crash/SOURCES/0014-x86_64-check-bt-bptr-before-calculate-framesize.patch

66 lines
2.5 KiB
Diff

From 53d2577cef98b76b122aade94349637a11e06138 Mon Sep 17 00:00:00 2001
From: Tao Liu <ltao@redhat.com>
Date: Tue, 26 Dec 2023 09:19:28 +0800
Subject: [PATCH 14/14] x86_64: check bt->bptr before calculate framesize
Previously the value of bt->bptr is not checked, which may led to a
wrong prev_sp and framesize. As a result, bt->stackbuf[] will be
accessed out of range, and segfault.
Before:
crash> set debug 1
crash> bt
...snip...
--- <NMI exception stack> ---
#8 [ffffffff9a603e10] __switch_to_asm at ffffffff99800214
rsp: ffffffff9a603e10 textaddr: ffffffff99800214 -> spo: 0 bpo: 0 spr: 0 bpr: 0 type: 0 end: 0
#9 [ffffffff9a603e40] __schedule at ffffffff9960dfb1
rsp: ffffffff9a603e40 textaddr: ffffffff9960dfb1 -> spo: 16 bpo: -16 spr: 4 bpr: 1 type: 0 end: 0
rsp: ffffffff9a603e40 rbp: ffffb9ca076e7ca8 prev_sp: ffffb9ca076e7cb8 framesize: 1829650024
Segmentation fault (core dumped)
(gdb) p/x bt->stackbase
$1 = 0xffffffff9a600000
(gdb) p/x bt->stacktop
$2 = 0xffffffff9a604000
After:
crash> set debug 1
crash> bt
...snip...
--- <NMI exception stack> ---
#8 [ffffffff9a603e10] __switch_to_asm at ffffffff99800214
rsp: ffffffff9a603e10 textaddr: ffffffff99800214 -> spo: 0 bpo: 0 spr: 0 bpr: 0 type: 0 end: 0
#9 [ffffffff9a603e40] __schedule at ffffffff9960dfb1
rsp: ffffffff9a603e40 textaddr: ffffffff9960dfb1 -> spo: 16 bpo: -16 spr: 4 bpr: 1 type: 0 end: 0
#10 [ffffffff9a603e98] schedule_idle at ffffffff9960e87c
rsp: ffffffff9a603e98 textaddr: ffffffff9960e87c -> spo: 8 bpo: 0 spr: 5 bpr: 0 type: 0 end: 0
rsp: ffffffff9a603e98 prev_sp: ffffffff9a603ea8 framesize: 0
...snip...
Check bt->bptr value before calculate framesize. Only bt->bptr within
the range of bt->stackbase and bt->stacktop will be regarded as valid.
Signed-off-by: Tao Liu <ltao@redhat.com>
Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
---
x86_64.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/x86_64.c b/x86_64.c
index 42ade4817ad9..f59991f8c4c5 100644
--- a/x86_64.c
+++ b/x86_64.c
@@ -8649,7 +8649,7 @@ x86_64_get_framesize(struct bt_info *bt, ulong textaddr, ulong rsp, char *stack_
if (CRASHDEBUG(1))
fprintf(fp, "rsp: %lx prev_sp: %lx framesize: %d\n",
rsp, prev_sp, framesize);
- } else if ((korc->sp_reg == ORC_REG_BP) && bt->bptr) {
+ } else if ((korc->sp_reg == ORC_REG_BP) && bt->bptr && INSTACK(bt->bptr, bt)) {
prev_sp = bt->bptr + korc->sp_offset;
framesize = (prev_sp - (rsp + 8) - 8);
if (CRASHDEBUG(1))
--
2.41.0