Andrii Nakryiko 84887f4c1c lib/buildid: harden build ID parsing logic
[ Upstream commit 905415ff3ffb1d7e5afa62bacabd79776bd24606 ]

Harden build ID parsing logic, adding explicit READ_ONCE() where it's
important to have a consistent value read and validated just once.

Also, as pointed out by Andi Kleen, we need to make sure that entire ELF
note is within a page bounds, so move the overflow check up and add an
extra note_size boundaries validation.

Fixes tag below points to the code that moved this code into
lib/buildid.c, and then subsequently was used in perf subsystem, making
this code exposed to perf_event_open() users in v5.12+.

Cc: stable@vger.kernel.org
Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Reviewed-by: Jann Horn <jannh@google.com>
Suggested-by: Andi Kleen <ak@linux.intel.com>
Fixes: bd7525dacd ("bpf: Move stack_map_get_build_id into lib")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240829174232.3133883-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-10-17 15:22:06 +02:00
2024-10-17 15:22:05 +02:00
2024-10-17 15:22:05 +02:00
2024-09-30 16:23:56 +02:00

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 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.
Languages
C 97.2%
Assembly 1.7%
Shell 0.4%
Makefile 0.3%
Python 0.2%