No description
  • C 96.8%
  • Assembly 0.9%
  • Rust 0.7%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Tao Lyu b0e66977dc bpf: Fix narrow scalar spill onto 64-bit spilled scalar slots
When CAP_PERFMON and CAP_SYS_ADMIN (allow_ptr_leaks) are disabled, the
verifier aims to reject partial overwrite on an 8-byte stack slot that
contains a spilled pointer.

However, in such a scenario, it rejects all partial stack overwrites as
long as the targeted stack slot is a spilled register, because it does
not check if the stack slot is a spilled pointer.

Incomplete checks will result in the rejection of valid programs, which
spill narrower scalar values onto scalar slots, as shown below.

0: R1=ctx() R10=fp0
; asm volatile ( @ repro.bpf.c:679
0: (7a) *(u64 *)(r10 -8) = 1          ; R10=fp0 fp-8_w=1
1: (62) *(u32 *)(r10 -8) = 1
attempt to corrupt spilled pointer on stack
processed 2 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0.

Fix this by expanding the check to not consider spilled scalar registers
when rejecting the write into the stack.

Previous discussion on this patch is at link [0].

  [0]: https://lore.kernel.org/bpf/20240403202409.2615469-1-tao.lyu@epfl.ch

Fixes: ab125ed3ec ("bpf: fix check for attempt to corrupt spilled pointer")
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Tao Lyu <tao.lyu@epfl.ch>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20241204044757.1483141-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
History 2024-12-04 09:19:50 -08:00
arch The biggest change here is eliminating the awful idea that KVM had, of 2024-11-23 16:00:50 -08:00
block for-6.13/block-20241118 2024-11-18 16:50:08 -08:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto Random number generator updates for Linux 6.13-rc1. 2024-11-19 10:43:44 -08:00
Documentation The biggest change here is eliminating the awful idea that KVM had, of 2024-11-23 16:00:50 -08:00
drivers The biggest change here is eliminating the awful idea that KVM had, of 2024-11-23 16:00:50 -08:00
fs - The series "zram: optimal post-processing target selection" from 2024-11-23 09:58:07 -08:00
include The biggest change here is eliminating the awful idea that KVM had, of 2024-11-23 16:00:50 -08:00
init tracing updates for v6.13: 2024-11-22 13:27:01 -08:00
io_uring A rather large update for timekeeping and timers: 2024-11-19 16:35:06 -08:00
ipc fdget(), more trivial conversions 2024-11-03 01:28:06 -05:00
kernel bpf: Fix narrow scalar spill onto 64-bit spilled scalar slots 2024-12-04 09:19:50 -08:00
lib - The series "zram: optimal post-processing target selection" from 2024-11-23 09:58:07 -08:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm - The series "zram: optimal post-processing target selection" from 2024-11-23 09:58:07 -08:00
net tcp_bpf: Fix the sk_mem_uncharge logic in tcp_bpf_sendmsg 2024-11-26 20:37:46 +01:00
rust Networking changes for 6.13. 2024-11-21 08:28:08 -08:00
samples samples/bpf: Remove unnecessary -I flags from libbpf EXTRA_CFLAGS 2024-12-03 13:29:04 -08:00
scripts powerpc updates for 6.13 2024-11-23 10:44:31 -08:00
security \n 2024-11-21 09:55:45 -08:00
sound - Several drivers, including atmel-flexcom/rk8xx-core, palmas, and 2024-11-22 16:19:47 -08:00
tools bpf: Zero index arg error string for dynptr and iter 2024-12-02 18:47:41 -08:00
usr initramfs: shorten cmd_initfs in usr/Makefile 2024-07-16 01:07:52 +09:00
virt The biggest change here is eliminating the awful idea that KVM had, of 2024-11-23 16:00:50 -08:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Kbuild updates for v6.12 2024-09-24 13:02:06 -07:00
.mailmap media updates for v6.13-rc1 2024-11-20 14:01:15 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS cgroup: Changes for v6.13 2024-11-20 09:54:49 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS powerpc updates for 6.13 2024-11-23 10:44:31 -08:00
Makefile Linux 6.12 2024-11-17 14:15:08 -08:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

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 reStructuredText 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.