fs: fat: cannot write to subdirectories

fs_fat_write() is not able to write to subdirectories.

Currently if a filepath with a leading slash is passed, the slash is
treated as part of the filename to be created in the root directory.

Strip leading (back-)slashes.

Check that the remaining filename does not contain any illegal characters
(<>:"/\|?*). This way we will throw an error when trying to write to a
subdirectory.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
Heinrich Schuchardt 2018-07-02 02:41:23 +02:00 committed by Alexander Graf
parent 1fcb7ea284
commit 0dc1bfb730

View File

@ -909,9 +909,11 @@ static int do_fat_write(const char *filename, void *buffer, loff_t size,
volume_info volinfo;
fsdata datablock;
fsdata *mydata = &datablock;
int cursect;
int cursect, i;
int ret = -1, name_len;
char l_filename[VFAT_MAXLEN_BYTES];
char bad[2] = " ";
const char illegal[] = "<>:\"/\\|?*";
*actwrite = size;
dir_curclust = 0;
@ -971,6 +973,18 @@ static int do_fat_write(const char *filename, void *buffer, loff_t size,
}
dentptr = (dir_entry *) do_fat_read_at_block;
/* Strip leading (back-)slashes */
while ISDIRDELIM(*filename)
++filename;
/* Check that the filename is valid */
for (i = 0; i < strlen(illegal); ++i) {
*bad = illegal[i];
if (strstr(filename, bad)) {
printf("FAT: illegal filename (%s)\n", filename);
return -1;
}
}
name_len = strlen(filename);
if (name_len >= VFAT_MAXLEN_BYTES)
name_len = VFAT_MAXLEN_BYTES - 1;