From: Namjae Jeon <linkinjeon@xxxxxxxxxx>
commit 79ed288cef201f1f212dfb934bcaac75572fb8f6 upstream.
There are multiple smb2_ea_info buffers in FILE_FULL_EA_INFORMATION request
from client. ksmbd find next smb2_ea_info using ->NextEntryOffset of
current smb2_ea_info. ksmbd need to validate buffer length Before
accessing the next ea. ksmbd should check buffer length using buf_len,
not next variable. next is the start offset of current ea that got from
previous ea.
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: zdi-disclosures@xxxxxxxxxxxxxx # ZDI-CAN-21598
Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/smb/server/smb2pdu.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
--- a/fs/smb/server/smb2pdu.c
+++ b/fs/smb/server/smb2pdu.c
@@ -2340,9 +2340,16 @@ next:
break;
buf_len -= next;
eabuf = (struct smb2_ea_info *)((char *)eabuf + next);
- if (next < (u32)eabuf->EaNameLength + le16_to_cpu(eabuf->EaValueLength))
+ if (buf_len < sizeof(struct smb2_ea_info)) {
+ rc = -EINVAL;
break;
+ }
+ if (buf_len < sizeof(struct smb2_ea_info) + eabuf->EaNameLength +
+ le16_to_cpu(eabuf->EaValueLength)) {
+ rc = -EINVAL;
+ break;
+ }
} while (next != 0);
kfree(attr_name);
