[Devel] [PATCH RHEL8 COMMIT] ploop: Add check device is not wider than BAT

[Konstantin Khorenko]

The commit is pushed to "branch-rh8-4.18.0-305.3.1.vz8.7.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh8-4.18.0-305.3.1.vz8.7.6
------>
commit fabccc2df00df07dfb1b64c0f9a76c164e18e133
Author: Kirill Tkhai <ktkhai at virtuozzo.com>
Date:   Fri Aug 13 15:41:26 2021 +0300

    ploop: Add check device is not wider than BAT
    
    https://jira.sw.ru/browse/PSBM-132803
    Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
---
 drivers/md/dm-ploop-bat.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/md/dm-ploop-bat.c b/drivers/md/dm-ploop-bat.c
index f2a2d35818b8..44cbce6f6b40 100644
--- a/drivers/md/dm-ploop-bat.c
+++ b/drivers/md/dm-ploop-bat.c
@@ -269,6 +269,7 @@ int ploop_setup_metadata(struct ploop *ploop, struct page *page)
 {
 	struct ploop_pvd_header *m_hdr = NULL;
 	u32 bat_clusters, offset_clusters;
+	struct dm_target *ti = ploop->ti;
 	unsigned long size;
 	int ret;
 
@@ -302,6 +303,11 @@ int ploop_setup_metadata(struct ploop *ploop, struct page *page)
 		pr_err("ploop: custom FirstBlockOffset\n");
 		goto out;
 	}
+	ret = -EBADSLT;
+	if (le64_to_cpu(m_hdr->m_SizeInSectors_v2) < ti->len) {
+		pr_err("ploop: Too short BAT\n");
+		goto out;
+	}
 	kunmap(page);
 	m_hdr = NULL;