[PATCH v13 09/18] unwind_user/sframe: Remove .sframe section on detected corruption

[Jens Remus]

From: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>

To avoid continued attempted use of a bad .sframe section, remove it
on demand when the first sign of corruption is detected.

Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Andrii Nakryiko <andrii@xxxxxxxxxx>
Cc: Indu Bhagat <indu.bhagat@xxxxxxxxxx>
Cc: "Jose E. Marchesi" <jemarch@xxxxxxx>
Cc: Beau Belgrave <beaub@xxxxxxxxxxxxxxxxxxx>
Cc: Jens Remus <jremus@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Florian Weimer <fweimer@xxxxxxxxxx>
Cc: Sam James <sam@xxxxxxxxxx>
Cc: Kees Cook <kees@xxxxxxxxxx>
Cc: "Carlos O'Donell" <codonell@xxxxxxxxxx>
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Signed-off-by: Jens Remus <jremus@xxxxxxxxxxxxx>
---
 kernel/unwind/sframe.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kernel/unwind/sframe.c b/kernel/unwind/sframe.c
index 6004b43aac34..9a63f8828593 100644
--- a/kernel/unwind/sframe.c
+++ b/kernel/unwind/sframe.c
@@ -358,6 +358,10 @@ int sframe_find(unsigned long ip, struct unwind_user_frame *frame)
 	ret = __find_fre(sec, &fde, ip, frame);
 end:
 	user_read_access_end();
+
+	if (ret == -EFAULT)
+		WARN_ON_ONCE(sframe_remove_section(sec->sframe_start));
+
 	return ret;
 }
 
-- 
2.51.0