ -575,8 +575,6 @@ static int verity_status(struct dm_target *ti, status_type_t type,
DMEMIT("%02x", v->salt[x]);
break;
}
-
- return 0;
}
static int verity_ioctl(struct dm_target *ti, unsigned cmd,
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 98f34b8..fa09b57 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -72,8 +72,8 @@ typedef void (*dm_postsuspend_fn) (struct dm_target *ti);
typedef int (*dm_preresume_fn) (struct dm_target *ti);
typedef void (*dm_resume_fn) (struct dm_target *ti);
-typedef int (*dm_status_fn) (struct dm_target *ti, status_type_t status_type,
- char *result, unsigned int maxlen);
+typedef void (*dm_status_fn) (struct dm_target *ti, status_type_t status_type,
+ char *result, unsigned int maxlen);
typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv);
--
1.8.3.2
--
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