samba/backport-utils-asn1-avoid-undefined-behaviour.patch
eaglegai edc1f6e252 backport fo fix fuzz error:
idl: drsuapi_DsaAddressListItem_V1 limit recursion
idl: limit recurion on recursive-elements
lib: ldb Limit depth of ldb_parse_tree
librpc: ndr add recursion check macros
librpc: ndr Heap-buffer-overflow in lzxpress_decompress
librpc: ndr NDR_PULL_ALIGN check for unsigned overflow
lzxpress: add bounds checking to lzxpress decompress
lzxpress: avoid technically undefined shift
pidl: Add recursive depth checks
utils: asn1 avoid undefined behaviour
witness: idl fix length calculation for witness_IPaddrInfoList
2021-10-29 10:40:24 +08:00

39 lines
1.2 KiB
Diff

From ed9abf94b3167a1a61b5da163e9b07b06c8a457b Mon Sep 17 00:00:00 2001
From: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
Date: Sun, 6 Sep 2020 09:35:49 +1200
Subject: [PATCH] utils/asn1: avoid undefined behaviour warning
UBSAN does not like an int >= 1<<24 being shifted left.
We check the overflow in the very next line.
Credit to OSS-Fuzz.
REF: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=25436
Signed-off-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Autobuild-User(master): Andrew Bartlett <abartlet@samba.org>
Autobuild-Date(master): Fri Sep 11 05:05:59 UTC 2020 on sn-devel-184
---
lib/util/asn1.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/lib/util/asn1.c b/lib/util/asn1.c
index 6b1b4bc2877f..9ab9e1b08449 100644
--- a/lib/util/asn1.c
+++ b/lib/util/asn1.c
@@ -1071,7 +1071,11 @@ bool asn1_read_enumerated(struct asn1_data *data, int *v)
if (!asn1_read_uint8(data, &b)) {
return false;
}
- *v = (*v << 8) + b;
+ /*
+ * To please/fool the Undefined Behaviour Sanitizer we cast to
+ * unsigned for the left shift.
+ */
+ *v = ((unsigned int)*v << 8) + b;
}
return asn1_end_tag(data);
}