436bc4c45a
commit 1a9c72ad4c26821e215a396167c14959cf24a7f1 upstream. The verifier allows ARG_PTR_TO_BTF_ID helper arguments to be NULL, so helper implementations need to check this before dereferencing them. This was already fixed for the socket storage helpers but not for task and inode. The issue can be reproduced by attaching an LSM program to inode_rename hook (called when moving files) which tries to get the inode of the new file without checking for its nullness and then trying to move an existing file to a new path: mv existing_file new_file_does_not_exist The report including the sample program and the steps for reproducing the bug: https://lore.kernel.org/bpf/CANaYP3HWkH91SN=wTNO9FL_2ztHfqcXKX38SSE-JJ2voh+vssw@mail.gmail.com Fixes: 4cf1bc1f1045 ("bpf: Implement task local storage") Fixes: 8ea636848aca ("bpf: Implement bpf_local_storage for inodes") Reported-by: Gilad Reti <gilad.reti@gmail.com> Signed-off-by: KP Singh <kpsingh@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210112075525.256820-3-kpsingh@kernel.org [ just take 1/2 of this patch for 5.10.y - gregkh ] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.