linux-kernel - Re: [RFC PATCH] tracing: Fix syscall tracepoint use-after-free

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CADKFtnSGoSXm-r0cykucj4RyO5U7-HHBPx7LFkC6QDHtyPbMfQ@mail.gmail.com>
Date: Tue, 22 Oct 2024 09:14:32 -0700
From: Jordan Rife <jrife@...gle.com>
To: Mathieu Desnoyers <mathieu.desnoyers@...icios.com>
Cc: Steven Rostedt <rostedt@...dmis.org>, linux-kernel@...r.kernel.org, 
	syzbot+b390c8062d8387b6272a@...kaller.appspotmail.com, 
	Michael Jeanson <mjeanson@...icios.com>, Masami Hiramatsu <mhiramat@...nel.org>, 
	Peter Zijlstra <peterz@...radead.org>, Alexei Starovoitov <ast@...nel.org>, Yonghong Song <yhs@...com>, 
	"Paul E . McKenney" <paulmck@...nel.org>, Ingo Molnar <mingo@...hat.com>, 
	Arnaldo Carvalho de Melo <acme@...nel.org>, Mark Rutland <mark.rutland@....com>, 
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>, Namhyung Kim <namhyung@...nel.org>, 
	Andrii Nakryiko <andrii.nakryiko@...il.com>, bpf@...r.kernel.org, 
	Joel Fernandes <joel@...lfernandes.org>
Subject: Re: [RFC PATCH] tracing: Fix syscall tracepoint use-after-free

I assume this patch isn't meant to fix the related issues with freeing
BPF programs/links with call_rcu?

On the BPF side I think there needs to be some smarter handling of
when to use call_rcu or call_rcu_tasks_trace to free links/programs
based on whether or not the program type can be executed in this
context. Right now call_rcu_tasks_trace is used if the program is
sleepable, but that isn't necessarily the case here. Off the top of my
head this would be BPF_PROG_TYPE_RAW_TRACEPOINT and
BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE, but may extend to
BPF_PROG_TYPE_TRACEPOINT? I'll let some of the BPF folks chime in
here, as I'm not entirely sure.

-Jordan