lkml.org 
[lkml]   [2022]   [Nov]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH AUTOSEL 6.0 34/39] 9p/xen: check logical size for buffer size
Date
From: Dominique Martinet <asmadeus@codewreck.org>

[ Upstream commit 391c18cf776eb4569ecda1f7794f360fe0a45a26 ]

trans_xen did not check the data fits into the buffer before copying
from the xen ring, but we probably should.
Add a check that just skips the request and return an error to
userspace if it did not fit

Tested-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com>
Link: https://lkml.kernel.org/r/20221118135542.63400-1-asmadeus@codewreck.org
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/9p/trans_xen.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c
index 227f89cc7237..0f862d5a5960 100644
--- a/net/9p/trans_xen.c
+++ b/net/9p/trans_xen.c
@@ -208,6 +208,14 @@ static void p9_xen_response(struct work_struct *work)
continue;
}

+ if (h.size > req->rc.capacity) {
+ dev_warn(&priv->dev->dev,
+ "requested packet size too big: %d for tag %d with capacity %zd\n",
+ h.size, h.tag, req->rc.capacity);
+ req->status = REQ_STATUS_ERROR;
+ goto recv_error;
+ }
+
memcpy(&req->rc, &h, sizeof(h));
req->rc.offset = 0;

@@ -217,6 +225,7 @@ static void p9_xen_response(struct work_struct *work)
masked_prod, &masked_cons,
XEN_9PFS_RING_SIZE(ring));

+recv_error:
virt_mb();
cons += h.size;
ring->intf->in_cons = cons;
--
2.35.1
\
 
 \ /
  Last update: 2022-11-28 18:43    [W:0.096 / U:1.100 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site