From: Rik van Riel riel@surriel.com

mainline inclusion from mainline-v5.13-rc1 commit f0362a253606e2031f8d61c74195d4d6556e12a4 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I960AB CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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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@kernel.org Signed-off-by: Rik van Riel riel@surriel.com Suggested-by: Mike Rappoport rppt@kernel.org Link: https://lore.kernel.org/r/20230817135759.0888e5ef@imladris.surriel.com Signed-off-by: Rob Herring robh@kernel.org Conflicts: drivers/of/kexec.c Signed-off-by: GUO Zihua guozihua@huawei.com --- 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 d8231c34e873..2d1fd5587123 100644 --- a/drivers/of/kexec.c +++ b/drivers/of/kexec.c @@ -178,7 +178,8 @@ int ima_free_kexec_buffer(void) if (ret) return ret;

- return memblock_free(addr, size); + memblock_free_late(addr, size); + return 0;

}