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From: Steven Price <steven.price@arm.com>
To: Andrew Morton <akpm@linux-foundation.org>,
	Mike Rapoport <rppt@linux.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>,
	linux-kernel@vger.kernel.org, Steven Price <steven.price@arm.com>,
	Mark Rutland <mark.rutland@arm.com>
Subject: [PATCH] initramfs: Don't free a non-existent initrd
Date: Thu, 16 May 2019 15:31:25 +0100
Message-ID: <20190516143125.48948-1-steven.price@arm.com> (raw)

Since 54c7a8916a88 ("initramfs: free initrd memory if opening
/initrd.image fails"), the kernel has unconditionally attempted to free
the initrd even if it doesn't exist. In the non-existent case this
causes a boot-time splat if CONFIG_DEBUG_VIRTUAL is enabled due to a
call to virt_to_phys() with a NULL address.

Instead we should check that the initrd actually exists and only attempt
to free it if it does.

Fixes: 54c7a8916a88 ("initramfs: free initrd memory if opening /initrd.image fails")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
 init/initramfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/init/initramfs.c b/init/initramfs.c
index 435a428c2af1..178130fd61c2 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -669,7 +669,7 @@ static int __init populate_rootfs(void)
 	 * If the initrd region is overlapped with crashkernel reserved region,
 	 * free only memory that is not part of crashkernel region.
 	 */
-	if (!do_retain_initrd && !kexec_free_initrd())
+	if (!do_retain_initrd && initrd_start && !kexec_free_initrd())
 		free_initrd_mem(initrd_start, initrd_end);
 	initrd_start = 0;
 	initrd_end = 0;
-- 
2.20.1


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Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-16 14:31 Steven Price [this message]
2019-05-16 15:11 ` Mike Rapoport

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