libselinux/backport-libselinux-correctly-hash-specfiles-larger-than-4G.patch
zgzxx 990a13251e backport upstream patches
(cherry picked from commit a7bf1057839c82d554d24c1220ddc1609098b96c)
2023-06-13 19:18:19 +08:00

78 lines
2.7 KiB
Diff

From e17619792fa1e342c7f0a819077129adff438cd1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20G=C3=B6ttsche?= <cgzones@googlemail.com>
Date: Wed, 13 Apr 2022 17:56:33 +0200
Subject: [PATCH] libselinux: correctly hash specfiles larger than 4G
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
The internal Sha1Update() functions only handles buffers up to a size of
UINT32_MAX, due to its usage of the type uint32_t. This causes issues
when processing more than UINT32_MAX bytes, e.g. with a specfile larger
than 4G. 0aa974a4 ("libselinux: limit has buffer size") tried to
address this issue, but failed since the overflow check
if (digest->hashbuf_size + buf_len < digest->hashbuf_size) {
will be done in the widest common type, which is size_t, the type of
`buf_len`.
Revert the type of `hashbuf_size` to size_t and instead process the data
in blocks of supported size.
Acked-by: James Carter <jwcart2@gmail.com>
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Reverts: 0aa974a4 ("libselinux: limit has buffer size")
---
libselinux/src/label_internal.h | 2 +-
libselinux/src/label_support.c | 14 +++++++++++++-
2 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/src/label_internal.h b/src/label_internal.h
index 82a762f7..782c6aa8 100644
--- a/src/label_internal.h
+++ b/src/label_internal.h
@@ -57,7 +57,7 @@ int selabel_service_init(struct selabel_handle *rec,
struct selabel_digest {
unsigned char *digest; /* SHA1 digest of specfiles */
unsigned char *hashbuf; /* buffer to hold specfiles */
- uint32_t hashbuf_size; /* buffer size */
+ size_t hashbuf_size; /* buffer size */
size_t specfile_cnt; /* how many specfiles processed */
char **specfile_list; /* and their names */
};
diff --git a/src/label_support.c b/src/label_support.c
index 94ed6e42..54fd49a5 100644
--- a/src/label_support.c
+++ b/src/label_support.c
@@ -116,13 +116,25 @@ int read_spec_entries(char *line_buf, const char **errbuf, int num_args, ...)
void digest_gen_hash(struct selabel_digest *digest)
{
Sha1Context context;
+ size_t remaining_size;
+ const unsigned char *ptr;
/* If SELABEL_OPT_DIGEST not set then just return */
if (!digest)
return;
Sha1Initialise(&context);
- Sha1Update(&context, digest->hashbuf, digest->hashbuf_size);
+
+ /* Process in blocks of UINT32_MAX bytes */
+ remaining_size = digest->hashbuf_size;
+ ptr = digest->hashbuf;
+ while (remaining_size > UINT32_MAX) {
+ Sha1Update(&context, ptr, UINT32_MAX);
+ remaining_size -= UINT32_MAX;
+ ptr += UINT32_MAX;
+ }
+ Sha1Update(&context, ptr, remaining_size);
+
Sha1Finalise(&context, (SHA1_HASH *)digest->digest);
free(digest->hashbuf);
digest->hashbuf = NULL;
--
2.27.0