From db29a01c413fcaaa1095284dfe31582e97d35679 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Wed, 28 Apr 2021 19:46:47 +0200 Subject: [PATCH] cpio: Fix possible crash on 64-bit systems copyin_link() tries to allocate (unsigned int)c_filesize + 1 bytes. If c_filesize == UINT_MAX, this works out as 0 bytes, resulting in a null pointer and a subsequent SIGSEGV. The previous commit made this impossible on 32-bit systems. CVE-2021-31871 CVE: CVE-2021-31871 Upstream-Status: Backport [https://git.kernel.org/pub/scm/libs/klibc/klibc.git/commit/?id=2e48a12ab1e30d43498c2d53e878a11a1b5102d5] Signed-off-by: Ben Hutchings --- usr/utils/cpio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/usr/utils/cpio.c b/usr/utils/cpio.c index cb61679..a13c876 100644 --- a/usr/utils/cpio.c +++ b/usr/utils/cpio.c @@ -831,7 +831,7 @@ static void copyin_link(struct new_cpio_header *file_hdr, int in_file_des) char *link_name = NULL; /* Name of hard and symbolic links. */ int res; /* Result of various function calls. */ - link_name = (char *)xmalloc((unsigned int)file_hdr->c_filesize + 1); + link_name = (char *)xmalloc(file_hdr->c_filesize + 1); link_name[file_hdr->c_filesize] = '\0'; tape_buffered_read(link_name, in_file_des, file_hdr->c_filesize); tape_skip_padding(in_file_des, file_hdr->c_filesize);