From: Eiichi Tsukata devel@etsukata.com
commit cbf5b73d162b22e044fe0b7d51dcaa33be065253 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/kernel/stacktrace.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-)
--- a/arch/x86/kernel/stacktrace.c +++ b/arch/x86/kernel/stacktrace.c @@ -129,11 +129,9 @@ void arch_stack_walk_user(stack_trace_co 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; }