Messages in this thread | | | Date | Sun, 24 Jun 2007 16:00:14 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] Avoid potential NULL deref in scripts/genksyms/lex.l |
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On Mon, 25 Jun 2007 00:02:03 +0200 "Jesper Juhl" <jesper.juhl@gmail.com> wrote:
> > > + if (!file || !e) > > > + exit(1); > > > *e = '\0'; > > > cur_filename = memcpy(xmalloc(e-file+1), file, e-file+1); > > > cur_line = atoi(yytext+2); > > > > I don't think the bug which you're fixing can occur: > > > > ^#[ \t]+{INT}[ \t]+\"[^\"\n]+\".*\n return FILENAME; > > > > has anyone reported crashes in there? > > > > It may indeed not be possible. Found by inspection, not by any actual > observed crashes. > But does it really hurt to be defensive here? In case it can somehow > be caused to fail, with my patch it'll fail a bit nicer :) It's not > like it's at all speed critical code that will be hurt by that extra > 'if'...
We can only get NULL pointers here if the regexp is wrong or if there's a bug in the regexp parser. Getting a coredump at the failure site is much better behaviour than mysteriously exiting. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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