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authorEiichi Tsukata <devel@etsukata.com>2019-07-11 04:35:01 +0200
committerThomas Gleixner <tglx@linutronix.de>2019-07-11 08:22:03 +0200
commitcbf5b73d162b22e044fe0b7d51dcaa33be065253 (patch)
treef4baca1e7a79277c48261f22285361808633911b
parentx86/asm: Move native_write_cr0/4() out of line (diff)
downloadlinux-cbf5b73d162b22e044fe0b7d51dcaa33be065253.tar.xz
linux-cbf5b73d162b22e044fe0b7d51dcaa33be065253.zip
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
-rw-r--r--arch/x86/kernel/stacktrace.c8
1 files 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;
}