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Commit 6305a0a9 authored by Marcin Slusarz's avatar Marcin Slusarz Committed by Jan Kara
Browse files

udf: fix udf_build_ustr 



udf_build_ustr was broken:

- size == 1:
    dest->u_len = ptr[1 - 1], but at ptr[0] there's cmpID,
    so we created string with wrong length
    it should not happen, so we BUG() it
- size > 1 and size < UDF_NAME_LEN:
    we set u_len correctly, but memcpy copied one needless byte
- size == UDF_NAME_LEN - 1:
    memcpy overwrited u_len - with correct value, but...
- size >= UDF_NAME_LEN:
    we copied UDF_NAME_LEN - 1 bytes, but dest->u_name is array
    of UDF_NAME_LEN - 2 bytes, so we were overwriting u_len with
    character from input string

nobody noticed because all callers set size
to acceptable values (constants within range)

Signed-off-by: default avatarMarcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent 79cfe0ff

fs/udf/unicode.c

+7 −5
Original line number Diff line number Diff line
@@ -48,14 +48,16 @@ int udf_build_ustr(struct ustr *dest, dstring *ptr, int size) 
{

	int usesize;



	if ((!dest) || (!ptr) || (!size))

	if (!dest || !ptr || !size)

		return -1;

	BUG_ON(size < 2);



	memset(dest, 0, sizeof(struct ustr));

	usesize = (size > UDF_NAME_LEN) ? UDF_NAME_LEN : size;

	usesize = min_t(size_t, ptr[size - 1], sizeof(dest->u_name));

	usesize = min(usesize, size - 2);

	dest->u_cmpID = ptr[0];

	dest->u_len = ptr[size - 1];

	memcpy(dest->u_name, ptr + 1, usesize - 1);

	dest->u_len = usesize;

	memcpy(dest->u_name, ptr + 1, usesize);

	memset(dest->u_name + usesize, 0, sizeof(dest->u_name) - usesize);



	return 0;

}