Messages in this thread | | | Date | Sun, 17 Sep 2023 10:41:05 +0300 | From | Mike Rapoport <> | Subject | Re: [PATCH] x86,kexec,ima: use memblock_free_late from ima_free_kexec_buffer |
| |
On Fri, Sep 08, 2023 at 11:31:27PM -0400, Rik van Riel wrote: > 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>
Acked-by: Mike Rapoport (IBM) <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 b9145a63da77..b098b1fa2470 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; > -- > 2.41.0 > >
-- Sincerely yours, Mike.
| |