FAILED: patch "[PATCH] dm integrity: change memcmp to strncmp in dm_integrity_ctr" failed to apply to 4.14-stable tree

PATCH In review [email protected] 2 participants 3 messages Apr 15, 2019 – Apr 29, 2019

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[email protected]

author maintainer

2019-04-15 16:37 UTC #0 lore raw

The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 0d74e6a3b6421d98eeafbed26f29156d469bc0b5 Mon Sep 17 00:00:00 2001
From: Mikulas Patocka <[email protected]>
Date: Wed, 13 Mar 2019 07:56:02 -0400
Subject: [PATCH] dm integrity: change memcmp to strncmp in dm_integrity_ctr

If the string opt_string is small, the function memcmp can access bytes that are beyond the terminating nul character. In theory, it could cause segfault, if opt_string were located just below some unmapped memory.

Change from memcmp to strncmp so that we don't read bytes beyond the end of the string.

Cc [email protected] # v4.12+

Signed-off-by Mikulas Patocka <[email protected]>

Signed-off-by Mike Snitzer <[email protected]>

drivers/md/dm-integrity.c +4 -4

index d57d997a52c8..33fac437569f 100644
@@ -3185,7 +3185,7 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv)
 			journal_watermark = val;
 		else if (sscanf(opt_string, "commit_time:%u%c", &val, &dummy) == 1)
 			sync_msec = val;
-		else if (!memcmp(opt_string, "meta_device:", strlen("meta_device:"))) {
+		else if (!strncmp(opt_string, "meta_device:", strlen("meta_device:"))) {
 			if (ic->meta_dev) {
 				dm_put_device(ti, ic->meta_dev);
 				ic->meta_dev = NULL;

@@ -3204,17 +3204,17 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv)
 				goto bad;
 			}
 			ic->sectors_per_block = val >> SECTOR_SHIFT;
-		} else if (!memcmp(opt_string, "internal_hash:", strlen("internal_hash:"))) {
+		} else if (!strncmp(opt_string, "internal_hash:", strlen("internal_hash:"))) {
 			r = get_alg_and_key(opt_string, &ic->internal_hash_alg, &ti->error,
 					    "Invalid internal_hash argument");
 			if (r)
 				goto bad;
-		} else if (!memcmp(opt_string, "journal_crypt:", strlen("journal_crypt:"))) {
+		} else if (!strncmp(opt_string, "journal_crypt:", strlen("journal_crypt:"))) {
 			r = get_alg_and_key(opt_string, &ic->journal_crypt_alg, &ti->error,
 					    "Invalid journal_crypt argument");
 			if (r)
 				goto bad;
-		} else if (!memcmp(opt_string, "journal_mac:", strlen("journal_mac:"))) {
+		} else if (!strncmp(opt_string, "journal_mac:", strlen("journal_mac:"))) {
 			r = get_alg_and_key(opt_string, &ic->journal_mac_alg,  &ti->error,
 					    "Invalid journal_mac argument");
 			if (r)

Mikulas Patocka

maintainer

2019-04-16 08:44 UTC #1 lore raw

PATCH 1/1 dm integrity: change memcmp to strncmp in dm_integrity_ctr

Hi.

Here I'm sending the patch backported for the kernel 4.14.

Mikulas

From [email protected] Mon Apr 15 12:38:03 2019
Date: Mon, 15 Apr 2019 18:37:16 +0200
From: [email protected]
To: [email protected], [email protected]
Cc: [email protected]
Subject: FAILED: patch "[PATCH] dm integrity: change memcmp to strncmp in dm_integrity_ctr" failed to apply to 4.14-stable tree

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

Quoted 1 line

From 0d74e6a3b6421d98eeafbed26f29156d469bc0b5 Mon Sep 17 00:00:00 2001

From: Mikulas Patocka <[email protected]>
Date: Wed, 13 Mar 2019 07:56:02 -0400
Subject: [PATCH] dm integrity: change memcmp to strncmp in dm_integrity_ctr

Change from memcmp to strncmp so that we don't read bytes beyond the end of the string.

Cc [email protected] # v4.12+

Signed-off-by Mikulas Patocka <[email protected]>

Signed-off-by Mike Snitzer <[email protected]>

---
 drivers/md/dm-integrity.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

drivers/md/dm-integrity.c +3 -3

Index: linux-stable/drivers/md/dm-integrity.c
===================================================================
@@ -2889,17 +2889,17 @@ static int dm_integrity_ctr(struct dm_ta
 				goto bad;
 			}
 			ic->sectors_per_block = val >> SECTOR_SHIFT;
-		} else if (!memcmp(opt_string, "internal_hash:", strlen("internal_hash:"))) {
+		} else if (!strncmp(opt_string, "internal_hash:", strlen("internal_hash:"))) {
 			r = get_alg_and_key(opt_string, &ic->internal_hash_alg, &ti->error,
 					    "Invalid internal_hash argument");
 			if (r)
 				goto bad;
-		} else if (!memcmp(opt_string, "journal_crypt:", strlen("journal_crypt:"))) {
+		} else if (!strncmp(opt_string, "journal_crypt:", strlen("journal_crypt:"))) {
 			r = get_alg_and_key(opt_string, &ic->journal_crypt_alg, &ti->error,
 					    "Invalid journal_crypt argument");
 			if (r)
 				goto bad;
-		} else if (!memcmp(opt_string, "journal_mac:", strlen("journal_mac:"))) {
+		} else if (!strncmp(opt_string, "journal_mac:", strlen("journal_mac:"))) {
 			r = get_alg_and_key(opt_string, &ic->journal_mac_alg,  &ti->error,
 					    "Invalid journal_mac argument");
 			if (r)

Greg KH

author maintainer

2019-04-29 12:42 UTC #2 lore raw

Re: [PATCH] dm integrity: change memcmp to strncmp in dm_integrity_ctr

Quoted 3 lines · Mikulas Patocka

Hi.
Here I'm sending the patch backported for the kernel 4.14.

Thanks, now queued up.

greg k-h