From: ZhangXiaoxu zhangxiaoxu5@huawei.com
commit 088aaf17aa79300cab14dbee2569c58cfafd7d6e upstream.
There is a KASAN use-after-free: BUG: KASAN: use-after-free in SMB2_read+0x1136/0x1190 Read of size 8 at addr ffff8880b4e45e50 by task ln/1009
Should not release the 'req' because it will use in the trace.
Fixes: eccb4422cf97 ("smb3: Add ftrace tracepoints for improved SMB3 debugging")
Signed-off-by: ZhangXiaoxu zhangxiaoxu5@huawei.com Signed-off-by: Steve French stfrench@microsoft.com CC: Stable stable@vger.kernel.org 4.18+ Reviewed-by: Pavel Shilovsky pshilov@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/cifs/smb2pdu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -3390,8 +3390,6 @@ SMB2_read(const unsigned int xid, struct rqst.rq_nvec = 1;
rc = cifs_send_recv(xid, ses, &rqst, &resp_buftype, flags, &rsp_iov); - cifs_small_buf_release(req); - rsp = (struct smb2_read_rsp *)rsp_iov.iov_base;
if (rc) { @@ -3410,6 +3408,8 @@ SMB2_read(const unsigned int xid, struct io_parms->tcon->tid, ses->Suid, io_parms->offset, io_parms->length);
+ cifs_small_buf_release(req); + *nbytes = le32_to_cpu(rsp->DataLength); if ((*nbytes > CIFS_MAX_MSGSIZE) || (*nbytes > io_parms->length)) {