91cff53136
[ Upstream commit 2884dc7d08d98a89d8d65121524bb7533183a63a ]
After commit 1a80dbcb2dba, bpf_link can be freed by
link->ops->dealloc_deferred, but the code still tests and uses
link->ops->dealloc afterward, which leads to a use-after-free as
reported by syzbot. Actually, one of them should be sufficient, so
just call one of them instead of both. Also add a WARN_ON() in case
of any problematic implementation.
Fixes: 1a80dbcb2dba ("bpf: support deferring bpf_link dealloc to after RCU grace period")
Reported-by: syzbot+1989ee16d94720836244@syzkaller.appspotmail.com
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20240602182703.207276-1-xiyou.wangcong@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.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.