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| author | Matt Fleming <matt.fleming@intel.com> | 2014-02-13 18:17:54 +0100 |
|---|---|---|
| committer | Matt Fleming <matt.fleming@intel.com> | 2014-02-14 11:07:15 +0100 |
| commit | 09503379dc99535b1bbfa51aa1aeef340f5d82ec (patch) | |
| tree | acb2cc37053b2041522ed7d70bf26ef8fa7e7a66 | |
| parent | x86/efi: Fix 32-bit fallout (diff) | |
| download | linux-09503379dc99535b1bbfa51aa1aeef340f5d82ec.tar.xz linux-09503379dc99535b1bbfa51aa1aeef340f5d82ec.zip | |
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>
| -rw-r--r-- | arch/x86/platform/efi/efi-bgrt.c | 2 |
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; |