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From: Yuntao Wang <ytcoode@gmail.com>
To: linux-kernel@vger.kernel.org,
	kexec@lists.infradead.org,
	x86@kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
	Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Jonathan Corbet <corbet@lwn.net>,
	Eric Biederman <ebiederm@xmission.com>,
	Yuntao Wang <ytcoode@gmail.com>
Subject: [PATCH 1/3] kexec_file: fix incorrect end value passed to kimage_is_destination_range()
Date: Fri, 15 Dec 2023 16:09:08 +0800
Message-ID: <20231215080910.173338-2-ytcoode@gmail.com>
In-Reply-To: <20231215080910.173338-1-ytcoode@gmail.com>
References: <20231215080910.173338-1-ytcoode@gmail.com>
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The end parameter received by kimage_is_destination_range() should be the
last valid byte address of the target memory segment plus 1. However, in
the locate_mem_hole_bottom_up() and locate_mem_hole_top_down() functions,
the corresponding value passed to kimage_is_destination_range() is the last
valid byte address of the target memory segment, which is 1 less. Fix it.

Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
---
 kernel/kexec_file.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index f9a419cd22d4..26be070d3bdd 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -435,13 +435,12 @@ static int locate_mem_hole_top_down(unsigned long start, unsigned long end,
 		if (temp_start < start || temp_start < kbuf->buf_min)
 			return 0;
 
-		temp_end = temp_start + kbuf->memsz - 1;
-
 		/*
 		 * Make sure this does not conflict with any of existing
 		 * segments
 		 */
-		if (kimage_is_destination_range(image, temp_start, temp_end)) {
+		if (kimage_is_destination_range(image, temp_start,
+						temp_start + kbuf->memsz)) {
 			temp_start = temp_start - PAGE_SIZE;
 			continue;
 		}
@@ -475,7 +474,7 @@ static int locate_mem_hole_bottom_up(unsigned long start, unsigned long end,
 		 * Make sure this does not conflict with any of existing
 		 * segments
 		 */
-		if (kimage_is_destination_range(image, temp_start, temp_end)) {
+		if (kimage_is_destination_range(image, temp_start, temp_end + 1)) {
 			temp_start = temp_start + PAGE_SIZE;
 			continue;
 		}
-- 
2.43.0