From: tip-bot for Eiichi Tsukata <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: torvalds@linux-foundation.org, devel@etsukata.com,
tglx@linutronix.de, mingo@kernel.org,
linux-kernel@vger.kernel.org, hpa@zytor.com
Subject: [tip:x86/urgent] x86/stacktrace: Prevent infinite loop in arch_stack_walk_user()
Date: Wed, 10 Jul 2019 23:25:14 -0700 [thread overview]
Message-ID: <tip-cbf5b73d162b22e044fe0b7d51dcaa33be065253@git.kernel.org> (raw)
In-Reply-To: <20190711023501.963-1-devel@etsukata.com>
Commit-ID: cbf5b73d162b22e044fe0b7d51dcaa33be065253
Gitweb: https://git.kernel.org/tip/cbf5b73d162b22e044fe0b7d51dcaa33be065253
Author: Eiichi Tsukata <devel@etsukata.com>
AuthorDate: Thu, 11 Jul 2019 11:35:01 +0900
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Thu, 11 Jul 2019 08:22:03 +0200
x86/stacktrace: Prevent infinite loop in arch_stack_walk_user()
arch_stack_walk_user() checks `if (fp == frame.next_fp)` to prevent a
infinite loop by self reference but it's not enogh for circular reference.
Once a lack of return address is found, there is no point to continue the
loop, so break out.
Fixes: 02b67518e2b1 ("tracing: add support for userspace stacktraces in tracing/iter_ctrl")
Signed-off-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lkml.kernel.org/r/20190711023501.963-1-devel@etsukata.com
---
arch/x86/kernel/stacktrace.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index 2abf27d7df6b..4f36d3241faf 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -129,11 +129,9 @@ void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie,
break;
if ((unsigned long)fp < regs->sp)
break;
- if (frame.ret_addr) {
- if (!consume_entry(cookie, frame.ret_addr, false))
- return;
- }
- if (fp == frame.next_fp)
+ if (!frame.ret_addr)
+ break;
+ if (!consume_entry(cookie, frame.ret_addr, false))
break;
fp = frame.next_fp;
}
prev parent reply other threads:[~2019-07-11 6:25 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-11 2:35 [PATCH] x86/stacktrace: Fix infinite loop in arch_stack_walk_user() Eiichi Tsukata
2019-07-11 4:10 ` Linus Torvalds
2019-07-11 6:25 ` tip-bot for Eiichi Tsukata [this message]
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