diff options
| author | Matt Fleming <matt.fleming@intel.com> | 2013-04-26 10:10:55 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-04-26 08:02:03 -0700 |
| commit | f464246d85d5a5c0fdbf5838b8c58ef59bd82fcc (patch) | |
| tree | e0788b40695dcaa64ef2baa2367639dcdb3f4fc5 | |
| parent | 37b7f3c76595e23257f61bd80b223de8658617ee (diff) | |
efivars: only check for duplicates on the registered list
variable_is_present() accesses '__efivars' directly, but when called via
gsmi_init() Michel reports observing the following crash,
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: variable_is_present+0x55/0x170
Call Trace:
register_efivars+0x106/0x370
gsmi_init+0x2ad/0x3da
do_one_initcall+0x3f/0x170
The reason for the crash is that '__efivars' hasn't been initialised nor
has it been registered with register_efivars() by the time the google
EFI SMI driver runs. The gsmi code uses its own struct efivars, and
therefore, a different variable list. Fix the above crash by passing
the registered struct efivars to variable_is_present(), so that we
traverse the correct list.
Reported-by: Michel Lespinasse <walken@google.com>
Tested-by: Michel Lespinasse <walken@google.com>
Cc: Mike Waychison <mikew@google.com>
Cc: Matthew Garrett <matthew.garrett@nebula.com>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | drivers/firmware/efivars.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 182ce947117..f4baa11d364 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -1628,10 +1628,11 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj, return count; } -static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor) +static bool variable_is_present(struct efivars *efivars, + efi_char16_t *variable_name, + efi_guid_t *vendor) { struct efivar_entry *entry, *n; - struct efivars *efivars = &__efivars; unsigned long strsize1, strsize2; bool found = false; @@ -1703,8 +1704,8 @@ static void efivar_update_sysfs_entries(struct work_struct *work) if (status != EFI_SUCCESS) { break; } else { - if (!variable_is_present(variable_name, - &vendor)) { + if (!variable_is_present(efivars, + variable_name, &vendor)) { found = true; break; } @@ -2008,7 +2009,8 @@ int register_efivars(struct efivars *efivars, * we'll ever see a different variable name, * and may end up looping here forever. */ - if (variable_is_present(variable_name, &vendor_guid)) { + if (variable_is_present(efivars, variable_name, + &vendor_guid)) { dup_variable_bug(variable_name, &vendor_guid, variable_name_size); status = EFI_NOT_FOUND; |