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authorZhangXiaoxu <zhangxiaoxu5@huawei.com>2019-04-06 15:47:39 +0800
committerSteve French <stfrench@microsoft.com>2019-04-16 09:38:21 -0500
commit088aaf17aa79300cab14dbee2569c58cfafd7d6e (patch)
tree2df560323e5b037a268ada67ab3cc84fb7b35eb3
parent6a3eb3360667170988f8a6477f6686242061488a (diff)
cifs: Fix use-after-free in SMB2_read
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>
-rw-r--r--fs/cifs/smb2pdu.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 5d1f8d2d44e4..5d6adc63ad62 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -3448,8 +3448,6 @@ SMB2_read(const unsigned int xid, struct cifs_io_parms *io_parms,
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) {
@@ -3471,6 +3469,8 @@ SMB2_read(const unsigned int xid, struct cifs_io_parms *io_parms,
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)) {