From 8fb89b43b65fcd35f15d982712904b96fc64c68a Mon Sep 17 00:00:00 2001 From: ZhangXiaoxu Date: Sat, 6 Apr 2019 15:47:38 +0800 Subject: cifs: Fix use-after-free in SMB2_write commit 6a3eb3360667170988f8a6477f6686242061488a upstream. There is a KASAN use-after-free: BUG: KASAN: use-after-free in SMB2_write+0x1342/0x1580 Read of size 8 at addr ffff8880b6a8e450 by task ln/4196 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 Signed-off-by: Steve French CC: Stable 4.18+ Reviewed-by: Pavel Shilovsky Signed-off-by: Greg Kroah-Hartman --- fs/cifs/smb2pdu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 71f32d983384..299d8e46f01f 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -3591,7 +3591,6 @@ SMB2_write(const unsigned int xid, struct cifs_io_parms *io_parms, rc = cifs_send_recv(xid, io_parms->tcon->ses, &rqst, &resp_buftype, flags, &rsp_iov); - cifs_small_buf_release(req); rsp = (struct smb2_write_rsp *)rsp_iov.iov_base; if (rc) { @@ -3609,6 +3608,7 @@ SMB2_write(const unsigned int xid, struct cifs_io_parms *io_parms, io_parms->offset, *nbytes); } + cifs_small_buf_release(req); free_rsp_buf(resp_buftype, rsp); return rc; } -- cgit v1.2.3