From: Eiichi Tsukata <devel@xxxxxxxxxxxx>
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@xxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20190711023501.963-1-devel@xxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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;
}
