Dear uclibc-ng developers,
We have run a static analysis tool (Klocwork) in uclibc and one of its
checkers (ABV.GENERAL) indicates a potential buffer overflow in
uclibc-ng/src/master/libc/stdio/_vfprintf.c:1045
The problem occurs as an out-of-bounds access to array 'argtype', which
is a member of 'ppfs_t'. This array has length 'MAX_ARGS'. According to
the static analysis tool, the array can be accessed using index 'n' of
value '-1' and '9..254' in the conditional shown below:
// File: uclibc-ng/src/master/libc/stdio/_vfprintf.c:1045
if (_is_equal_or_bigger_arg(ppfs->argtype[n], argtype[i])) {
ppfs->argtype[n] = argtype[i];
}
Triggering an out-of-bounds access for 'n=-1' is relatively simply when
using printf or similar functions (e.g. vfprintf). Such out-of-bounds
access occurs when positional arguments are specified, as in the
following statement:
printf("%1$s", "Hello world!");
Although Klocwork claims that the array might be accessed using indexes
'9..254', we were not able to trigger an out-of-bounds access for
indexes in this range.
Kind regards,
Diego Dias
--
Diego M. Dias, Systems Verification Engineer at Kernkonzept,
diego.d...@kernkonzept.com
Phone: +49 351 41883231
Kernkonzept GmbH at Dresden, Germany, HRB 31129, CEO Dr.-Ing. Michael Hohmuth
_______________________________________________
devel mailing list -- devel@uclibc-ng.org
To unsubscribe send an email to devel-le...@uclibc-ng.org
