From 6d05fb3ea772c3642624ec6e0fb4e8d099bcdb8e Mon Sep 17 00:00:00 2001
From: Gary Lockyer <gary@catalyst.net.nz>
Date: Wed, 22 Jan 2020 14:16:02 +1300
Subject: [PATCH] librpc ndr: NDR_PULL_ALIGN check for unsigned overflow
Handle uint32 overflow in NDR_PULL_ALIGN
Credit to OSS-Fuzz
REF: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=20083
BUG: https://bugzilla.samba.org/show_bug.cgi?id=14236
Signed-off-by: Gary Lockyer <gary@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
---
librpc/ndr/libndr.h | 7 +++++++
selftest/knownfail.d/bug-14236 | 1 -
2 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/librpc/ndr/libndr.h b/librpc/ndr/libndr.h
index b7cccf3dfc5..c2c7e263049 100644
--- a/librpc/ndr/libndr.h
+++ b/librpc/ndr/libndr.h
@@ -331,6 +331,13 @@ enum ndr_compression_alg {
if (unlikely(ndr->flags & LIBNDR_FLAG_PAD_CHECK)) { \
ndr_check_padding(ndr, n); \
} \
+ if(unlikely( \
+ ((ndr->offset + (n-1)) & (~(n-1))) < ndr->offset)) {\
+ return ndr_pull_error( \
+ ndr, \
+ NDR_ERR_BUFSIZE, \
+ "Pull align (overflow) %u", (unsigned)n); \
+ } \
ndr->offset = (ndr->offset + (n-1)) & ~(n-1); \
} \
if (unlikely(ndr->offset > ndr->data_size)) { \
--
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