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authorMatt Fleming <matt.fleming@intel.com>2014-02-13 17:17:54 +0000
committerMatt Fleming <matt.fleming@intel.com>2014-02-14 10:07:15 +0000
commit09503379dc99535b1bbfa51aa1aeef340f5d82ec (patch)
treeacb2cc37053b2041522ed7d70bf26ef8fa7e7a66 /arch
parentc55d016f7a930dd1c995336017123b469a8c8f5a (diff)
downloadlinux-stericsson-09503379dc99535b1bbfa51aa1aeef340f5d82ec.tar.gz
x86/efi: Check status field to validate BGRT header
Madper reported seeing the following crash, BUG: unable to handle kernel paging request at ffffffffff340003 IP: [<ffffffff81d85ba4>] efi_bgrt_init+0x9d/0x133 Call Trace: [<ffffffff81d8525d>] efi_late_init+0x9/0xb [<ffffffff81d68f59>] start_kernel+0x436/0x450 [<ffffffff81d6892c>] ? repair_env_string+0x5c/0x5c [<ffffffff81d68120>] ? early_idt_handlers+0x120/0x120 [<ffffffff81d685de>] x86_64_start_reservations+0x2a/0x2c [<ffffffff81d6871e>] x86_64_start_kernel+0x13e/0x14d This is caused because the layout of the ACPI BGRT header on this system doesn't match the definition from the ACPI spec, and so we get a bogus physical address when dereferencing ->image_address in efi_bgrt_init(). Luckily the status field in the BGRT header clearly marks it as invalid, so we can check that field and skip BGRT initialisation. Reported-by: Madper Xie <cxie@redhat.com> Suggested-by: Toshi Kani <toshi.kani@hp.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/platform/efi/efi-bgrt.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/platform/efi/efi-bgrt.c b/arch/x86/platform/efi/efi-bgrt.c
index 4df9591eadad..f15103dff4b4 100644
--- a/arch/x86/platform/efi/efi-bgrt.c
+++ b/arch/x86/platform/efi/efi-bgrt.c
@@ -42,7 +42,7 @@ void __init efi_bgrt_init(void)
if (bgrt_tab->header.length < sizeof(*bgrt_tab))
return;
- if (bgrt_tab->version != 1)
+ if (bgrt_tab->version != 1 || bgrt_tab->status != 1)
return;
if (bgrt_tab->image_type != 0 || !bgrt_tab->image_address)
return;