diff options
| author | Andy Lutomirski <luto@kernel.org> | 2016-02-15 08:32:35 -0800 |
|---|---|---|
| committer | Darren Hart <dvhart@linux.intel.com> | 2016-03-23 10:05:45 -0700 |
| commit | b13de7019c1b67f0c1b987fc9fe82fcc371ba1d2 (patch) | |
| tree | c19747a3335a857e84e78d8ff0c3fa956a8876c3 /drivers/platform | |
| parent | a570af4850043260b87fb1b8aa27a4484e648878 (diff) | |
dell-wmi: Clean up hotkey table size check
Checking the table for a minimum size of 7 bytes makes no sense: any valid
hotkey table has a size that's a multiple of 4.
Clean this up: replace the hardcoded header length with a sizeof and
change the check to ignore an empty hotkey table. The only behavior
change is that a 7-byte table (which is nonsensical) will now be
treated as absent instead of as valid but empty.
Reported-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Diffstat (limited to 'drivers/platform')
| -rw-r--r-- | drivers/platform/x86/dell-wmi.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/platform/x86/dell-wmi.c b/drivers/platform/x86/dell-wmi.c index d6ae69e0a787..32808a463325 100644 --- a/drivers/platform/x86/dell-wmi.c +++ b/drivers/platform/x86/dell-wmi.c @@ -351,13 +351,24 @@ static void __init handle_dmi_entry(const struct dmi_header *dm, if (results->err || results->keymap) return; /* We already found the hotkey table. */ - if (dm->type != 0xb2 || dm->length <= 6) + if (dm->type != 0xb2) return; table = container_of(dm, struct dell_bios_hotkey_table, header); - hotkey_num = (table->header.length - 4) / + hotkey_num = (table->header.length - + sizeof(struct dell_bios_hotkey_table)) / sizeof(struct dell_bios_keymap_entry); + if (hotkey_num < 1) { + /* + * Historically, dell-wmi would ignore a DMI entry of + * fewer than 7 bytes. Sizes between 4 and 8 bytes are + * nonsensical (both the header and all entries are 4 + * bytes), so we approximate the old behavior by + * ignoring tables with fewer than one entry. + */ + return; + } keymap = kcalloc(hotkey_num + 1, sizeof(struct key_entry), GFP_KERNEL); if (!keymap) { |