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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>,
	Baoquan He <bhe@redhat.com>,
	Vivek Goyal <vgoyal@redhat.com>,
	Dave Young <dyoung@redhat.com>,
	Hari Bathini <hbathini@linux.ibm.com>,
	Sean Christopherson <seanjc@google.com>,
	Takashi Iwai <tiwai@suse.de>,
	Yuntao Wang <ytcoode@gmail.com>
Subject: [PATCH 2/2] crash_core: fix out-of-bounds access check in crash_exclude_mem_range()
Date: Mon, 18 Dec 2023 16:19:15 +0800
Message-ID: <20231218081915.24120-3-ytcoode@gmail.com>
In-Reply-To: <20231218081915.24120-1-ytcoode@gmail.com>
References: <20231218081915.24120-1-ytcoode@gmail.com>
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mem->nr_ranges represents the current number of elements stored in
the mem->ranges array, and mem->max_nr_ranges represents the maximum number
of elements that the mem->ranges array can hold. Therefore, the correct
array out-of-bounds check should be mem->nr_ranges >= mem->max_nr_ranges.

Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
---
 kernel/crash_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index d4313b53837e..991494d4cf43 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -627,7 +627,7 @@ int crash_exclude_mem_range(struct crash_mem *mem,
 		return 0;
 
 	/* Split happened */
-	if (i == mem->max_nr_ranges - 1)
+	if (mem->nr_ranges >= mem->max_nr_ranges)
 		return -ENOMEM;
 
 	/* Location where new range should go */
-- 
2.43.0