From: Namjae Jeon linkinjeon@kernel.org
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@vger.kernel.org Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-21598 Signed-off-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ksmbd/smb2pdu.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
--- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -2309,9 +2309,16 @@ 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);