Message-ID: <681387ad.050a0220.14dd7d.0013.GAE@google.com>
Date: Thu, 01 May 2025 07:39:41 -0700
From: syzbot <syzbot+15cc51ab13a8d9e2adfe@...kaller.appspotmail.com>
To: davem@...emloft.net, dsahern@...nel.org, edumazet@...gle.com, 
	horms@...nel.org, kuba@...nel.org, linux-kernel@...r.kernel.org, 
	netdev@...r.kernel.org, pabeni@...hat.com, syzkaller-bugs@...glegroups.com
Subject: [syzbot] [net?] KASAN: global-out-of-bounds Read in __find_rr_leaf (2)

Hello,

syzbot found the following issue on:

HEAD commit:    7a13c14ee59d Merge tag 'for-6.15-rc4-tag' of git://git.ker..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14d5e39b980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=4d6290f49c6ebe48
dashboard link: https://syzkaller.appspot.com/bug?extid=15cc51ab13a8d9e2adfe
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: i386

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-7a13c14e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5fc0ea9b1119/vmlinux-7a13c14e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/cbd619ca4f7e/bzImage-7a13c14e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+15cc51ab13a8d9e2adfe@...kaller.appspotmail.com

==================================================================
BUG: KASAN: global-out-of-bounds in fib6_check_expired include/net/ip6_fib.h:270 [inline]
BUG: KASAN: global-out-of-bounds in __find_rr_leaf+0xbcb/0xe00 net/ipv6/route.c:843
Read of size 4 at addr ffffffff9af7fbc4 by task kworker/3:4/5983

CPU: 3 UID: 0 PID: 5983 Comm: kworker/3:4 Not tainted 6.15.0-rc4-syzkaller-00051-g7a13c14ee59d #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: mld mld_ifc_work
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xc3/0x670 mm/kasan/report.c:521
 kasan_report+0xe0/0x110 mm/kasan/report.c:634
 fib6_check_expired include/net/ip6_fib.h:270 [inline]
 __find_rr_leaf+0xbcb/0xe00 net/ipv6/route.c:843
 find_rr_leaf net/ipv6/route.c:899 [inline]
 rt6_select net/ipv6/route.c:934 [inline]
 fib6_table_lookup+0x7b3/0xa30 net/ipv6/route.c:2230
 ip6_pol_route+0x1cc/0x1230 net/ipv6/route.c:2266
 pol_lookup_func include/net/ip6_fib.h:616 [inline]
 fib6_rule_lookup+0x536/0x720 net/ipv6/fib6_rules.c:120
 ip6_route_input_lookup net/ipv6/route.c:2335 [inline]
 ip6_route_input+0x662/0xc00 net/ipv6/route.c:2631
 ip6_rcv_finish_core.constprop.0+0x1a0/0x5d0 net/ipv6/ip6_input.c:66
 ip6_list_rcv_finish.constprop.0+0x20f/0xb50 net/ipv6/ip6_input.c:130
 ip6_sublist_rcv net/ipv6/ip6_input.c:319 [inline]
 ipv6_list_rcv+0x339/0x450 net/ipv6/ip6_input.c:353
 __netif_receive_skb_list_ptype net/core/dev.c:5930 [inline]
 __netif_receive_skb_list_core+0x556/0x950 net/core/dev.c:5977
 __netif_receive_skb_list net/core/dev.c:6029 [inline]
 netif_receive_skb_list_internal+0x752/0xdb0 net/core/dev.c:6120
 netif_receive_skb_list net/core/dev.c:6172 [inline]
 netif_receive_skb_list+0x4d/0x4b0 net/core/dev.c:6162
 ieee80211_rx_napi+0x384/0x410 net/mac80211/rx.c:5443
 ieee80211_rx include/net/mac80211.h:5179 [inline]
 ieee80211_handle_queued_frames+0xd5/0x130 net/mac80211/main.c:441
 tasklet_action_common+0x281/0x400 kernel/softirq.c:829
 handle_softirqs+0x216/0x8e0 kernel/softirq.c:579
 do_softirq kernel/softirq.c:480 [inline]
 do_softirq+0xb2/0xf0 kernel/softirq.c:467
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:407
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:910 [inline]
 __dev_queue_xmit+0x8ab/0x43e0 net/core/dev.c:4656
 dev_queue_xmit include/linux/netdevice.h:3350 [inline]
 neigh_resolve_output net/core/neighbour.c:1512 [inline]
 neigh_resolve_output+0x53a/0x940 net/core/neighbour.c:1492
 neigh_output include/net/neighbour.h:539 [inline]
 ip6_finish_output2+0xaeb/0x2020 net/ipv6/ip6_output.c:141
 __ip6_finish_output net/ipv6/ip6_output.c:215 [inline]
 ip6_finish_output+0x3f9/0x1360 net/ipv6/ip6_output.c:226
 NF_HOOK_COND include/linux/netfilter.h:303 [inline]
 ip6_output+0x1f9/0x540 net/ipv6/ip6_output.c:247
 dst_output include/net/dst.h:459 [inline]
 NF_HOOK include/linux/netfilter.h:314 [inline]
 NF_HOOK include/linux/netfilter.h:308 [inline]
 mld_sendpack+0x9e9/0x1220 net/ipv6/mcast.c:1868
 mld_send_cr net/ipv6/mcast.c:2169 [inline]
 mld_ifc_work+0x740/0xca0 net/ipv6/mcast.c:2702
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

The buggy address belongs to the variable:
 binder_deferred_list+0x24/0x40

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1af7f
flags: 0xfff00000002000(reserved|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000002000 ffffea00006bdfc8 ffffea00006bdfc8 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner info is not present (never set?)

Memory state around the buggy address:
 ffffffff9af7fa80: f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9 00 f9 f9 f9
 ffffffff9af7fb00: f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9 00 f9 f9 f9
>ffffffff9af7fb80: f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9 00 00 f9 f9
                                           ^
 ffffffff9af7fc00: f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9 00 00 00 00
 ffffffff9af7fc80: 00 00 00 00 00 00 00 00 00 00 00 f9 f9 f9 f9 f9
==================================================================


---
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