All of lore.kernel.org
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: keescook@chromium.org, jannh@google.com
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
	vcaputo@pengaru.com, mingo@redhat.com, juri.lelli@redhat.com,
	vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
	rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de,
	bristot@redhat.com, akpm@linux-foundation.org,
	christian.brauner@ubuntu.com, amistry@google.com,
	Kenta.Tada@sony.com, legion@kernel.org,
	michael.weiss@aisec.fraunhofer.de, mhocko@suse.com,
	deller@gmx.de, zhengqi.arch@bytedance.com, me@tobin.cc,
	tycho@tycho.pizza, tglx@linutronix.de, bp@alien8.de,
	hpa@zytor.com, mark.rutland@arm.com, axboe@kernel.dk,
	metze@samba.org, laijs@linux.alibaba.com, luto@kernel.org,
	dave.hansen@linux.intel.com, ebiederm@xmission.com,
	ohoono.kwon@samsung.com, kaleshsingh@google.com,
	yifeifz2@illinois.edu, jpoimboe@redhat.com,
	linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org,
	vgupta@kernel.org, linux@armlinux.org.uk, will@kernel.org,
	guoren@kernel.org, bcain@codeaurora.org, monstr@monstr.eu,
	tsbogend@alpha.franken.de, nickhu@andestech.com,
	jonas@southpole.se, mpe@ellerman.id.au, paul.walmsley@sifive.com,
	hca@linux.ibm.com, ysato@users.sourceforge.jp,
	davem@davemloft.net, chris@zankel.net,
	kernel test robot <oliver.sang@intel.com>,
	stable@vger.kernel.org
Subject: [PATCH 1/7] Revert "proc/wchan: use printk format instead of lookup_symbol_name()"
Date: Fri, 08 Oct 2021 13:15:28 +0200	[thread overview]
Message-ID: <20211008111626.090829198@infradead.org> (raw)
In-Reply-To: 20211008111527.438276127@infradead.org

From: Kees Cook <keescook@chromium.org>

This reverts commit 152c432b128cb043fc107e8f211195fe94b2159c.

When a kernel address couldn't be symbolized for /proc/$pid/wchan, it
would leak the raw value, a potential information exposure. This is a
regression compared to the safer pre-v5.12 behavior.

Reported-by: kernel test robot <oliver.sang@intel.com>
Reported-by: Vito Caputo <vcaputo@pengaru.com>
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
---
 fs/proc/base.c |   21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -67,6 +67,7 @@
 #include <linux/mm.h>
 #include <linux/swap.h>
 #include <linux/rcupdate.h>
+#include <linux/kallsyms.h>
 #include <linux/stacktrace.h>
 #include <linux/resource.h>
 #include <linux/module.h>
@@ -386,17 +387,19 @@ static int proc_pid_wchan(struct seq_fil
 			  struct pid *pid, struct task_struct *task)
 {
 	unsigned long wchan;
+	char symname[KSYM_NAME_LEN];
 
-	if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
-		wchan = get_wchan(task);
-	else
-		wchan = 0;
-
-	if (wchan)
-		seq_printf(m, "%ps", (void *) wchan);
-	else
-		seq_putc(m, '0');
+	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
+		goto print0;
 
+	wchan = get_wchan(task);
+	if (wchan && !lookup_symbol_name(wchan, symname)) {
+		seq_puts(m, symname);
+		return 0;
+	}
+
+print0:
+	seq_putc(m, '0');
 	return 0;
 }
 #endif /* CONFIG_KALLSYMS */



