diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0009-x86-KASLR-Fix-kexec-kernel-boot-crash-when-KASLR-ran.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0009-x86-KASLR-Fix-kexec-kernel-boot-crash-when-KASLR-ran.patch | 79 |
1 files changed, 0 insertions, 79 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0009-x86-KASLR-Fix-kexec-kernel-boot-crash-when-KASLR-ran.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0009-x86-KASLR-Fix-kexec-kernel-boot-crash-when-KASLR-ran.patch deleted file mode 100644 index 1e9973e7..00000000 --- a/common/recipes-kernel/linux/linux-yocto-4.9.21/0009-x86-KASLR-Fix-kexec-kernel-boot-crash-when-KASLR-ran.patch +++ /dev/null @@ -1,79 +0,0 @@ -From 29fa51519ae0978980c8fc154eba5b244ad7980f Mon Sep 17 00:00:00 2001 -From: Baoquan He <bhe@redhat.com> -Date: Thu, 27 Apr 2017 15:42:20 +0800 -Subject: [PATCH 09/93] x86/KASLR: Fix kexec kernel boot crash when KASLR - randomization fails - -[ Upstream commit da63b6b20077469bd6bd96e07991ce145fc4fbc4 ] - -Dave found that a kdump kernel with KASLR enabled will reset to the BIOS -immediately if physical randomization failed to find a new position for -the kernel. A kernel with the 'nokaslr' option works in this case. - -The reason is that KASLR will install a new page table for the identity -mapping, while it missed building it for the original kernel location -if KASLR physical randomization fails. - -This only happens in the kexec/kdump kernel, because the identity mapping -has been built for kexec/kdump in the 1st kernel for the whole memory by -calling init_pgtable(). Here if physical randomizaiton fails, it won't build -the identity mapping for the original area of the kernel but change to a -new page table '_pgtable'. Then the kernel will triple fault immediately -caused by no identity mappings. - -The normal kernel won't see this bug, because it comes here via startup_32() -and CR3 will be set to _pgtable already. In startup_32() the identity -mapping is built for the 0~4G area. In KASLR we just append to the existing -area instead of entirely overwriting it for on-demand identity mapping -building. So the identity mapping for the original area of kernel is still -there. - -To fix it we just switch to the new identity mapping page table when physical -KASLR succeeds. Otherwise we keep the old page table unchanged just like -"nokaslr" does. - -Signed-off-by: Baoquan He <bhe@redhat.com> -Signed-off-by: Dave Young <dyoung@redhat.com> -Acked-by: Kees Cook <keescook@chromium.org> -Cc: Borislav Petkov <bp@suse.de> -Cc: Dave Jiang <dave.jiang@intel.com> -Cc: Linus Torvalds <torvalds@linux-foundation.org> -Cc: Peter Zijlstra <peterz@infradead.org> -Cc: Thomas Garnier <thgarnie@google.com> -Cc: Thomas Gleixner <tglx@linutronix.de> -Cc: Yinghai Lu <yinghai@kernel.org> -Link: http://lkml.kernel.org/r/1493278940-5885-1-git-send-email-bhe@redhat.com -Signed-off-by: Ingo Molnar <mingo@kernel.org> -Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> -Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> ---- - arch/x86/boot/compressed/kaslr.c | 11 +++++++++-- - 1 file changed, 9 insertions(+), 2 deletions(-) - -diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c -index a66854d..af42b4d 100644 ---- a/arch/x86/boot/compressed/kaslr.c -+++ b/arch/x86/boot/compressed/kaslr.c -@@ -463,10 +463,17 @@ void choose_random_location(unsigned long input, - add_identity_map(random_addr, output_size); - *output = random_addr; - } -+ -+ /* -+ * This loads the identity mapping page table. -+ * This should only be done if a new physical address -+ * is found for the kernel, otherwise we should keep -+ * the old page table to make it be like the "nokaslr" -+ * case. -+ */ -+ finalize_identity_maps(); - } - -- /* This actually loads the identity pagetable on x86_64. */ -- finalize_identity_maps(); - - /* Pick random virtual address starting from LOAD_PHYSICAL_ADDR. */ - if (IS_ENABLED(CONFIG_X86_64)) --- -2.7.4 - |