util-linux/0061-libblkid-probe-fix-size-and-offset-overflows-fuzzing.patch

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From 2fcbf867f00888216f7c4f57161b083ebdc8a836 Mon Sep 17 00:00:00 2001
From: Karel Zak <kzak@redhat.com>
Date: Thu, 2 Jun 2022 16:02:54 +0200
Subject: libblkid: (probe) fix size and offset overflows [fuzzing]
Addresses: https://issues.redhat.com/browse/RHEL-16071
Upstream: http://github.com/util-linux/util-linux/commit/106de261469e1001243d5b81ed895762fb34b2ba
Reported-by: Thibault Guittet <tguittet@redhat.com>
Signed-off-by: Karel Zak <kzak@redhat.com>
---
libblkid/src/probe.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)
diff --git a/libblkid/src/probe.c b/libblkid/src/probe.c
index d317dc19a..c2bcea616 100644
--- a/libblkid/src/probe.c
+++ b/libblkid/src/probe.c
@@ -612,6 +612,11 @@ static int hide_buffer(blkid_probe pr, uint64_t off, uint64_t len)
struct list_head *p;
int ct = 0;
+ if (UINT64_MAX - len < off) {
+ DBG(BUFFER, ul_debug("\t hide-buffer overflow (ignore)"));
+ return -EINVAL;
+ }
+
list_for_each(p, &pr->buffers) {
struct blkid_bufinfo *x =
list_entry(p, struct blkid_bufinfo, bufs);
@@ -647,14 +652,20 @@ unsigned char *blkid_probe_get_buffer(blkid_probe pr, uint64_t off, uint64_t len
DBG(BUFFER, ul_debug("\t>>>> off=%ju, real-off=%ju (probe <%ju..%ju>, len=%ju",
off, real_off, pr->off, pr->off + pr->size, len));
*/
-
if (pr->size == 0) {
errno = EINVAL;
return NULL;
}
- if (len == 0 || (!S_ISCHR(pr->mode) && pr->off + pr->size < real_off + len)) {
- DBG(BUFFER, ul_debug("\t ignore: request out of probing area"));
+ if (UINT64_MAX - len < off || UINT64_MAX - len < real_off) {
+ DBG(BUFFER, ul_debug("\t read-buffer overflow (ignore)"));
+ return NULL;
+ }
+
+ if (len == 0
+ || (!S_ISCHR(pr->mode) && (pr->size < off || pr->size < len))
+ || (!S_ISCHR(pr->mode) && (pr->off + pr->size < real_off + len))) {
+ DBG(BUFFER, ul_debug("\t read-buffer out of probing area (ignore)"));
errno = 0;
return NULL;
}
--
2.43.0