From 79b8d3b090bcbfbcffa8bdd195476c6db172273b Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Sat, 28 Jul 2018 14:19:09 -0600 Subject: [PATCH] Fix use-after-free in record_btrace_start_replaying -fsanitize=address showed a use-after-free in record_btrace_start_replaying. The bug occurred because get_thread_current_frame returned a frame_info, but this object was then invalidated before the return by ~scoped_restore_current_thread. This patch fixes the problem by renaming get_thread_current_frame and having it return a frame id. gdb/ChangeLog 2018-10-23 Tom Tromey * record-btrace.c (get_thread_current_frame_id): Rename from get_thread_current_frame. Return a frame_id. (record_btrace_start_replaying): Update. --- gdb/ChangeLog | 6 ++++++ gdb/record-btrace.c | 19 ++++++++----------- 2 files changed, 14 insertions(+), 11 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index db4c6b1a32..19a87f40fe 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,9 @@ +2018-10-23 Tom Tromey + + * record-btrace.c (get_thread_current_frame_id): Rename from + get_thread_current_frame. Return a frame_id. + (record_btrace_start_replaying): Update. + 2018-10-23 Andrew Burgess * riscv-tdep.c (riscv_register_name): Use the user-friendly names diff --git a/gdb/record-btrace.c b/gdb/record-btrace.c index aabe9f5e27..c0e3341a1f 100644 --- a/gdb/record-btrace.c +++ b/gdb/record-btrace.c @@ -1967,10 +1967,10 @@ record_btrace_resume_thread (struct thread_info *tp, /* Get the current frame for TP. */ -static struct frame_info * -get_thread_current_frame (struct thread_info *tp) +static struct frame_id +get_thread_current_frame_id (struct thread_info *tp) { - struct frame_info *frame; + struct frame_id id; int executing; /* Set current thread, which is implicitly used by @@ -1989,10 +1989,10 @@ get_thread_current_frame (struct thread_info *tp) executing = tp->executing; set_executing (inferior_ptid, false); - frame = NULL; + id = null_frame_id; TRY { - frame = get_current_frame (); + id = get_frame_id (get_current_frame ()); } CATCH (except, RETURN_MASK_ALL) { @@ -2006,7 +2006,7 @@ get_thread_current_frame (struct thread_info *tp) /* Restore the previous execution state. */ set_executing (inferior_ptid, executing); - return frame; + return id; } /* Start replaying a thread. */ @@ -2031,13 +2031,11 @@ record_btrace_start_replaying (struct thread_info *tp) subroutines after we started replaying. */ TRY { - struct frame_info *frame; struct frame_id frame_id; int upd_step_frame_id, upd_step_stack_frame_id; /* The current frame without replaying - computed via normal unwind. */ - frame = get_thread_current_frame (tp); - frame_id = get_frame_id (frame); + frame_id = get_thread_current_frame_id (tp); /* Check if we need to update any stepping-related frame id's. */ upd_step_frame_id = frame_id_eq (frame_id, @@ -2068,8 +2066,7 @@ record_btrace_start_replaying (struct thread_info *tp) registers_changed_thread (tp); /* The current frame with replaying - computed via btrace unwind. */ - frame = get_thread_current_frame (tp); - frame_id = get_frame_id (frame); + frame_id = get_thread_current_frame_id (tp); /* Replace stepping related frames where necessary. */ if (upd_step_frame_id) -- 2.34.1