[PATCH AUTOSEL 4.14 5/8] proc/vmcore: fix potential memory leak in vmcore_init()

[Sasha Levin]

From: Jianglei Nie <niejianglei2021 at 163.com>

[ Upstream commit 12b9d301ff73122aebd78548fa4c04ca69ed78fe ]

Patch series "Some minor cleanup patches resent".

The first three patches trivial clean up patches.

And for the patch "kexec: replace crash_mem_range with range", I got a
ibm-p9wr ppc64le system to test, it works well.

This patch (of 4):

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() gets some error and
returns a negetive value, the elfcorehdr_addr should be released with
elfcorehdr_free().

Fix it by calling elfcorehdr_free() when parse_crash_elf_headers() fails.

Link: https://lkml.kernel.org/r/20220929042936.22012-1-bhe@redhat.com
Link: https://lkml.kernel.org/r/20220929042936.22012-2-bhe@redhat.com
Signed-off-by: Jianglei Nie <niejianglei2021 at 163.com>
Signed-off-by: Baoquan He <bhe at redhat.com>
Acked-by: Baoquan He <bhe at redhat.com>
Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Cc: Chen Lifu <chenlifu at huawei.com>
Cc: "Eric W . Biederman" <ebiederm at xmission.com>
Cc: Li Chen <lchen at ambarella.com>
Cc: Michael Ellerman <mpe at ellerman.id.au>
Cc: Paul Mackerras <paulus at samba.org>
Cc: Petr Mladek <pmladek at suse.com>
Cc: Russell King <linux at armlinux.org.uk>
Cc: ye xingchen <ye.xingchen at zte.com.cn>
Cc: Zeal Robot <zealci at zte.com.cn>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 fs/proc/vmcore.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index 0bfd71bec7f2..2ed309191d91 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -1177,6 +1177,7 @@ static int __init vmcore_init(void)
 		return rc;
 	rc = parse_crash_elf_headers();
 	if (rc) {
+		elfcorehdr_free(elfcorehdr_addr);
 		pr_warn("Kdump: vmcore not initialized\n");
 		return rc;
 	}
-- 
2.35.1