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authorCezar Bulinaru <cbulinaru@gmail.com>2022-10-14 05:45:03 +0300
committerDavid S. Miller <davem@davemloft.net>2022-10-15 13:09:53 +0300
commit017e42540639a46fdf7c7f5ee647e0b7806c9013 (patch)
tree5490a4634a84a2157efba2a8b28707c09a9d81ff
parentd8bde3bf7f82dac5fc68a62c2816793a12cafa2a (diff)
downloadlinux-017e42540639a46fdf7c7f5ee647e0b7806c9013.tar.xz
net: hv_netvsc: Fix a warning triggered by memcpy in rndis_filter
memcpy: detected field-spanning write (size 168) of single field "(void *)&request->response_msg + (sizeof(struct rndis_message) - sizeof(union rndis_message_container)) + sizeof(*req_id)" at drivers/net/hyperv/rndis_filter.c:338 (size 40) RSP: 0018:ffffc90000144de0 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff8881766b4000 RCX: 0000000000000000 RDX: 0000000000000102 RSI: 0000000000009ffb RDI: 00000000ffffffff RBP: ffffc90000144e38 R08: 0000000000000000 R09: 00000000ffffdfff R10: ffffc90000144c48 R11: ffffffff82f56ac8 R12: ffff8881766b403c R13: 00000000000000a8 R14: ffff888100b75000 R15: ffff888179301d00 FS: 0000000000000000(0000) GS:ffff8884d6280000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f8b024c418 CR3: 0000000176548001 CR4: 00000000003706e0 Call Trace: <IRQ> ? _raw_spin_unlock_irqrestore+0x27/0x50 netvsc_poll+0x556/0x940 [hv_netvsc] __napi_poll+0x2e/0x170 net_rx_action+0x299/0x2f0 __do_softirq+0xed/0x2ef __irq_exit_rcu+0x9f/0x110 irq_exit_rcu+0xe/0x20 sysvec_hyperv_callback+0xb0/0xd0 </IRQ> <TASK> asm_sysvec_hyperv_callback+0x1b/0x20 RIP: 0010:native_safe_halt+0xb/0x10 Fixes: A warning triggered when the response message len exceeds the size of rndis_message. Inside the rndis_request structure these fields are however followed by a RNDIS_EXT_LEN padding so it is safe to use unsafe_memcpy. Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Cezar Bulinaru <cbulinaru@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/hyperv/rndis_filter.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index 11f767a20444..eea777ec2541 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -20,6 +20,7 @@
#include <linux/vmalloc.h>
#include <linux/rtnetlink.h>
#include <linux/ucs2_string.h>
+#include <linux/string.h>
#include "hyperv_net.h"
#include "netvsc_trace.h"
@@ -335,9 +336,10 @@ static void rndis_filter_receive_response(struct net_device *ndev,
if (resp->msg_len <=
sizeof(struct rndis_message) + RNDIS_EXT_LEN) {
memcpy(&request->response_msg, resp, RNDIS_HEADER_SIZE + sizeof(*req_id));
- memcpy((void *)&request->response_msg + RNDIS_HEADER_SIZE + sizeof(*req_id),
+ unsafe_memcpy((void *)&request->response_msg + RNDIS_HEADER_SIZE + sizeof(*req_id),
data + RNDIS_HEADER_SIZE + sizeof(*req_id),
- resp->msg_len - RNDIS_HEADER_SIZE - sizeof(*req_id));
+ resp->msg_len - RNDIS_HEADER_SIZE - sizeof(*req_id),
+ "request->response_msg is followed by a padding of RNDIS_EXT_LEN inside rndis_request");
if (request->request_msg.ndis_msg_type ==
RNDIS_MSG_QUERY && request->request_msg.msg.
query_req.oid == RNDIS_OID_GEN_MEDIA_CONNECT_STATUS)