4.4-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 2aa958c99c7fd3162b089a1a56a34a0cdb778de1 ]
Kexec-ing a kernel with "efi=noruntime" on the first kernel's command line causes the following null pointer dereference:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 #PF error: [normal kernel read fault] Call Trace: efi_runtime_map_copy+0x28/0x30 bzImage64_load+0x688/0x872 arch_kexec_kernel_image_load+0x6d/0x70 kimage_file_alloc_init+0x13e/0x220 __x64_sys_kexec_file_load+0x144/0x290 do_syscall_64+0x55/0x1a0 entry_SYSCALL_64_after_hwframe+0x44/0xa9
Just skip the EFI info setup if EFI runtime services are not enabled.
[ bp: Massage commit message. ]
Suggested-by: Dave Young dyoung@redhat.com Signed-off-by: Kairui Song kasong@redhat.com Signed-off-by: Borislav Petkov bp@suse.de Acked-by: Dave Young dyoung@redhat.com Cc: AKASHI Takahiro takahiro.akashi@linaro.org Cc: Andrew Morton akpm@linux-foundation.org Cc: Ard Biesheuvel ard.biesheuvel@linaro.org Cc: bhe@redhat.com Cc: David Howells dhowells@redhat.com Cc: erik.schmauss@intel.com Cc: fanc.fnst@cn.fujitsu.com Cc: "H. Peter Anvin" hpa@zytor.com Cc: Ingo Molnar mingo@redhat.com Cc: kexec@lists.infradead.org Cc: lenb@kernel.org Cc: linux-acpi@vger.kernel.org Cc: Philipp Rudo prudo@linux.vnet.ibm.com Cc: rafael.j.wysocki@intel.com Cc: robert.moore@intel.com Cc: Thomas Gleixner tglx@linutronix.de Cc: x86-ml x86@kernel.org Cc: Yannik Sembritzki yannik@sembritzki.me Link: https://lkml.kernel.org/r/20190118111310.29589-2-kasong@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/kernel/kexec-bzimage64.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c index 0f8a6bbaaa44..0bf17576dd2a 100644 --- a/arch/x86/kernel/kexec-bzimage64.c +++ b/arch/x86/kernel/kexec-bzimage64.c @@ -168,6 +168,9 @@ setup_efi_state(struct boot_params *params, unsigned long params_load_addr, struct efi_info *current_ei = &boot_params.efi_info; struct efi_info *ei = ¶ms->efi_info;
+ if (!efi_enabled(EFI_RUNTIME_SERVICES)) + return 0; + if (!current_ei->efi_memmap_size) return 0;