From: Jordy Zomer <jordyzomer@xxxxxxxxxx> commit 313dab082289e460391c82d855430ec8a28ddf81 upstream. An offset from client could be a negative value, It could allows to write data outside the bounds of the allocated buffer. Note that this issue is coming when setting 'vfs objects = streams_xattr parameter' in ksmbd.conf. Cc: stable@xxxxxxxxxxxxxxx # v5.15+ Reported-by: Jordy Zomer <jordyzomer@xxxxxxxxxx> Signed-off-by: Jordy Zomer <jordyzomer@xxxxxxxxxx> 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 | 2 ++ 1 file changed, 2 insertions(+) --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -6587,6 +6587,8 @@ int smb2_write(struct ksmbd_work *work) } offset = le64_to_cpu(req->Offset); + if (offset < 0) + return -EINVAL; length = le32_to_cpu(req->Length); if (req->Channel == SMB2_CHANNEL_RDMA_V1 || Patches currently in stable-queue which might be from jordyzomer@xxxxxxxxxx are queue-6.1/ksmbd-fix-out-of-bounds-write-in-ksmbd_vfs_stream_write.patch queue-6.1/ksmbd-fix-out-of-bounds-read-in-ksmbd_vfs_stream_read.patch
