e5e24107f9
cbfs_get_handle() and cbfs_get_attr() are both looping over elements to find a particular one. Each element header contains the element's length, which is used to compute the next element's offset. Invalid or corrupted CBFS files could lead to infinite loops where the offset would remain constant across iterations, due to 0-length elements or integer overflows in the computation of the next offset. This patch makes both functions more robust by adding a check that ensure offsets are strictly monotonic. Instead of infinite looping, the functions are now printing an ERROR and returning a NULL value. Change-Id: I440e82fa969b8c2aacc5800e7e26450c3b97c74a Signed-off-by: Alex Rebert <alexandre.rebert@gmail.com> Found-by: Mayhem Reviewed-on: https://review.coreboot.org/c/coreboot/+/39177 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net> Reviewed-by: Patrick Georgi <pgeorgi@google.com> |
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.. | ||
arch | ||
bin | ||
configs | ||
crypto | ||
curses | ||
drivers | ||
gdb | ||
include | ||
libc | ||
libcbfs | ||
liblz4 | ||
liblzma | ||
libpci | ||
sample | ||
tests | ||
Doxyfile | ||
Kconfig | ||
LICENSE_GPL | ||
LICENSES | ||
Makefile | ||
Makefile.inc | ||
README |
------------------------------------------------------------------------------- libpayload README ------------------------------------------------------------------------------- libpayload is a minimal library to support standalone payloads that can be booted with firmware like coreboot. It handles the setup code, and provides common C library symbols such as malloc() and printf(). Note: This is _not_ a standard library for use with an operating system, rather it's only useful for coreboot payload development! See https://www.coreboot.org for details on coreboot. Installation ------------ $ git clone https://review.coreboot.org/coreboot.git $ cd coreboot/payloads/libpayload $ make menuconfig $ make $ make install (optional, will install into ./install per default) On x86 systems, libpayload will always be 32-bit even if your host OS runs in 64-bit, so you might have to install the 32-bit libgcc version. On Debian systems you'd do 'apt-get install gcc-multilib' for example. Run 'make distclean' before switching boards. This command will remove your current .config file, so you need 'make menuconfig' again or 'make defconfig' in order to set up configuration. Default configuration is based on 'configs/defconfig'. See the configs/ directory for examples of configuration. Usage ----- Here's an example of a very simple payload (hello.c) and how to build it: #include <libpayload.h> int main(void) { printf("Hello, world!\n"); return 0; } Building the payload using the 'lpgcc' compiler wrapper: $ lpgcc -o hello.elf hello.c Please see the sample/ directory for details. Website and Mailing List ------------------------ The main website is https://www.coreboot.org/Libpayload. For additional information, patches, and discussions, please join the coreboot mailing list at https://www.coreboot.org/Mailinglist, where most libpayload developers are subscribed. Copyright and License --------------------- See LICENSES.