From patchwork Fri Mar 15 20:47:59 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Thomas_Wei=C3=9Fschuh?= X-Patchwork-Id: 13593952 Received: from todd.t-8ch.de (todd.t-8ch.de [159.69.126.157]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E18E24596F; Fri, 15 Mar 2024 20:48:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.69.126.157 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710535709; cv=none; b=JTCbw3VA0XXjA31ZYZN5Y4NJ3kVfrcgMO07mPX+4oBuW4ZRKdxXb2cTZRfxcPBWyCTd419PuoPWuFEOey1HuhBO2KyqhWXuO3EkJzXX1t2TchLnMYt8Eze2B0Iw6WA4JUlXeUfYE/Ae4/ssZhqZ4+OvR/wCD3z0212bDs1u3lWI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710535709; c=relaxed/simple; bh=H2m3CgyPxKp8J+A7s6etu+nqQuMydVMaRq2xUBYcaE4=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=F65Q5sZ+iSWp4/gqUDc2BmIRTSUODE1V2eevZ5kQ92AikWFLFZw0Bt8AJE3oj5iMeUViBy2cEeLHpdT/0kGVha3cR+ENppdKA6V11ugfl6icVED1PChRCh4DcmCxiQtK6DQG7oFb80kovvMmgsvo+kL9w1XBzncN1NDoDCwbR8k= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=weissschuh.net; spf=pass smtp.mailfrom=weissschuh.net; dkim=pass (1024-bit key) header.d=weissschuh.net header.i=@weissschuh.net header.b=OtqzLAYr; arc=none smtp.client-ip=159.69.126.157 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=weissschuh.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=weissschuh.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=weissschuh.net header.i=@weissschuh.net header.b="OtqzLAYr" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=weissschuh.net; s=mail; t=1710535697; bh=H2m3CgyPxKp8J+A7s6etu+nqQuMydVMaRq2xUBYcaE4=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=OtqzLAYrt5MtBFfAZCuwNssLXJHoAR4MT2r6oU61HR9QLLg5cCh1g2XnStOGxiy7H aYVgoJG/5JjDiW63WYq+mIYWZ7/qNgpwGkaK2lYoUVwB0VuqwcXESjUQJt1OY5Zk/5 o+C0FqSaoUUjKNQ3ndLxab0hpdSwSbjdaGlpZ+1Y= From: =?utf-8?q?Thomas_Wei=C3=9Fschuh?= Date: Fri, 15 Mar 2024 21:47:59 +0100 Subject: [PATCH 01/11] stackleak: don't modify ctl_table argument Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240315-sysctl-const-handler-v1-1-1322ac7cb03d@weissschuh.net> References: <20240315-sysctl-const-handler-v1-0-1322ac7cb03d@weissschuh.net> In-Reply-To: <20240315-sysctl-const-handler-v1-0-1322ac7cb03d@weissschuh.net> To: Greg Kroah-Hartman , Kees Cook , Alexei Starovoitov , Daniel Borkmann , John Fastabend , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Muchun Song , Andrew Morton , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , David Ahern , Simon Horman , Julian Anastasov , Pablo Neira Ayuso , Jozsef Kadlecsik , Florian Westphal , Luis Chamberlain , Joel Granados , Catalin Marinas , Will Deacon , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Gerald Schaefer , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Phillip Potter , Theodore Ts'o , "Jason A. Donenfeld" , Sudip Mukherjee , Mark Rutland , Atish Patra , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexander Viro , Christian Brauner , Jan Kara , Eric Biederman , Chandan Babu R , "Darrick J. Wong" , Steven Rostedt , Masami Hiramatsu , Peter Zijlstra , Arnaldo Carvalho de Melo , Namhyung Kim , Alexander Shishkin , Ian Rogers , Adrian Hunter , Balbir Singh , "Naveen N. Rao" , Anil S Keshavamurthy , Petr Mladek , John Ogness , Sergey Senozhatsky , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Valentin Schneider , Andy Lutomirski , Will Drewry , John Stultz , Stephen Boyd , Mathieu Desnoyers , "Matthew Wilcox (Oracle)" , Roopa Prabhu , Nikolay Aleksandrov , Remi Denis-Courmont , Allison Henderson , Marcelo Ricardo Leitner , Xin Long , Chuck Lever , Jeff Layton , Neil Brown , Olga Kornievskaia , Dai Ngo , Tom Talpey , Trond Myklebust , Anna Schumaker , John Johansen , Paul Moore , James Morris , "Serge E. Hallyn" , Alexander Popov Cc: linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, lvs-devel@vger.kernel.org, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, linux-fsdevel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-s390@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-xfs@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, kexec@lists.infradead.org, bridge@lists.linux.dev, linux-rdma@vger.kernel.org, rds-devel@oss.oracle.com, linux-sctp@vger.kernel.org, linux-nfs@vger.kernel.org, apparmor@lists.ubuntu.com, linux-security-module@vger.kernel.org, =?utf-8?q?Thomas_Wei=C3=9Fschuh?= X-Mailer: b4 0.13.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1710535695; l=1205; i=linux@weissschuh.net; s=20221212; h=from:subject:message-id; bh=H2m3CgyPxKp8J+A7s6etu+nqQuMydVMaRq2xUBYcaE4=; b=DLCpjj80ePju45B1sM6SeMu3SU3+SovEAF9F+apF8HUTZcbHxhK7sFWDz+WraIYUf5lzi8ctP 25gNqwcr0i1CjOhkjNKarmdmKbieJ/tL+nZegKGxX2K6TvuJVTedQUi X-Developer-Key: i=linux@weissschuh.net; a=ed25519; pk=KcycQgFPX2wGR5azS7RhpBqedglOZVgRPfdFSPB1LNw= In a future commit the proc_handlers will change to "const struct ctl_table". As a preparation for that adapt the logic to work with a temporary variable, similar to how it is done in other parts of the kernel. Fixes: 964c9dff0091 ("stackleak: Allow runtime disabling of kernel stack erasing") Acked-by: Kees Cook Signed-off-by: Thomas Weißschuh --- kernel/stackleak.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/stackleak.c b/kernel/stackleak.c index 34c9d81eea94..b292e5ca0b7d 100644 --- a/kernel/stackleak.c +++ b/kernel/stackleak.c @@ -27,10 +27,11 @@ static int stack_erasing_sysctl(struct ctl_table *table, int write, int ret = 0; int state = !static_branch_unlikely(&stack_erasing_bypass); int prev_state = state; + struct ctl_table tmp = *table; - table->data = &state; - table->maxlen = sizeof(int); - ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); + tmp.data = &state; + tmp.maxlen = sizeof(int); + ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); state = !!state; if (ret || !write || state == prev_state) return ret;