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| author | Eric Biggers <ebiggers3@gmail.com> | 2017-12-08 15:13:28 +0000 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2017-12-08 15:13:28 +0000 |
| commit | 8dfd2f22d3bf3ab7714f7495ad5d897b8845e8c1 (patch) | |
| tree | c937db5e51b0f6404d53cb4044e83b8071a8cc51 /lib/oid_registry.c | |
| parent | 47e0a208fb9d91e3f3c86309e752b13a36470ae8 (diff) | |
| download | lwn-8dfd2f22d3bf3ab7714f7495ad5d897b8845e8c1.tar.gz lwn-8dfd2f22d3bf3ab7714f7495ad5d897b8845e8c1.zip | |
509: fix printing uninitialized stack memory when OID is empty
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>
Diffstat (limited to 'lib/oid_registry.c')
| -rw-r--r-- | lib/oid_registry.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/lib/oid_registry.c b/lib/oid_registry.c index 5a75d127995d..0bcac6ccb1b2 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); |