[PATCH 4.9 070/145] 509: fix printing uninitialized stack memory when OID is empty

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

--

From: Eric Biggers 


[ Upstream commit 8dfd2f22d3bf3ab7714f7495ad5d897b8845e8c1 ]

Callers of sprint_oid() do not check its return value before printing
the result.  In the case where the OID is zero-length, -EBADMSG was
being returned without anything being written to the buffer, resulting
in uninitialized stack memory being printed.  Fix this by writing
"(bad)" to the buffer in the cases where -EBADMSG is returned.

Fixes: 4f73175d0375 ("X.509: Add utility functions to render OIDs as strings")
Signed-off-by: Eric Biggers 
Signed-off-by: David Howells 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman 
---
 lib/oid_registry.c |8 ++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/lib/oid_registry.c
+++ b/lib/oid_registry.c
@@ -116,7 +116,7 @@ int sprint_oid(const void *data, size_t
int count;
 
if (v >= end)
-   return -EBADMSG;
+   goto bad;
 
n = *v++;
ret = count = snprintf(buffer, bufsize, "%u.%u", n / 40, n % 40);
@@ -134,7 +134,7 @@ int sprint_oid(const void *data, size_t
num = n & 0x7f;
do {
if (v >= end)
-   return -EBADMSG;
+   goto bad;
n = *v++;
num <<= 7;
num |= n & 0x7f;
@@ -148,6 +148,10 @@ int sprint_oid(const void *data, size_t
}
 
return ret;
+
+bad:
+   snprintf(buffer, bufsize, "(bad)");
+   return -EBADMSG;
 }
 EXPORT_SYMBOL_GPL(sprint_oid);
 

[PATCH 4.9 070/145] 509: fix printing uninitialized stack memory when OID is empty

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

--

From: Eric Biggers 


[ Upstream commit 8dfd2f22d3bf3ab7714f7495ad5d897b8845e8c1 ]

Callers of sprint_oid() do not check its return value before printing
the result.  In the case where the OID is zero-length, -EBADMSG was
being returned without anything being written to the buffer, resulting
in uninitialized stack memory being printed.  Fix this by writing
"(bad)" to the buffer in the cases where -EBADMSG is returned.

Fixes: 4f73175d0375 ("X.509: Add utility functions to render OIDs as strings")
Signed-off-by: Eric Biggers 
Signed-off-by: David Howells 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman 
---
 lib/oid_registry.c |8 ++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/lib/oid_registry.c
+++ b/lib/oid_registry.c
@@ -116,7 +116,7 @@ int sprint_oid(const void *data, size_t
int count;
 
if (v >= end)
-   return -EBADMSG;
+   goto bad;
 
n = *v++;
ret = count = snprintf(buffer, bufsize, "%u.%u", n / 40, n % 40);
@@ -134,7 +134,7 @@ int sprint_oid(const void *data, size_t
num = n & 0x7f;
do {
if (v >= end)
-   return -EBADMSG;
+   goto bad;
n = *v++;
num <<= 7;
num |= n & 0x7f;
@@ -148,6 +148,10 @@ int sprint_oid(const void *data, size_t
}
 
return ret;
+
+bad:
+   snprintf(buffer, bufsize, "(bad)");
+   return -EBADMSG;
 }
 EXPORT_SYMBOL_GPL(sprint_oid);