Re: [PATCHv4 3/4] block/sed: Check received header lengths

[Christoph Hellwig]

On Wed, Feb 15, 2017 at 02:45:56PM -0700, Jon Derrick wrote:
> Add a buffer size check against discovery and response header lengths
> before we loop over their buffers.
> 
> Signed-off-by: Jon Derrick 
> Reviewed-by: Scott Bauer 

Looks fine,

Reviewed-by: Christoph Hellwig 

Re: [PATCHv4 3/4] block/sed: Check received header lengths

[Christoph Hellwig]

On Wed, Feb 15, 2017 at 02:45:56PM -0700, Jon Derrick wrote:
> Add a buffer size check against discovery and response header lengths
> before we loop over their buffers.
> 
> Signed-off-by: Jon Derrick 
> Reviewed-by: Scott Bauer 

Looks fine,

Reviewed-by: Christoph Hellwig 

[PATCHv4 3/4] block/sed: Check received header lengths

[Jon Derrick]

Add a buffer size check against discovery and response header lengths
before we loop over their buffers.

Signed-off-by: Jon Derrick 
Reviewed-by: Scott Bauer 
---
 block/sed-opal.c | 35 +--
 1 file changed, 21 insertions(+), 14 deletions(-)

diff --git a/block/sed-opal.c b/block/sed-opal.c
index 00673cf..383d5d6 100644
--- a/block/sed-opal.c
+++ b/block/sed-opal.c
@@ -340,10 +340,17 @@ static int opal_discovery0_end(struct opal_dev *dev)
const struct d0_header *hdr = (struct d0_header *)dev->resp;
const u8 *epos = dev->resp, *cpos = dev->resp;
u16 comid = 0;
+   u32 hlen = be32_to_cpu(hdr->length);
 
-   print_buffer(dev->resp, be32_to_cpu(hdr->length));
+   print_buffer(dev->resp, hlen);
 
-   epos += be32_to_cpu(hdr->length); /* end of buffer */
+   if (hlen > IO_BUFFER_LENGTH - sizeof(*hdr)) {
+   pr_warn("Discovery length overflows buffer (%zu+%u)/%u\n",
+   sizeof(*hdr), hlen, IO_BUFFER_LENGTH);
+   return -EFAULT;
+   }
+
+   epos += hlen; /* end of buffer */
cpos += sizeof(*hdr); /* current position on buffer */
 
while (cpos < epos && supported) {
@@ -713,6 +720,7 @@ static int response_parse(const u8 *buf, size_t length,
int total;
ssize_t token_length;
const u8 *pos;
+   u32 clen, plen, slen;
 
if (!buf)
return -EFAULT;
@@ -724,17 +732,16 @@ static int response_parse(const u8 *buf, size_t length,
pos = buf;
pos += sizeof(*hdr);
 
-   pr_debug("Response size: cp: %d, pkt: %d, subpkt: %d\n",
-be32_to_cpu(hdr->cp.length),
-be32_to_cpu(hdr->pkt.length),
-be32_to_cpu(hdr->subpkt.length));
-
-   if (hdr->cp.length == 0 || hdr->pkt.length == 0 ||
-   hdr->subpkt.length == 0) {
-   pr_err("Bad header length. cp: %d, pkt: %d, subpkt: %d\n",
-  be32_to_cpu(hdr->cp.length),
-  be32_to_cpu(hdr->pkt.length),
-  be32_to_cpu(hdr->subpkt.length));
+   clen = be32_to_cpu(hdr->cp.length);
+   plen = be32_to_cpu(hdr->pkt.length);
+   slen = be32_to_cpu(hdr->subpkt.length);
+   pr_debug("Response size: cp: %u, pkt: %u, subpkt: %u\n",
+clen, plen, slen);
+
+   if (clen == 0 || plen == 0 || slen == 0 ||
+   slen > IO_BUFFER_LENGTH - sizeof(*hdr)) {
+   pr_err("Bad header length. cp: %u, pkt: %u, subpkt: %u\n",
+  clen, plen, slen);
print_buffer(pos, sizeof(*hdr));
return -EINVAL;
}
@@ -743,7 +750,7 @@ static int response_parse(const u8 *buf, size_t length,
return -EFAULT;
 
iter = resp->toks;
-   total = be32_to_cpu(hdr->subpkt.length);
+   total = slen;
print_buffer(pos, total);
while (total > 0) {
if (pos[0] <= TINY_ATOM_BYTE) /* tiny atom */
-- 
1.8.3.1

