Commit 6fd13d69 authored by Andrea Parri (Microsoft)'s avatar Andrea Parri (Microsoft) Committed by Martin K. Petersen

scsi: storvsc: Fix validation for unsolicited incoming packets

The validation on the length of incoming packets performed in
storvsc_on_channel_callback() does not apply to unsolicited packets with ID
of 0 sent by Hyper-V.  Adjust the validation for such unsolicited packets.

Link: https://lore.kernel.org/r/20211007122828.469289-1-parri.andrea@gmail.com
Fixes: 91b1b640 ("scsi: storvsc: Validate length of incoming packet in storvsc_on_channel_callback()")
Reported-by: default avatarDexuan Cui <decui@microsoft.com>
Reviewed-by: default avatarMichael Kelley <mikelley@microsoft.com>
Reviewed-by: default avatarHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: default avatarAndrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 187a580c
......@@ -1285,11 +1285,15 @@ static void storvsc_on_channel_callback(void *context)
foreach_vmbus_pkt(desc, channel) {
struct vstor_packet *packet = hv_pkt_data(desc);
struct storvsc_cmd_request *request = NULL;
u32 pktlen = hv_pkt_datalen(desc);
u64 rqst_id = desc->trans_id;
u32 minlen = rqst_id ? sizeof(struct vstor_packet) -
stor_device->vmscsi_size_delta : sizeof(enum vstor_packet_operation);
if (hv_pkt_datalen(desc) < sizeof(struct vstor_packet) -
stor_device->vmscsi_size_delta) {
dev_err(&device->device, "Invalid packet len\n");
if (pktlen < minlen) {
dev_err(&device->device,
"Invalid pkt: id=%llu, len=%u, minlen=%u\n",
rqst_id, pktlen, minlen);
continue;
}
......@@ -1302,13 +1306,23 @@ static void storvsc_on_channel_callback(void *context)
if (rqst_id == 0) {
/*
* storvsc_on_receive() looks at the vstor_packet in the message
* from the ring buffer. If the operation in the vstor_packet is
* COMPLETE_IO, then we call storvsc_on_io_completion(), and
* dereference the guest memory address. Make sure we don't call
* storvsc_on_io_completion() with a guest memory address that is
* zero if Hyper-V were to construct and send such a bogus packet.
* from the ring buffer.
*
* - If the operation in the vstor_packet is COMPLETE_IO, then
* we call storvsc_on_io_completion(), and dereference the
* guest memory address. Make sure we don't call
* storvsc_on_io_completion() with a guest memory address
* that is zero if Hyper-V were to construct and send such
* a bogus packet.
*
* - If the operation in the vstor_packet is FCHBA_DATA, then
* we call cache_wwn(), and access the data payload area of
* the packet (wwn_packet); however, there is no guarantee
* that the packet is big enough to contain such area.
* Future-proof the code by rejecting such a bogus packet.
*/
if (packet->operation == VSTOR_OPERATION_COMPLETE_IO) {
if (packet->operation == VSTOR_OPERATION_COMPLETE_IO ||
packet->operation == VSTOR_OPERATION_FCHBA_DATA) {
dev_err(&device->device, "Invalid packet with ID of 0\n");
continue;
}
......
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