fat: allow time_offset to be up to 24 hours

Currently we limit values of time_offset mount option to be between -12
and 12 hours.  However e.g.  zone GMT+12 can have a DST correction on top
which makes the total time difference 13 hours.  Update the checks in
mount option parsing to allow offset of upto 24 hours to allow for unusual
cases.

Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: Volker Kuhlmann <list0570@paradise.net.nz>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jan Kara 2016-01-20 14:59:35 -08:00 committed by Linus Torvalds
parent 2c35dea279
commit a513d86983

View File

@ -1146,7 +1146,12 @@ static int parse_options(struct super_block *sb, char *options, int is_vfat,
case Opt_time_offset:
if (match_int(&args[0], &option))
return -EINVAL;
if (option < -12 * 60 || option > 12 * 60)
/*
* GMT+-12 zones may have DST corrections so at least
* 13 hours difference is needed. Make the limit 24
* just in case someone invents something unusual.
*/
if (option < -24 * 60 || option > 24 * 60)
return -EINVAL;
opts->tz_set = 1;
opts->time_offset = option;