88 lines
2.6 KiB
Diff
88 lines
2.6 KiB
Diff
|
From c96e7736d85e40685939011e6d51b3c0a28739a3 Mon Sep 17 00:00:00 2001
|
||
|
|
From: Vivek Goyal <vgoyal@redhat.com>
|
||
|
|
Date: Wed, 18 Jul 2012 09:33:51 -0400
|
||
|
|
Subject: [PATCH] vmcore-dmesg: Do not write beyond end of buffer
|
||
|
|
|
||
|
|
scan_vmcoreinfo() currently assumes that every vmcoreinfo note line ends
|
||
|
|
with \n and overwrites new line with \0. But last entry in note, CRASHTIME=
|
||
|
|
does not end with \n and this leads to corrupting memory as we write beyond
|
||
|
|
end of buffer.
|
||
|
|
|
||
|
|
Normally things were fine but when I added some fields to vmcoreinfo, this
|
||
|
|
bug started showing and vmcore-dmesg started crashing.
|
||
|
|
|
||
|
|
I am planning to send a patch to fix this in kernel but it might be good
|
||
|
|
idea to handle this case in user space too so that vmcore-dmesg works
|
||
|
|
fine with cores of older kernels.
|
||
|
|
|
||
|
|
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
|
||
|
|
Signed-off-by: Simon Horman <horms@verge.net.au>
|
||
|
|
---
|
||
|
|
vmcore-dmesg/vmcore-dmesg.c | 29 ++++++++++++++++++++++++++++-
|
||
|
|
1 files changed, 28 insertions(+), 1 deletions(-)
|
||
|
|
|
||
|
|
diff --git a/vmcore-dmesg/vmcore-dmesg.c b/vmcore-dmesg/vmcore-dmesg.c
|
||
|
|
index 8518150..2e692de 100644
|
||
|
|
--- a/vmcore-dmesg/vmcore-dmesg.c
|
||
|
|
+++ b/vmcore-dmesg/vmcore-dmesg.c
|
||
|
|
@@ -14,6 +14,7 @@
|
||
|
|
#include <sys/stat.h>
|
||
|
|
#include <fcntl.h>
|
||
|
|
#include <elf.h>
|
||
|
|
+#include <stdbool.h>
|
||
|
|
|
||
|
|
/* The 32bit and 64bit note headers make it clear we don't care */
|
||
|
|
typedef Elf32_Nhdr Elf_Nhdr;
|
||
|
|
@@ -220,6 +221,9 @@ static void scan_vmcoreinfo(char *start, size_t size)
|
||
|
|
{
|
||
|
|
char *last = start + size - 1;
|
||
|
|
char *pos, *eol;
|
||
|
|
+ char temp_buf[1024];
|
||
|
|
+ bool last_line = false;
|
||
|
|
+
|
||
|
|
#define SYMBOL(sym) { \
|
||
|
|
.str = "SYMBOL(" #sym ")=", \
|
||
|
|
.name = #sym, \
|
||
|
|
@@ -243,7 +247,27 @@ static void scan_vmcoreinfo(char *start, size_t size)
|
||
|
|
/* Find the end of the current line */
|
||
|
|
for (eol = pos; (eol <= last) && (*eol != '\n') ; eol++)
|
||
|
|
;
|
||
|
|
- len = eol - pos + 1;
|
||
|
|
+ if (eol > last) {
|
||
|
|
+ /*
|
||
|
|
+ * We did not find \n and note ended. Currently kernel
|
||
|
|
+ * is appending last field CRASH_TIME without \n. It
|
||
|
|
+ * is ugly but handle it.
|
||
|
|
+ */
|
||
|
|
+ eol = last;
|
||
|
|
+ len = eol - pos + 1;
|
||
|
|
+ if (len >= sizeof(temp_buf))
|
||
|
|
+ len = sizeof(temp_buf) - 1;
|
||
|
|
+ strncpy(temp_buf, pos, len);
|
||
|
|
+ temp_buf[len + 1] = '\0';
|
||
|
|
+
|
||
|
|
+ pos = temp_buf;
|
||
|
|
+ len = len + 1;
|
||
|
|
+ eol = pos + len -1;
|
||
|
|
+ last_line = true;
|
||
|
|
+ } else {
|
||
|
|
+ len = eol - pos + 1;
|
||
|
|
+ }
|
||
|
|
+
|
||
|
|
/* Stomp the last character so I am guaranteed a terminating null */
|
||
|
|
*eol = '\0';
|
||
|
|
/* Copy OSRELEASE if I see it */
|
||
|
|
@@ -266,6 +290,9 @@ static void scan_vmcoreinfo(char *start, size_t size)
|
||
|
|
/* Remember the virtual address */
|
||
|
|
*symbol[i].vaddr = vaddr;
|
||
|
|
}
|
||
|
|
+
|
||
|
|
+ if (last_line)
|
||
|
|
+ break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
--
|
||
|
|
1.7.1
|
||
|
|
|