File _service:tar_scm:backport-aarch64-unw_step-vali... of Package libunwind

File _service:tar_scm:backport-aarch64-unw_step-validates-address-before-calling-dwarf_get.patch of Package libunwind

From 8a0e2fa6579085dc8f51b2bdd90d8b00a2e7d6ab Mon Sep 17 00:00:00 2001
From: he7850 <im.bin.hu@gmail.com>
Date: Wed, 3 May 2023 15:18:27 +0800
Subject: [PATCH] aarch64: unw_step() validates address before calling
 dwarf_get

Signed-off-by: he7850 <im.bin.hu@gmail.com>
---
 src/aarch64/Gstep.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/aarch64/Gstep.c b/src/aarch64/Gstep.c
index f4ef369d3..a2ed9bc35 100644
--- a/src/aarch64/Gstep.c
+++ b/src/aarch64/Gstep.c
@@ -156,18 +156,28 @@ unw_step (unw_cursor_t *cursor)
       dwarf_get (&c->dwarf, c->dwarf.loc[UNW_AARCH64_X30], &c->dwarf.ip);
     }
 
-  /* Restore default memory validation state */
-  c->validate = validate;
-
   ret = dwarf_step (&c->dwarf);
   Debug(1, "dwarf_step()=%d\n", ret);
 
+  /* Restore default memory validation state */
+  c->validate = validate;
+
   if (unlikely (ret == -UNW_ESTOPUNWIND))
     return ret;
 
   if (unlikely (ret < 0))
     {
       /* DWARF failed. */
+
+      /*
+       * We could get here because of missing/bad unwind information.
+       * Validate all addresses before dereferencing.
+       */
+      if (c->dwarf.as == unw_local_addr_space)
+	  {
+	      c->validate = 1;
+	  }
+
       if (is_plt_entry (&c->dwarf))
         {
           Debug (2, "found plt entry\n");