18 Jan
2022
18 Jan
'22
6:56 a.m.
On Thu, Dec 30, 2021 at 05:26:49PM +0300, Pavel Skripkin wrote:
Syzbot has reported GPF in sg_alloc_append_table_from_pages(). The problem was in ubuf->pages == ZERO_PTR.
ubuf->pagecount is calculated from arguments passed from user-space. If user creates udmabuf with list.size == 0 then ubuf->pagecount will be also equal to zero; it causes kmalloc_array() to return ZERO_PTR.
Fix it by validating ubuf->pagecount before passing it to kmalloc_array().
Fixes: fbb0de795078 ("Add udmabuf misc device") Reported-and-tested-by: syzbot+2c56b725ec547fa9cb29@syzkaller.appspotmail.com Signed-off-by: Pavel Skripkin paskripkin@gmail.com
Pushed to drm-misc-next.
thanks, Gerd