From: Eric Biggers ebiggers3@gmail.com
This patch has been added to the 4.1 stable tree. If you have any objections, please let us know.
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[ 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 ebiggers@google.com Signed-off-by: David Howells dhowells@redhat.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- lib/oid_registry.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/lib/oid_registry.c b/lib/oid_registry.c index 318f382a010d..150e04d70303 100644 --- a/lib/oid_registry.c +++ b/lib/oid_registry.c @@ -116,7 +116,7 @@ int sprint_oid(const void *data, size_t datasize, char *buffer, size_t bufsize) 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 datasize, char *buffer, size_t bufsize) 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 datasize, char *buffer, size_t bufsize) }
return ret; + +bad: + snprintf(buffer, bufsize, "(bad)"); + return -EBADMSG; } EXPORT_SYMBOL_GPL(sprint_oid);