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Yonghong Song 12e6196fb1 selftests/bpf: Test bpf_iter buffer access with negative offset
Commit afbf21dce6 ("bpf: Support readonly/readwrite buffers
in verifier") added readonly/readwrite buffer support which
is currently used by bpf_iter tracing programs. It has
a bug with incorrect parameter ordering which later fixed
by Commit f6dfbe31e8 ("bpf: Fix swapped arguments in calls
to check_buffer_access").

This patch added a test case with a negative offset access
which will trigger the error path.

Without Commit f6dfbe31e8, running the test case in the patch,
the error message looks like:
   R1_w=rdwr_buf(id=0,off=0,imm=0) R10=fp0
  ; value_sum += *(__u32 *)(value - 4);
  2: (61) r1 = *(u32 *)(r1 -4)
  R1 invalid (null) buffer access: off=-4, size=4

With the above commit, the error message looks like:
   R1_w=rdwr_buf(id=0,off=0,imm=0) R10=fp0
  ; value_sum += *(__u32 *)(value - 4);
  2: (61) r1 = *(u32 *)(r1 -4)
  R1 invalid rdwr buffer access: off=-4, size=4

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200728221801.1090406-1-yhs@fb.com
2020-07-31 00:43:49 +02:00
Documentation Documentation/bpf: Document CGROUP_STORAGE map type 2020-07-25 20:16:36 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
arch bpf, arm64: Add BPF exception tables 2020-07-31 00:43:40 +02:00
block block-5.8-2020-07-10 2020-07-10 09:55:46 -07:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-07-25 17:49:04 -07:00
drivers bpf, xdp: Remove XDP_QUERY_PROG and XDP_QUERY_PROG_HW XDP commands 2020-07-25 20:37:02 -07:00
fs bpf: Refactor to provide aux info to bpf_iter_init_seq_priv_t 2020-07-25 20:16:32 -07:00
include bpf: Fix bpf_ringbuf_output() signature to return long 2020-07-28 12:20:44 +02:00
init kbuild: fix CONFIG_CC_CAN_LINK(_STATIC) for cross-compilation with Clang 2020-07-02 00:57:45 +09:00
ipc mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
kernel bpf: Add missing newline characters in verifier error messages 2020-07-31 00:43:49 +02:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-07-25 17:49:04 -07:00
mm Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-07-25 17:49:04 -07:00
net xdp: Prevent kernel-infoleak in xsk_getsockopt() 2020-07-28 12:50:15 +02:00
samples samples/bpf, selftests/bpf: Use bpf_probe_read_kernel 2020-07-21 13:26:26 -07:00
scripts Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-07-25 17:49:04 -07:00
security integrity/ima: switch to using __kernel_read 2020-07-08 08:27:57 +02:00
sound sound fixes for 5.8-rc7 2020-07-21 08:06:45 -07:00
tools selftests/bpf: Test bpf_iter buffer access with negative offset 2020-07-31 00:43:49 +02:00
usr bpfilter: match bit size of bpfilter_umh to that of the kernel 2020-05-17 18:52:01 +09:00
virt kvm: use more precise cast and do not drop __user 2020-07-02 05:39:31 -04:00
.clang-format block: add bio_for_each_bvec_all() 2020-05-25 11:25:24 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: Do not track `defconfig` from `make savedefconfig` 2020-07-05 16:15:46 +09:00
.mailmap mailmap: add entry for Mike Rapoport 2020-07-24 12:42:41 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS mailmap: change email for Ricardo Ribalda 2020-05-25 18:59:59 -06:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-07-25 17:49:04 -07:00
Makefile Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-07-25 17:49:04 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

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.