Messages in this thread | | | Date | Sun, 24 Jun 2007 14:58:37 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] Avoid potential NULL deref in scripts/genksyms/lex.l |
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On Sun, 24 Jun 2007 23:40:03 +0200 Jesper Juhl <jesper.juhl@gmail.com> wrote:
> strchr() returns NULL in case the string is not found and if that > happens we risk dereferencing a NULL pointer. It never hurts to > check for that condition and exit normally with an error rather > than crashing. > > (no, the indentation is not according to CodingStyle, it's simply > following whatever else is in that file) > > > Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> > --- > > scripts/genksyms/lex.l | 2 ++ > 1 files changed, 2 insertions(+), 0 deletions(-) > > diff --git a/scripts/genksyms/lex.l b/scripts/genksyms/lex.l > index 5e544a0..28edc0c 100644 > --- a/scripts/genksyms/lex.l > +++ b/scripts/genksyms/lex.l > @@ -154,6 +154,8 @@ repeat: > > file = strchr(yytext, '\"')+1; > e = strchr(file, '\"');
If `file' can be null we'd have oopsed here.
> + 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? - 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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