Commit 6305a0a9 authored Feb 04, 2008 by Marcin Slusarz Committed by Jan Kara Apr 17, 2008

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: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: Jan 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;
		}

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