MFC r305193: MFV r302642:

6876 Stack corruption after importing a pool with a too-long name

illumos/illumos-gate@c971037baa5d64dfecf6d87ed602fc3116ebec41
https://github.com/illumos/illumos-gate/commit/c971037baa5d64dfecf6d87ed602fc3116ebec41

https://www.illumos.org/issues/6876
  Calling dsl_dataset_name on a dataset with a 256 byte buffer is asking for
  trouble. We should check every dataset on import, using a 1024 byte buffer and
  checking each time to see if the dataset's new name is longer than 256 bytes.

Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Yuri Pankov <yuri.pankov@nexenta.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
Author: Paul Dagnelie <pcd@delphix.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c
index c31f981..ee2e93b 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c
@@ -1975,6 +1975,19 @@ spa_load_verify_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
 	return (0);
 }
 
+/* ARGSUSED */
+int
+verify_dataset_name_len(dsl_pool_t *dp, dsl_dataset_t *ds, void *arg)
+{
+	char namebuf[MAXPATHLEN];
+	dsl_dataset_name(ds, namebuf);
+	if (strlen(namebuf) > MAXNAMELEN) {
+		return (SET_ERROR(ENAMETOOLONG));
+	}
+
+	return (0);
+}
+
 static int
 spa_load_verify(spa_t *spa)
 {
@@ -1989,6 +2002,14 @@ spa_load_verify(spa_t *spa)
 	if (policy.zrp_request & ZPOOL_NEVER_REWIND)
 		return (0);
 
+	dsl_pool_config_enter(spa->spa_dsl_pool, FTAG);
+	error = dmu_objset_find_dp(spa->spa_dsl_pool,
+	    spa->spa_dsl_pool->dp_root_dir_obj, verify_dataset_name_len, NULL,
+	    DS_FIND_CHILDREN);
+	dsl_pool_config_exit(spa->spa_dsl_pool, FTAG);
+	if (error != 0)
+		return (error);
+
 	rio = zio_root(spa, NULL, &sle,
 	    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE);