kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-10-26 19:14:18 +00:00
Code Issues Releases Packages Activity
No description
1,222,798 commits 117 branches 5,805 tags 5.9 GiB
  • C 96.8%
  • Assembly 0.9%
  • Rust 0.7%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Puranjay Mohan aeecb678ec bpf, arm64: fix bug in BPF_LDX_MEMSX 
[ Upstream commit 114b5b3b4b ]

A64_LDRSW() takes three registers: Xt, Xn, Xm as arguments and it loads
and sign extends the value at address Xn + Xm into register Xt.

Currently, the offset is being directly used in place of the tmp
register which has the offset already loaded by the last emitted
instruction.

This will cause JIT failures. The easiest way to reproduce this is to
test the following code through test_bpf module:

{
	"BPF_LDX_MEMSX | BPF_W",
	.u.insns_int = {
		BPF_LD_IMM64(R1, 0x00000000deadbeefULL),
		BPF_LD_IMM64(R2, 0xffffffffdeadbeefULL),
		BPF_STX_MEM(BPF_DW, R10, R1, -7),
		BPF_LDX_MEMSX(BPF_W, R0, R10, -7),
		BPF_JMP_REG(BPF_JNE, R0, R2, 1),
		BPF_ALU64_IMM(BPF_MOV, R0, 0),
		BPF_EXIT_INSN(),
	},
	INTERNAL,
	{ },
	{ { 0, 0 } },
	.stack_depth = 7,
},

We need to use the offset as -7 to trigger this code path, there could
be other valid ways to trigger this from proper BPF programs as well.

This code is rejected by the JIT because -7 is passed to A64_LDRSW() but
it expects a valid register (0 - 31).

 roott@pjy:~# modprobe test_bpf test_name="BPF_LDX_MEMSX | BPF_W"
 [11300.490371] test_bpf: test_bpf: set 'test_bpf' as the default test_suite.
 [11300.491750] test_bpf: #345 BPF_LDX_MEMSX | BPF_W
 [11300.493179] aarch64_insn_encode_register: unknown register encoding -7
 [11300.494133] aarch64_insn_encode_register: unknown register encoding -7
 [11300.495292] FAIL to select_runtime err=-524
 [11300.496804] test_bpf: Summary: 0 PASSED, 1 FAILED, [0/0 JIT'ed]
 modprobe: ERROR: could not insert 'test_bpf': Invalid argument

Applying this patch fixes the issue.

 root@pjy:~# modprobe test_bpf test_name="BPF_LDX_MEMSX | BPF_W"
 [  292.837436] test_bpf: test_bpf: set 'test_bpf' as the default test_suite.
 [  292.839416] test_bpf: #345 BPF_LDX_MEMSX | BPF_W jited:1 156 PASS
 [  292.844794] test_bpf: Summary: 1 PASSED, 0 FAILED, [1/1 JIT'ed]

Fixes: cc88f540da ("bpf, arm64: Support sign-extension load instructions")
Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
Message-ID: <20240312235917.103626-1-puranjay12@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2024-04-10 16:35:40 +02:00
arch bpf, arm64: fix bug in BPF_LDX_MEMSX 2024-04-10 16:35:40 +02:00
block block: Do not force full zone append completion in req_bio_endio() 2024-04-03 15:28:56 +02:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto crypto: jitter - fix CRYPTO_JITTERENTROPY help text 2024-03-26 18:19:52 -04:00
Documentation x86/Kconfig: Remove CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 2024-04-03 15:28:50 +02:00
drivers drm/i915: Pre-populate the cursor physical dma address 2024-04-10 16:35:40 +02:00
fs exec: Fix NOMMU linux_binprm::exec in transfer_args_to_stack() 2024-04-03 15:28:55 +02:00
include Revert "workqueue: Implement system-wide nr_active enforcement for unbound workqueues" 2024-04-04 20:23:06 +02:00
init init: open /initrd.image with O_LARGEFILE 2024-04-03 15:28:53 +02:00
io_uring io_uring: clean rings on NO_MMAP alloc fail 2024-04-03 15:28:31 +02:00
ipc Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
kernel Revert "workqueue.c: Increase workqueue name length" 2024-04-04 20:23:07 +02:00
lib pci_iounmap(): Fix MMIO mapping leak 2024-04-03 15:28:17 +02:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm mm: cachestat: fix two shmem bugs 2024-04-03 15:28:55 +02:00
net Bluetooth: hci_sync: Fix not checking error on hci_cmd_sync_cancel_sync 2024-04-03 15:28:58 +02:00
rust rust: upgrade to Rust 1.73.0 2024-02-16 19:10:43 +01:00
samples work around gcc bugs with 'asm goto' with outputs 2024-02-23 09:24:47 +01:00
scripts scripts/bpf_doc: Use silent mode when exec make cmd 2024-04-10 16:35:40 +02:00
security landlock: Warn once if a Landlock action is requested while disabled 2024-04-03 15:28:27 +02:00
sound ALSA: sh: aica: reorder cleanup operations to avoid UAF bugs 2024-04-03 15:28:59 +02:00
tools tools/resolve_btfids: fix build with musl libc 2024-04-03 15:29:03 +02:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt KVM: Always flush async #PF workqueue when vCPU is being destroyed 2024-04-03 15:28:18 +02:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: rename binkernel.spec to kernel.spec 2023-07-25 00:59:33 +09:00
.mailmap 20 hotfixes. 12 are cc:stable and the remainder address post-6.5 issues 2023-10-24 09:52:16 -10:00
.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 USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
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 MAINTAINERS: add Catherine as xfs maintainer for 6.6.y 2024-02-16 19:10:43 +01:00
Makefile Linux 6.6.25 2024-04-04 20:23:07 +02:00
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.