Messages in this thread Patch in this message | | | Date | Mon, 18 Sep 2023 07:30:23 -0000 | From | "tip-bot2 for Rik van Riel" <> | Subject | [tip: x86/urgent] x86/mm, kexec, ima: Use memblock_free_late() from ima_free_kexec_buffer() |
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The following commit has been merged into the x86/urgent branch of tip:
Commit-ID: 34cf99c250d5cd2530b93a57b0de31d3aaf8685b Gitweb: https://git.kernel.org/tip/34cf99c250d5cd2530b93a57b0de31d3aaf8685b Author: Rik van Riel <riel@surriel.com> AuthorDate: Thu, 17 Aug 2023 13:55:58 -04:00 Committer: Ingo Molnar <mingo@kernel.org> CommitterDate: Mon, 18 Sep 2023 09:24:15 +02:00
x86/mm, kexec, ima: 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 bug.
Fixes: fee3ff99bc67 ("powerpc: Move arch independent ima kexec functions to drivers/of/kexec.c") Suggested-by: Mike Rappoport <rppt@kernel.org> Signed-off-by: Rik van Riel <riel@surriel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230817135558.67274c83@imladris.surriel.com --- arch/x86/kernel/setup.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index b9145a6..b098b1f 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -358,15 +358,11 @@ static void __init add_early_ima_buffer(u64 phys_addr) #if defined(CONFIG_HAVE_IMA_KEXEC) && !defined(CONFIG_OF_FLATTREE) int __init ima_free_kexec_buffer(void) { - int rc; - if (!ima_kexec_buffer_size) return -ENOENT; - rc = memblock_phys_free(ima_kexec_buffer_phys, - ima_kexec_buffer_size); - if (rc) - return rc; + memblock_free_late(ima_kexec_buffer_phys, + ima_kexec_buffer_size); ima_kexec_buffer_phys = 0; ima_kexec_buffer_size = 0;
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