From e59bcdae87ec116dde25da6d725f79fefb253693 Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Tue, 5 Mar 2013 07:40:16 +0000 Subject: [PATCH] efivars: efivarfs_valid_name() should handle pstore syntax commit 123abd76edf56c02a76b46d3d673897177ef067b upstream. Stricter validation was introduced with commit da27a24383b2b ("efivarfs: guid part of filenames are case-insensitive") and commit 47f531e8ba3b ("efivarfs: Validate filenames much more aggressively"), which is necessary for the guid portion of efivarfs filenames, but we don't need to be so strict with the first part, the variable name. The UEFI specification doesn't impose any constraints on variable names other than they be a NULL-terminated string. The above commits caused a regression that resulted in users seeing the following message, $ sudo mount -v /sys/firmware/efi/efivars mount: Cannot allocate memory whenever pstore EFI variables were present in the variable store, since their variable names failed to pass the following check, /* GUID should be right after the first '-' */ if (s - 1 != strchr(str, '-')) as a typical pstore filename is of the form, dump-type0-10-1-. The fix is trivial since the guid portion of the filename is GUID_LEN bytes, we can use (len - GUID_LEN) to ensure the '-' character is where we expect it to be. (The bogus ENOMEM error value will be fixed in a separate patch.) Reported-by: Joseph Yasi Tested-by: Joseph Yasi Reported-by: Lingzhu Xiang Cc: Josh Boyer Cc: Jeremy Kerr Cc: Matthew Garrett Signed-off-by: Matt Fleming Signed-off-by: Greg Kroah-Hartman --- drivers/firmware/efivars.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index bcb201cd7db8..9d8867563c12 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -921,8 +921,8 @@ static bool efivarfs_valid_name(const char *str, int len) if (len < GUID_LEN + 2) return false; - /* GUID should be right after the first '-' */ - if (s - 1 != strchr(str, '-')) + /* GUID must be preceded by a '-' */ + if (*(s - 1) != '-') return false; /* -- 2.39.5