This is a note to let you know that I've just added the patch titled
mm,ima,kexec,of: use memblock_free_late from ima_free_kexec_buffer
to the 6.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mm-ima-kexec-of-use-memblock_free_late-from-ima_free_kexec_buffer.patch
and it can be found in the queue-6.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From f0362a253606e2031f8d61c74195d4d6556e12a4 Mon Sep 17 00:00:00 2001
From: Rik van Riel <riel@xxxxxxxxxxx>
Date: Thu, 17 Aug 2023 13:57:59 -0400
Subject: mm,ima,kexec,of: use memblock_free_late from ima_free_kexec_buffer
From: Rik van Riel <riel@xxxxxxxxxxx>
commit f0362a253606e2031f8d61c74195d4d6556e12a4 upstream.
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@xxxxxxxxxx
Signed-off-by: Rik van Riel <riel@xxxxxxxxxxx>
Suggested-by: Mike Rappoport <rppt@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230817135759.0888e5ef@xxxxxxxxxxxxxxxxxxxx
Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/of/kexec.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- 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
Patches currently in stable-queue which might be from riel@xxxxxxxxxxx are
queue-6.4/mm-ima-kexec-of-use-memblock_free_late-from-ima_free_kexec_buffer.patch
