mirror of
https://github.com/openwrt/openwrt.git
synced 2025-01-28 15:14:11 +00:00
78c4c04dd7
This packports two security fixes from master. Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de> (cherry picked from commit f9005d4f80dee3dcc257d4613cbc46668faad094)
105 lines
3.5 KiB
Diff
105 lines
3.5 KiB
Diff
From eae126f66663e5c73e5d290b8e3134449489340f Mon Sep 17 00:00:00 2001
|
|
From: Hauke Mehrtens <hauke@hauke-m.de>
|
|
Date: Sun, 4 Oct 2020 17:14:49 +0200
|
|
Subject: [PATCH] file: Check buffer size after strtok()
|
|
MIME-Version: 1.0
|
|
Content-Type: text/plain; charset=UTF-8
|
|
Content-Transfer-Encoding: 8bit
|
|
|
|
This fixes a heap overflow in the parsing of the uci line.
|
|
|
|
The line which is parsed and put into pctx->buf is null terminated and
|
|
stored on the heap. In the uci_parse_line() function we use strtok() to
|
|
split this string in multiple parts after divided by a space or tab.
|
|
strtok() replaces these characters with a NULL byte. If the next byte is
|
|
NULL we assume that this NULL byte was added by strtok() and try to
|
|
parse the string after this NULL byte. If this NULL byte was not added
|
|
by strtok(), but by fgets() to mark the end of the string we would read
|
|
over this end of the string in uninitialized memory and later over the
|
|
allocated buffer.
|
|
|
|
Fix this problem by storing how long the line we read was and check if
|
|
we would read over the end of the string here.
|
|
|
|
This also adds the input which detected this crash to the corpus of the
|
|
fuzzer.
|
|
|
|
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
|
|
[fixed merge conflict in tests]
|
|
Signed-off-by: Petr Štetiar <ynezz@true.cz>
|
|
---
|
|
file.c | 19 ++++++++++++++++---
|
|
tests/cram/test-san_uci_import.t | 1 +
|
|
tests/cram/test_uci_import.t | 1 +
|
|
.../2e18ecc3a759dedc9357b1298e9269eccc5c5a6b | 1 +
|
|
uci_internal.h | 1 +
|
|
5 files changed, 20 insertions(+), 3 deletions(-)
|
|
create mode 100644 tests/fuzz/corpus/2e18ecc3a759dedc9357b1298e9269eccc5c5a6b
|
|
|
|
--- a/file.c
|
|
+++ b/file.c
|
|
@@ -64,6 +64,7 @@ __private void uci_getln(struct uci_cont
|
|
return;
|
|
|
|
ofs += strlen(p);
|
|
+ pctx->buf_filled = ofs;
|
|
if (pctx->buf[ofs - 1] == '\n') {
|
|
pctx->line++;
|
|
return;
|
|
@@ -121,6 +122,15 @@ static inline void addc(struct uci_conte
|
|
*pos_src += 1;
|
|
}
|
|
|
|
+static int uci_increase_pos(struct uci_parse_context *pctx, size_t add)
|
|
+{
|
|
+ if (pctx->pos + add > pctx->buf_filled)
|
|
+ return -EINVAL;
|
|
+
|
|
+ pctx->pos += add;
|
|
+ return 0;
|
|
+}
|
|
+
|
|
/*
|
|
* parse a double quoted string argument from the command line
|
|
*/
|
|
@@ -385,7 +395,8 @@ static void uci_parse_package(struct uci
|
|
char *name;
|
|
|
|
/* command string null-terminated by strtok */
|
|
- pctx->pos += strlen(pctx_cur_str(pctx)) + 1;
|
|
+ if (uci_increase_pos(pctx, strlen(pctx_cur_str(pctx)) + 1))
|
|
+ uci_parse_error(ctx, "package without name");
|
|
|
|
ofs_name = next_arg(ctx, true, true, true);
|
|
assert_eol(ctx);
|
|
@@ -417,7 +428,8 @@ static void uci_parse_config(struct uci_
|
|
}
|
|
|
|
/* command string null-terminated by strtok */
|
|
- pctx->pos += strlen(pctx_cur_str(pctx)) + 1;
|
|
+ if (uci_increase_pos(pctx, strlen(pctx_cur_str(pctx)) + 1))
|
|
+ uci_parse_error(ctx, "config without name");
|
|
|
|
ofs_type = next_arg(ctx, true, false, false);
|
|
type = pctx_str(pctx, ofs_type);
|
|
@@ -467,7 +479,8 @@ static void uci_parse_option(struct uci_
|
|
uci_parse_error(ctx, "option/list command found before the first section");
|
|
|
|
/* command string null-terminated by strtok */
|
|
- pctx->pos += strlen(pctx_cur_str(pctx)) + 1;
|
|
+ if (uci_increase_pos(pctx, strlen(pctx_cur_str(pctx)) + 1))
|
|
+ uci_parse_error(ctx, "option without name");
|
|
|
|
ofs_name = next_arg(ctx, true, true, false);
|
|
ofs_value = next_arg(ctx, false, false, false);
|
|
--- a/uci_internal.h
|
|
+++ b/uci_internal.h
|
|
@@ -33,6 +33,7 @@ struct uci_parse_context
|
|
const char *name;
|
|
char *buf;
|
|
int bufsz;
|
|
+ size_t buf_filled;
|
|
int pos;
|
|
};
|
|
#define pctx_pos(pctx) ((pctx)->pos)
|