From e362c60eb89c923acda7efd4a23ca6d4df1cf965 Mon Sep 17 00:00:00 2001 From: yunjia_w Date: Wed, 31 May 2023 11:34:54 +0800 Subject: [PATCH] Large strings can confuse libcap's internal strdup code. Avoid something subtle with really long strings: 1073741823 should be enough for anybody. This is an improved fix over something attempted in libcap-2.55 to address some static analysis findings. Reviewing the library, cap_proc_root() and cap_launcher_set_chroot() are the only two calls where the library is potentially exposed to a user controlled string input. Credit for finding this bug in libcap goes to Richard Weinberger of X41 D-Sec GmbH (https://x41-dsec.de/) who performed a security audit of the libcap source code in April of 2023. The audit was sponsored by the Open Source Technology Improvement Fund (https://ostif.org/). Audit ref: LCAP-CR-23-02 (CVE-2023-2603) Signed-off-by: Andrew G. Morgan Signed-off-by: wangyunjia --- libcap/cap_alloc.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/libcap/cap_alloc.c b/libcap/cap_alloc.c index 57991a5..0849808 100644 --- a/libcap/cap_alloc.c +++ b/libcap/cap_alloc.c @@ -76,13 +76,20 @@ cap_t cap_init(void) char *_libcap_strdup(const char *old) { __u32 *raw_data; + size_t len; if (old == NULL) { errno = EINVAL; return NULL; } - raw_data = malloc( sizeof(__u32) + strlen(old) + 1 ); + len = strlen(old); + if ((len & 0x3fffffff) != len) { + _cap_debug("len is too long for libcap to manage"); + errno = EINVAL; + return NULL; + } + raw_data = malloc( sizeof(__u32) + len + 1 ); if (raw_data == NULL) { errno = ENOMEM; return NULL; -- 2.27.0