jffs2: Fix possible null-pointer dereferences in jffs2_add_frag_to_fragtree()

In jffs2_add_frag_to_fragtree(), there is an if statement on line 223 to
check whether "this" is NULL:
    if (this)

When "this" is NULL, it is used at several places, such as on line 249:
    if (this->node)
and on line 260:
    if (newfrag->ofs > this->ofs)

Thus possible null-pointer dereferences may occur.

To fix these bugs, -EINVAL is returned when "this" is NULL.

These bugs are found by a static analysis tool STCheck written by us.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
This commit is contained in:
Jia-Ju Bai 2019-07-24 10:46:58 +08:00 committed by Richard Weinberger
parent e46131b9fd
commit f2538f9993

View File

@ -226,7 +226,7 @@ static int jffs2_add_frag_to_fragtree(struct jffs2_sb_info *c, struct rb_root *r
lastend = this->ofs + this->size;
} else {
dbg_fragtree2("lookup gave no frag\n");
lastend = 0;
return -EINVAL;
}
/* See if we ran off the end of the fragtree */