diff options
| author | Baoquan He <bhe@redhat.com> | 2017-06-27 14:39:06 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-06-30 08:53:14 +0200 |
| commit | 8eabf42ae5237e6b699aeac687b5b629e3537c8d (patch) | |
| tree | 8c44cf4bae96bf80da05770b0212dff252c27e9e /arch/x86/boot/compressed/kaslr.c | |
| parent | x86/boot/KASLR: Add checking for the offset of kernel virtual address randomi... (diff) | |
| download | linux-8eabf42ae5237e6b699aeac687b5b629e3537c8d.tar.xz linux-8eabf42ae5237e6b699aeac687b5b629e3537c8d.zip | |
x86/boot/KASLR: Fix kexec crash due to 'virt_addr' calculation bug
Kernel text KASLR is separated into physical address and virtual
address randomization. And for virtual address randomization, we
only randomiza to get an offset between 16M and KERNEL_IMAGE_SIZE.
So the initial value of 'virt_addr' should be LOAD_PHYSICAL_ADDR,
but not the original kernel loading address 'output'.
The bug will cause kernel boot failure if kernel is loaded at a different
position than the address, 16M, which is decided at compiled time.
Kexec/kdump is such practical case.
To fix it, just assign LOAD_PHYSICAL_ADDR to virt_addr as initial
value.
Tested-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 8391c73 ("x86/KASLR: Randomize virtual address separately")
Link: http://lkml.kernel.org/r/1498567146-11990-3-git-send-email-bhe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/boot/compressed/kaslr.c')
| -rw-r--r-- | arch/x86/boot/compressed/kaslr.c | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index 54c24f0a43d3..56a7e9201741 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -564,9 +564,6 @@ void choose_random_location(unsigned long input, { unsigned long random_addr, min_addr; - /* By default, keep output position unchanged. */ - *virt_addr = *output; - if (cmdline_find_option_bool("nokaslr")) { warn("KASLR disabled: 'nokaslr' on cmdline."); return; |