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From:   Jianglei Nie <niejianglei2021@163.com>
To:     bhe@redhat.com, vgoyal@redhat.com, dyoung@redhat.com
Cc:     kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-fsdevel@vger.kernel.org,
        Jianglei Nie <niejianglei2021@163.com>
Subject: [PATCH v2] proc/vmcore: fix potential memory leak in vmcore_init()
Date:   Mon,  4 Jul 2022 16:18:39 +0800
Message-Id: <20220704081839.2232996-1-niejianglei2021@163.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

elfcorehdr_alloc() allocates a memory chunk for elfcorehdr_addr with
kzalloc(). If is_vmcore_usable() returns false, elfcorehdr_addr is a
predefined value. If parse_crash_elf_headers() occurs some error and
returns a negetive value, the elfcorehdr_addr should be released with
elfcorehdr_free().

We can fix by calling elfcorehdr_free() when parse_crash_elf_headers()
fails.

Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
---
 fs/proc/vmcore.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index 4eaeb645e759..86887bd90263 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -1569,7 +1569,7 @@ static int __init vmcore_init(void)
 	rc = parse_crash_elf_headers();
 	if (rc) {
 		pr_warn("Kdump: vmcore not initialized\n");
-		return rc;
+		goto fail;
 	}
 	elfcorehdr_free(elfcorehdr_addr);
 	elfcorehdr_addr = ELFCORE_ADDR_ERR;
@@ -1577,6 +1577,9 @@ static int __init vmcore_init(void)
 	proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &vmcore_proc_ops);
 	if (proc_vmcore)
 		proc_vmcore->size = vmcore_size;
+
+fail:
+	elfcorehdr_free(elfcorehdr_addr);
 	return 0;
 }
 fs_initcall(vmcore_init);
-- 
2.25.1