Revision 14d6d86c210aea1a83c19a8f6391ecabcbefed94 authored by Alexei Starovoitov on 19 November 2020, 18:45:55 UTC, committed by Alexei Starovoitov on 19 November 2020, 19:58:15 UTC
Daniel Xu says:
====================
6ae08ae3dea2 ("bpf: Add probe_read_{user, kernel} and probe_read_{user,
kernel}_str helpers") introduced a subtle bug where
bpf_probe_read_user_str() would potentially copy a few extra bytes after
the NUL terminator.
This issue is particularly nefarious when strings are used as map keys,
as seemingly identical strings can occupy multiple entries in a map.
This patchset fixes the issue and introduces a selftest to prevent
future regressions.
v6 -> v7:
* Add comments
v5 -> v6:
* zero-pad up to sizeof(unsigned long) after NUL
v4 -> v5:
* don't read potentially uninitialized memory
v3 -> v4:
* directly pass userspace pointer to prog
* test more strings of different length
v2 -> v3:
* set pid filter before attaching prog in selftest
* use long instead of int as bpf_probe_read_user_str() retval
* style changes
v1 -> v2:
* add Fixes: tag
* add selftest
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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.
Computing file changes ...
