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 --- v2: use ISDIRDELIM() to identify (back-)slashes --- fs/fat/fat_write.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c index 5ca8fcda73c..c5aee519b79 100644 --- a/fs/fat/fat_write.c +++ b/fs/fat/fat_write.c @@ -908,9 +908,11 @@ 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; @@ -970,6 +972,18 @@ 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;