A sufficiently long Unit Serial string, dbroot path, and/or ALUA target
portal group name may result in truncation of the ALUA state file path
prior to usage. Add checks for snprintf() truncation.
Fixes: fdddf932269a ("target: use new "dbroot" target attribute")
Signed-off-by: David Disseldorp <ddiss@xxxxxxx>
---
drivers/target/target_core_alua.c | 37 ++++++++++++++++++++++++++-----------
1 file changed, 26 insertions(+), 11 deletions(-)
diff --git a/drivers/target/target_core_alua.c b/drivers/target/target_core_alua.c
index 928127642574..2351fe60c0e7 100644
--- a/drivers/target/target_core_alua.c
+++ b/drivers/target/target_core_alua.c
@@ -921,14 +921,23 @@ static int core_alua_update_tpg_primary_metadata(
char path[ALUA_METADATA_PATH_LEN];
int len, rc;
+ memset(path, 0, ALUA_METADATA_PATH_LEN);
+
+ len = snprintf(path, ALUA_METADATA_PATH_LEN,
+ "%s/alua/tpgs_%s/%s", db_root, &wwn->unit_serial[0],
+ config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
+ if (len >= ALUA_METADATA_PATH_LEN) {
+ pr_err("WWN value for struct se_device does not fit"
+ " into path buffer\n");
+ return -EMSGSIZE;
+ }
+
md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
if (!md_buf) {
pr_err("Unable to allocate buf for ALUA metadata\n");
return -ENOMEM;
}
- memset(path, 0, ALUA_METADATA_PATH_LEN);
-
len = snprintf(md_buf, ALUA_MD_BUF_LEN,
"tg_pt_gp_id=%hu\n"
"alua_access_state=0x%02x\n"
@@ -937,10 +946,6 @@ static int core_alua_update_tpg_primary_metadata(
tg_pt_gp->tg_pt_gp_alua_access_state,
tg_pt_gp->tg_pt_gp_alua_access_status);
- snprintf(path, ALUA_METADATA_PATH_LEN,
- "%s/alua/tpgs_%s/%s", db_root, &wwn->unit_serial[0],
- config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
-
rc = core_alua_write_tpg_metadata(path, md_buf, len);
kfree(md_buf);
return rc;
@@ -1231,18 +1236,28 @@ static int core_alua_update_tpg_secondary_metadata(struct se_lun *lun)
snprintf(wwn+len, ALUA_SECONDARY_METADATA_WWN_LEN-len, "+%hu",
se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
+ len = snprintf(path, ALUA_METADATA_PATH_LEN, "%s/alua/%s/%s/lun_%llu",
+ db_root, se_tpg->se_tpg_tfo->get_fabric_name(), wwn,
+ lun->unpacked_lun);
+ if (len >= ALUA_METADATA_PATH_LEN) {
+ pr_err("WWN value for struct se_device does not fit"
+ " into path buffer\n");
+ rc = -EMSGSIZE;
+ goto out_free;
+ }
+
len = snprintf(md_buf, ALUA_MD_BUF_LEN, "alua_tg_pt_offline=%d\n"
"alua_tg_pt_status=0x%02x\n",
atomic_read(&lun->lun_tg_pt_secondary_offline),
lun->lun_tg_pt_secondary_stat);
-
- snprintf(path, ALUA_METADATA_PATH_LEN, "%s/alua/%s/%s/lun_%llu",
- db_root, se_tpg->se_tpg_tfo->get_fabric_name(), wwn,
- lun->unpacked_lun);
+ if (len >= ALUA_MD_BUF_LEN) {
+ rc = -EMSGSIZE;
+ goto out_free;
+ }
rc = core_alua_write_tpg_metadata(path, md_buf, len);
+out_free:
kfree(md_buf);
-
out_unlock:
mutex_unlock(&lun->lun_tg_pt_md_mutex);
return rc;
--
2.13.6
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