linux-kernel - [PATCH] mm,ima,kexec,of: use memblock_free_late from ima_free_kexec

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20230817135759.0888e5ef@imladris.surriel.com>
Date:   Thu, 17 Aug 2023 13:57:59 -0400
From:   Rik van Riel <riel@...riel.com>
To:     linux-kernel@...r.kernel.org
Cc:     kernel-team@...a.com, Rob Herring <robh@...nel.org>,
        Frank Rowand <frowand.list@...il.com>,
        devicetree@...r.kernel.org
Subject: [PATCH] mm,ima,kexec,of: use memblock_free_late from
 ima_free_kexec_buffer

The code calling ima_free_kexec_buffer runs long after the memblock
allocator has already been torn down, potentially resulting in a use
after free in memblock_isolate_range.

With KASAN or KFENCE, this use after free will result in a BUG
from the idle task, and a subsequent kernel panic.

Switch ima_free_kexec_buffer over to memblock_free_late to avoid
that issue.

Fixes: fee3ff99bc67 ("powerpc: Move arch independent ima kexec functions to
drivers/of/kexec.c")
Cc: stable@...nel.org
Signed-off-by: Rik van Riel <riel@...riel.com>
Suggested-by: Mike Rappoport <rppt@...nel.org>
---
 drivers/of/kexec.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
index f26d2ba8a371..68278340cecf 100644
--- a/drivers/of/kexec.c
+++ b/drivers/of/kexec.c
@@ -184,7 +184,8 @@ int __init ima_free_kexec_buffer(void)
 	if (ret)
 		return ret;
 
-	return memblock_phys_free(addr, size);
+	memblock_free_late(addr, size);
+	return 0;
 }
 #endif
 
-- 
2.41.0