mainlining shenanigans
4b6313cf99
The combination of jit blinding and pointers to bpf subprogs causes:
[ 36.989548] BUG: unable to handle page fault for address: 0000000100000001
[ 36.990342] #PF: supervisor instruction fetch in kernel mode
[ 36.990968] #PF: error_code(0x0010) - not-present page
[ 36.994859] RIP: 0010:0x100000001
[ 36.995209] Code: Unable to access opcode bytes at RIP 0xffffffd7.
[ 37.004091] Call Trace:
[ 37.004351] <TASK>
[ 37.004576] ? bpf_loop+0x4d/0x70
[ 37.004932] ? bpf_prog_3899083f75e4c5de_F+0xe3/0x13b
The jit blinding logic didn't recognize that ld_imm64 with an address
of bpf subprogram is a special instruction and proceeded to randomize it.
By itself it wouldn't have been an issue, but jit_subprogs() logic
relies on two step process to JIT all subprogs and then JIT them
again when addresses of all subprogs are known.
Blinding process in the first JIT phase caused second JIT to miss
adjustment of special ld_imm64.
Fix this issue by ignoring special ld_imm64 instructions that don't have
user controlled constants and shouldn't be blinded.
Fixes:
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|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| 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.