[PATCHv4 3/4] block/sed: Check received header lengths

[Jon Derrick]

Add a buffer size check against discovery and response header lengths
before we loop over their buffers.

Signed-off-by: Jon Derrick 
Reviewed-by: Scott Bauer 
---
 block/sed-opal.c | 35 +--
 1 file changed, 21 insertions(+), 14 deletions(-)

diff --git a/block/sed-opal.c b/block/sed-opal.c
index 00673cf..383d5d6 100644
--- a/block/sed-opal.c
+++ b/block/sed-opal.c
@@ -340,10 +340,17 @@ static int opal_discovery0_end(struct opal_dev *dev)
const struct d0_header *hdr = (struct d0_header *)dev->resp;
const u8 *epos = dev->resp, *cpos = dev->resp;
u16 comid = 0;
+   u32 hlen = be32_to_cpu(hdr->length);
 
-   print_buffer(dev->resp, be32_to_cpu(hdr->length));
+   print_buffer(dev->resp, hlen);
 
-   epos += be32_to_cpu(hdr->length); /* end of buffer */
+   if (hlen > IO_BUFFER_LENGTH - sizeof(*hdr)) {
+   pr_warn("Discovery length overflows buffer (%zu+%u)/%u\n",
+   sizeof(*hdr), hlen, IO_BUFFER_LENGTH);
+   return -EFAULT;
+   }
+
+   epos += hlen; /* end of buffer */
cpos += sizeof(*hdr); /* current position on buffer */
 
while (cpos < epos && supported) {
@@ -713,6 +720,7 @@ static int response_parse(const u8 *buf, size_t length,
int total;
ssize_t token_length;
const u8 *pos;
+   u32 clen, plen, slen;
 
if (!buf)
return -EFAULT;
@@ -724,17 +732,16 @@ static int response_parse(const u8 *buf, size_t length,
pos = buf;
pos += sizeof(*hdr);
 
-   pr_debug("Response size: cp: %d, pkt: %d, subpkt: %d\n",
-be32_to_cpu(hdr->cp.length),
-be32_to_cpu(hdr->pkt.length),
-be32_to_cpu(hdr->subpkt.length));
-
-   if (hdr->cp.length == 0 || hdr->pkt.length == 0 ||
-   hdr->subpkt.length == 0) {
-   pr_err("Bad header length. cp: %d, pkt: %d, subpkt: %d\n",
-  be32_to_cpu(hdr->cp.length),
-  be32_to_cpu(hdr->pkt.length),
-  be32_to_cpu(hdr->subpkt.length));
+   clen = be32_to_cpu(hdr->cp.length);
+   plen = be32_to_cpu(hdr->pkt.length);
+   slen = be32_to_cpu(hdr->subpkt.length);
+   pr_debug("Response size: cp: %u, pkt: %u, subpkt: %u\n",
+clen, plen, slen);
+
+   if (clen == 0 || plen == 0 || slen == 0 ||
+   slen > IO_BUFFER_LENGTH - sizeof(*hdr)) {
+   pr_err("Bad header length. cp: %u, pkt: %u, subpkt: %u\n",
+  clen, plen, slen);
print_buffer(pos, sizeof(*hdr));
return -EINVAL;
}
@@ -743,7 +750,7 @@ static int response_parse(const u8 *buf, size_t length,
return -EFAULT;
 
iter = resp->toks;
-   total = be32_to_cpu(hdr->subpkt.length);
+   total = slen;
print_buffer(pos, total);
while (total > 0) {
if (pos[0] <= TINY_ATOM_BYTE) /* tiny atom */
-- 
1.8.3.1