5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Namjae Jeon <linkinjeon@xxxxxxxxxx>
[ Upstream commit eebff19acaa35820cb09ce2ccb3d21bee2156ffb ]
slab out-of-bounds write is caused by that offsets is bigger than pntsd
allocation size. This patch add the check to validate 3 offsets using
allocation size.
Reported-by: zdi-disclosures@xxxxxxxxxxxxxx # ZDI-CAN-22271
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/ksmbd/smbacl.c | 29 ++++++++++++++++++++++++++---
1 file changed, 26 insertions(+), 3 deletions(-)
diff --git a/fs/ksmbd/smbacl.c b/fs/ksmbd/smbacl.c
index 3781bca2c8fc4..83f805248a814 100644
--- a/fs/ksmbd/smbacl.c
+++ b/fs/ksmbd/smbacl.c
@@ -1105,6 +1105,7 @@ int smb_inherit_dacl(struct ksmbd_conn *conn,
struct smb_acl *pdacl;
struct smb_sid *powner_sid = NULL, *pgroup_sid = NULL;
int powner_sid_size = 0, pgroup_sid_size = 0, pntsd_size;
+ int pntsd_alloc_size;
if (parent_pntsd->osidoffset) {
powner_sid = (struct smb_sid *)((char *)parent_pntsd +
@@ -1117,9 +1118,10 @@ int smb_inherit_dacl(struct ksmbd_conn *conn,
pgroup_sid_size = 1 + 1 + 6 + (pgroup_sid->num_subauth * 4);
}
- pntsd = kzalloc(sizeof(struct smb_ntsd) + powner_sid_size +
- pgroup_sid_size + sizeof(struct smb_acl) +
- nt_size, GFP_KERNEL);
+ pntsd_alloc_size = sizeof(struct smb_ntsd) + powner_sid_size +
+ pgroup_sid_size + sizeof(struct smb_acl) + nt_size;
+
+ pntsd = kzalloc(pntsd_alloc_size, GFP_KERNEL);
if (!pntsd) {
rc = -ENOMEM;
goto free_aces_base;
@@ -1134,6 +1136,27 @@ int smb_inherit_dacl(struct ksmbd_conn *conn,
pntsd->gsidoffset = parent_pntsd->gsidoffset;
pntsd->dacloffset = parent_pntsd->dacloffset;
+ if ((u64)le32_to_cpu(pntsd->osidoffset) + powner_sid_size >
+ pntsd_alloc_size) {
+ rc = -EINVAL;
+ kfree(pntsd);
+ goto free_aces_base;
+ }
+
+ if ((u64)le32_to_cpu(pntsd->gsidoffset) + pgroup_sid_size >
+ pntsd_alloc_size) {
+ rc = -EINVAL;
+ kfree(pntsd);
+ goto free_aces_base;
+ }
+
+ if ((u64)le32_to_cpu(pntsd->dacloffset) + sizeof(struct smb_acl) + nt_size >
+ pntsd_alloc_size) {
+ rc = -EINVAL;
+ kfree(pntsd);
+ goto free_aces_base;
+ }
+
if (pntsd->osidoffset) {
struct smb_sid *owner_sid = (struct smb_sid *)((char *)pntsd +
le32_to_cpu(pntsd->osidoffset));
--
2.42.0
