Backport of: From 422bec25ae4a1ab03fd4d6f728695ed279173b18 Mon Sep 17 00:00:00 2001 From: "Andrew G. Morgan" Date: Wed, 3 May 2023 19:44:22 -0700 Subject: 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 Upstream-Status: Backport [import from ubuntu https://git.launchpad.net/ubuntu/+source/libcap2/tree/debian/patches/CVE-2023-2603.patch?h=ubuntu/focal-security Upstream commit https://git.kernel.org/pub/scm/libs/libcap/libcap.git/commit/?id=422bec25ae4a1ab03fd4d6f728695ed279173b18] CVE: CVE-2023-2603 Signed-off-by: Vijay Anusuri --- libcap/cap_alloc.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) --- a/libcap/cap_alloc.c +++ b/libcap/cap_alloc.c @@ -76,13 +76,22 @@ 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; + } + len += sizeof(__u32) + 1; + + raw_data = malloc(len); if (raw_data == NULL) { errno = ENOMEM; return NULL;