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 [https://git.kernel.org/pub/scm/libs/libcap/libcap.git/commit/?id=422bec25ae4a1ab03fd4d6f728695ed279173b18] CVE: CVE-2023-2603 Signed-off-by: Vivek Kumbhar --- libcap/cap_alloc.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/libcap/cap_alloc.c b/libcap/cap_alloc.c index c826e7a..25f9981 100644 --- a/libcap/cap_alloc.c +++ b/libcap/cap_alloc.c @@ -105,15 +105,17 @@ char *_libcap_strdup(const char *old) errno = EINVAL; return NULL; } - len = strlen(old) + 1 + 2*sizeof(__u32); - if (len < sizeof(struct _cap_alloc_s)) { - len = sizeof(struct _cap_alloc_s); - } - if ((len & 0xffffffff) != len) { + + len = strlen(old); + if ((len & 0x3fffffff) != len) { _cap_debug("len is too long for libcap to manage"); errno = EINVAL; return NULL; } + len += 1 + 2*sizeof(__u32); + if (len < sizeof(struct _cap_alloc_s)) { + len = sizeof(struct _cap_alloc_s); + } raw_data = calloc(1, len); if (raw_data == NULL) { -- 2.25.1