lkml.org 
[lkml]   [2008]   [Jan]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 02/10] udf: fix udf_build_ustr
    On Wed 30-01-08 22:03:52, marcin.slusarz@gmail.com wrote:
    > udf_build_ustr was completely broken when
    > size >= UDF_NAME_LEN - 1 or size < 2
    >
    > nobody noticed because all callers set size
    > to acceptable values (constants)
    >
    > Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
    > Cc: Jan Kara <jack@suse.cz>
    > ---
    > fs/udf/unicode.c | 12 ++++++------
    > 1 files changed, 6 insertions(+), 6 deletions(-)
    >
    > diff --git a/fs/udf/unicode.c b/fs/udf/unicode.c
    > index f969617..f4e54e5 100644
    > --- a/fs/udf/unicode.c
    > +++ b/fs/udf/unicode.c
    > @@ -47,16 +47,16 @@ static int udf_char_to_ustr(struct ustr *dest, const uint8_t *src, int strlen)
    > */
    > int udf_build_ustr(struct ustr *dest, dstring *ptr, int size)
    > {
    > - int usesize;
    > + u8 usesize;
    What is the purpose for this? Why not just leave int there? Arithmetics
    is usually best done in ints if that's possible...
    >
    > - if ((!dest) || (!ptr) || (!size))
    > + if (!dest || !ptr || size < 2)
    > return -1;
    >
    > - memset(dest, 0, sizeof(struct ustr));
    > - usesize = (size > UDF_NAME_LEN) ? UDF_NAME_LEN : size;
    > + usesize = min_t(size_t, size - 2, sizeof(dest->u_name));
    > 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);
    Hmm, after parsing what the standard says (ugh), I don't think the code is
    wrong (at least I think you made it incorrect). The caller of
    udf_char_to_ustr() specifies length of the field (not length of the
    string). Now, in the last character of the field is stored the number of
    characters in the string and in the first character of the field is stored
    encoding of the string. So the original code seems correct.

    Honza
    --
    Jan Kara <jack@suse.cz>
    SUSE Labs, CR


    \
     
     \ /
      Last update: 2008-01-31 11:47    [W:0.048 / U:0.948 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site