Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
Eric Biggers
authored
syzkaller with KASAN reported an out-of-bounds read in
asn1_ber_decoder(). It can be reproduced by the following command,
assuming CONFIG_X509_CERTIFICATE_PARSER=y and CONFIG_KASAN=y:
keyctl add asymmetric desc $'\x30\x30' @s
The bug is that the length of an ASN.1 data value isn't validated in the
case where it is encoded using the short form, causing the decoder to
read past the end of the input buffer. Fix it by validating the length.
The bug report was:
BUG: KASAN: slab-out-of-bounds in asn1_ber_decoder+0x10cb/0x1730 lib/asn1_decoder.c:233
Read of size 1 at addr ffff88003cccfa02 by task syz-executor0/6818
CPU: 1 PID: 6818 Comm: syz-executor0 Not tainted 4.14.0-rc7-00008-g5f479447 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:16 [inline]
dump_stack+0xb3/0x10b lib/dump_stack.c:52
print_address_description+0x79/0x2a0 mm/kasan/report...