In order to work with preprocessed dts files more easily, dts will parse
line number information in the form emitted by cpp.
Anton Blanchard (using a fuzzer) reported that including a line number
directive with a nul character (a literal nul in the input file, not a \0
sequence) would cause dtc to SEGV. I spotted several more problems on
examining the code:
* It modified yytext in place which seems to work, but is ugly and I'm
not sure if it's safe on all lex/flex versions
* The regexp used in the lexer to recognize line number information
accepts strings with escape characters, but it won't process these
escapes.
- GNU cpp at least, will generate \ escapes in line number
information, at least with files containing " or \ in the name
This patch reworks the handling of line number information to address
these problems. \ escapes should now be handled directly. nuls in file
names (either with a literal nul in the input file, or with a \0 escape
sequence) are still not permitted, but will now result in a lexical error
rather than a SEGV.
Reported-by: Anton Blanchard <anton@samba.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
David Gibson