Messages in this thread Patch in this message | | | Date | Thu, 17 Aug 2023 13:55:58 -0400 | From | Rik van Riel <> | Subject | [PATCH] mm,kexec,ima,x86: 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@kernel.org Signed-off-by: Rik van Riel <riel@surriel.com> Suggested-by: Mike Rappoport <rppt@kernel.org> --- 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 fd975a4a5200..aa0df37c1fe7 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -359,15 +359,11 @@ 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; -- 2.41.0
| |