124 lines
3.7 KiB
Diff
124 lines
3.7 KiB
Diff
From 960dbb956d9f9cb05b719087faed53c88dc80956 Mon Sep 17 00:00:00 2001
|
|
From: Chrostoper Ertl <chertl@microsoft.com>
|
|
Date: Thu, 28 Nov 2019 16:33:59 +0000
|
|
Subject: [PATCH 06/11] fru: Fix buffer overflow vulnerabilities
|
|
|
|
Partial fix for CVE-2020-5208, see
|
|
https://github.com/ipmitool/ipmitool/security/advisories/GHSA-g659-9qxw-p7cp
|
|
|
|
The `read_fru_area_section` function only performs size validation of
|
|
requested read size, and falsely assumes that the IPMI message will not
|
|
respond with more than the requested amount of data; it uses the
|
|
unvalidated response size to copy into `frubuf`. If the response is
|
|
larger than the request, this can result in overflowing the buffer.
|
|
|
|
The same issue affects the `read_fru_area` function.
|
|
---
|
|
lib/ipmi_fru.c | 33 +++++++++++++++++++++++++++++++--
|
|
1 file changed, 31 insertions(+), 2 deletions(-)
|
|
|
|
--- a/lib/ipmi_fru.c
|
|
+++ b/lib/ipmi_fru.c
|
|
@@ -615,7 +615,10 @@ int
|
|
read_fru_area(struct ipmi_intf * intf, struct fru_info *fru, uint8_t id,
|
|
uint32_t offset, uint32_t length, uint8_t *frubuf)
|
|
{
|
|
- uint32_t off = offset, tmp, finish;
|
|
+ uint32_t off = offset;
|
|
+ uint32_t tmp;
|
|
+ uint32_t finish;
|
|
+ uint32_t size_left_in_buffer;
|
|
struct ipmi_rs * rsp;
|
|
struct ipmi_rq req;
|
|
uint8_t msg_data[4];
|
|
@@ -628,10 +631,12 @@ read_fru_area(struct ipmi_intf * intf, s
|
|
|
|
finish = offset + length;
|
|
if (finish > fru->size) {
|
|
+ memset(frubuf + fru->size, 0, length - fru->size);
|
|
finish = fru->size;
|
|
lprintf(LOG_NOTICE, "Read FRU Area length %d too large, "
|
|
"Adjusting to %d",
|
|
offset + length, finish - offset);
|
|
+ length = finish - offset;
|
|
}
|
|
|
|
memset(&req, 0, sizeof(req));
|
|
@@ -667,6 +672,7 @@ read_fru_area(struct ipmi_intf * intf, s
|
|
}
|
|
}
|
|
|
|
+ size_left_in_buffer = length;
|
|
do {
|
|
tmp = fru->access ? off >> 1 : off;
|
|
msg_data[0] = id;
|
|
@@ -707,9 +713,18 @@ read_fru_area(struct ipmi_intf * intf, s
|
|
}
|
|
|
|
tmp = fru->access ? rsp->data[0] << 1 : rsp->data[0];
|
|
+ if(rsp->data_len < 1
|
|
+ || tmp > rsp->data_len - 1
|
|
+ || tmp > size_left_in_buffer)
|
|
+ {
|
|
+ printf(" Not enough buffer size");
|
|
+ return -1;
|
|
+ }
|
|
+
|
|
memcpy(frubuf, rsp->data + 1, tmp);
|
|
off += tmp;
|
|
frubuf += tmp;
|
|
+ size_left_in_buffer -= tmp;
|
|
/* sometimes the size returned in the Info command
|
|
* is too large. return 0 so higher level function
|
|
* still attempts to parse what was returned */
|
|
@@ -742,7 +757,9 @@ read_fru_area_section(struct ipmi_intf *
|
|
uint32_t offset, uint32_t length, uint8_t *frubuf)
|
|
{
|
|
static uint32_t fru_data_rqst_size = 20;
|
|
- uint32_t off = offset, tmp, finish;
|
|
+ uint32_t off = offset;
|
|
+ uint32_t tmp, finish;
|
|
+ uint32_t size_left_in_buffer;
|
|
struct ipmi_rs * rsp;
|
|
struct ipmi_rq req;
|
|
uint8_t msg_data[4];
|
|
@@ -755,10 +772,12 @@ read_fru_area_section(struct ipmi_intf *
|
|
|
|
finish = offset + length;
|
|
if (finish > fru->size) {
|
|
+ memset(frubuf + fru->size, 0, length - fru->size);
|
|
finish = fru->size;
|
|
lprintf(LOG_NOTICE, "Read FRU Area length %d too large, "
|
|
"Adjusting to %d",
|
|
offset + length, finish - offset);
|
|
+ length = finish - offset;
|
|
}
|
|
|
|
memset(&req, 0, sizeof(req));
|
|
@@ -773,6 +792,8 @@ read_fru_area_section(struct ipmi_intf *
|
|
if (fru->access && fru_data_rqst_size > 16)
|
|
#endif
|
|
fru_data_rqst_size = 16;
|
|
+
|
|
+ size_left_in_buffer = length;
|
|
do {
|
|
tmp = fru->access ? off >> 1 : off;
|
|
msg_data[0] = id;
|
|
@@ -804,8 +825,16 @@ read_fru_area_section(struct ipmi_intf *
|
|
}
|
|
|
|
tmp = fru->access ? rsp->data[0] << 1 : rsp->data[0];
|
|
+ if(rsp->data_len < 1
|
|
+ || tmp > rsp->data_len - 1
|
|
+ || tmp > size_left_in_buffer)
|
|
+ {
|
|
+ printf(" Not enough buffer size");
|
|
+ return -1;
|
|
+ }
|
|
memcpy((frubuf + off)-offset, rsp->data + 1, tmp);
|
|
off += tmp;
|
|
+ size_left_in_buffer -= tmp;
|
|
|
|
/* sometimes the size returned in the Info command
|
|
* is too large. return 0 so higher level function
|