  reply	other threads:[~2021-10-08 11:19 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-08 11:15 [PATCH 0/7] wchan: Fix wchan support Peter Zijlstra
2021-10-08 11:15 ` Peter Zijlstra [this message]
2021-10-15  9:45   ` [tip: sched/core] Revert "proc/wchan: use printk format instead of lookup_symbol_name()" tip-bot2 for Kees Cook
2021-10-08 11:15 ` [PATCH 2/7] leaking_addresses: Always print a trailing newline Peter Zijlstra
2021-10-15  9:45   ` [tip: sched/core] " tip-bot2 for Kees Cook
2021-10-08 11:15 ` [PATCH 3/7] proc: Use task_is_running() for wchan in /proc/$pid/stat Peter Zijlstra
2021-10-15  9:45   ` [tip: sched/core] " tip-bot2 for Kees Cook
2021-10-08 11:15 ` [PATCH 4/7] x86: Fix get_wchan() to support the ORC unwinder Peter Zijlstra
2021-10-15  9:45   ` [tip: sched/core] " tip-bot2 for Qi Zheng
2021-10-08 11:15 ` [PATCH 5/7] sched: Add wrapper for get_wchan() to keep task blocked Peter Zijlstra
2021-10-08 11:26   ` Geert Uytterhoeven
2021-10-08 12:45   ` Mark Rutland
2021-10-14 10:46   ` Russell King (Oracle)
2021-10-15  9:45   ` [tip: sched/core] " tip-bot2 for Kees Cook
2021-10-08 11:15 ` [PATCH 6/7] arch: __get_wchan || STACKTRACE_SUPPORT Peter Zijlstra
2021-10-08 12:40   ` Mark Rutland
2021-10-08 13:45     ` Peter Zijlstra
2021-10-08 16:17       ` Josh Poimboeuf
2021-10-14 18:07         ` Mark Rutland
2021-10-14 18:41           ` Josh Poimboeuf
2021-10-14 18:03       ` Mark Rutland
2021-10-14 18:48         ` Josh Poimboeuf
2021-10-14 11:07   ` Russell King (Oracle)
2021-10-08 11:15 ` [PATCH 7/7] arch: Fix STACKTRACE_SUPPORT Peter Zijlstra
2021-10-08 12:52   ` Mark Rutland
2021-10-09  9:36   ` Guo Ren
2021-10-14 12:02 ` [PATCH 0/7] wchan: Fix wchan support Russell King (Oracle)
2021-10-14 13:38   ` Russell King (Oracle)
2021-10-14 19:51     ` Josh Poimboeuf

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20211008111626.090829198@infradead.org \
    --to=peterz@infradead.org \
    --cc=Kenta.Tada@sony.com \
    --cc=akpm@linux-foundation.org \
    --cc=amistry@google.com \
    --cc=axboe@kernel.dk \
    --cc=bcain@codeaurora.org \
    --cc=bp@alien8.de \
    --cc=bristot@redhat.com \
    --cc=bsegall@google.com \
    --cc=chris@zankel.net \
    --cc=christian.brauner@ubuntu.com \
    --cc=dave.hansen@linux.intel.com \
    --cc=davem@davemloft.net \
    --cc=deller@gmx.de \
    --cc=dietmar.eggemann@arm.com \
    --cc=ebiederm@xmission.com \
    --cc=guoren@kernel.org \
    --cc=hca@linux.ibm.com \
    --cc=hpa@zytor.com \
    --cc=jannh@google.com \
    --cc=jonas@southpole.se \
    --cc=jpoimboe@redhat.com \
    --cc=juri.lelli@redhat.com \
    --cc=kaleshsingh@google.com \
    --cc=keescook@chromium.org \
    --cc=laijs@linux.alibaba.com \
    --cc=legion@kernel.org \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-hardening@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=luto@kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=me@tobin.cc \
    --cc=metze@samba.org \
    --cc=mgorman@suse.de \
    --cc=mhocko@suse.com \
    --cc=michael.weiss@aisec.fraunhofer.de \
    --cc=mingo@redhat.com \
    --cc=monstr@monstr.eu \
    --cc=mpe@ellerman.id.au \
    --cc=nickhu@andestech.com \
    --cc=ohoono.kwon@samsung.com \
    --cc=oliver.sang@intel.com \
    --cc=paul.walmsley@sifive.com \
    --cc=rostedt@goodmis.org \
    --cc=stable@vger.kernel.org \
    --cc=tglx@linutronix.de \
    --cc=tsbogend@alpha.franken.de \
    --cc=tycho@tycho.pizza \
    --cc=vcaputo@pengaru.com \
    --cc=vgupta@kernel.org \
    --cc=vincent.guittot@linaro.org \
    --cc=will@kernel.org \
    --cc=yifeifz2@illinois.edu \
    --cc=ysato@users.sourceforge.jp \
    --cc=zhengqi.arch@bytedance.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.