From: Jane Chu <jane.chu@oracle.com>
To: pmladek@suse.com, rostedt@goodmis.org, senozhatsky@chromium.org,
andriy.shevchenko@linux.intel.com, linux@rasmusvillemoes.dk,
linux-kernel@vger.kernel.org
Cc: jane.chu@oracle.com
Subject: [PATCH] vsprintf: protect kernel from panic due to non-canonical pointer dereference
Date: Mon, 17 Oct 2022 13:16:11 -0600 [thread overview]
Message-ID: <20221017191611.2577466-1-jane.chu@oracle.com> (raw)
While debugging a separate issue, it was found that an invalid string
pointer could very well contain a non-canical address, such as
0x7665645f63616465. In that case, this line of defense isn't enough
to protect the kernel from crashing due to general protection fault
if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
return "(efault)";
So instead, use kern_addr_valid() to validate the string pointer.
Signed-off-by: Jane Chu <jane.chu@oracle.com>
---
lib/vsprintf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index c414a8d9f1ea..2e8a9efc7c12 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -695,7 +695,7 @@ static const char *check_pointer_msg(const void *ptr)
if (!ptr)
return "(null)";
- if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
+ if (!kern_addr_valid((unsigned long)ptr))
return "(efault)";
return NULL;
--
2.18.4
next reply other threads:[~2022-10-17 19:16 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-17 19:16 Jane Chu [this message]
2022-10-17 19:25 ` [PATCH] vsprintf: protect kernel from panic due to non-canonical pointer dereference Andy Shevchenko
2022-10-17 19:31 ` Jane Chu
2022-10-18 12:45 ` Petr Mladek
2022-10-18 18:56 ` Jane Chu
2022-10-18 19:28 ` Randy Dunlap
2022-10-18 19:58 ` Jane Chu
2022-10-18 20:07 ` Andy Shevchenko
2022-10-18 20:30 ` Jane Chu
2022-10-18 20:49 ` Andy Shevchenko
2022-10-19 10:43 ` Haakon Bugge
2022-10-19 11:25 ` Andy Shevchenko
2022-10-19 18:36 ` Jane Chu
2022-10-19 19:26 ` Andy Shevchenko
2022-10-19 20:16 ` Jane Chu
2022-10-20 7:44 ` Petr Mladek
2022-10-20 9:18 ` Petr Mladek
2022-10-20 13:57 ` Andy Shevchenko
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