Re: [syzbot] [bpf?] [net?] KASAN: slab-use-after-free Read in nla_find

From: Jakub Kicinski
Date: Mon Dec 18 2023 - 18:17:22 EST


On Mon, 18 Dec 2023 06:43:26 -0800 syzbot wrote:
> __dump_stack lib/dump_stack.c:88 [inline]
> dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
> print_address_description mm/kasan/report.c:364 [inline]
> print_report+0xc4/0x620 mm/kasan/report.c:475
> kasan_report+0xda/0x110 mm/kasan/report.c:588
> nla_ok include/net/netlink.h:1230 [inline]
> nla_find+0x120/0x130 lib/nlattr.c:746
> nla_find_nested include/net/netlink.h:1260 [inline]
> ____bpf_skb_get_nlattr_nest net/core/filter.c:209 [inline]

This needs nla_ok() instead of playing with nla_len directly.
Will send a fix soon..