syzbot


KASAN: null-ptr-deref Write in fib6_purge_rt

Status: auto-closed as invalid on 2021/07/20 04:23
Reported-by: syzbot+f667201cc49ff981da2c@syzkaller.appspotmail.com
First crash: 1218d, last: 1218d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: null-ptr-deref Write in fib6_purge_rt net 18 1874d 1896d 12/27 fixed on 2019/06/18 17:49
upstream KASAN: null-ptr-deref Write in fib6_purge_rt (2) net 1 1854d 1850d 0/27 auto-closed as invalid on 2019/10/25 08:48
upstream KASAN: slab-use-after-free Write in fib6_purge_rt net 1 241d 241d 26/27 fixed on 2024/02/01 11:10

Sample crash report:
device veth0_macvtap left promiscuous mode
device veth1_vlan left promiscuous mode
device veth0_vlan left promiscuous mode
Bluetooth: hci1: command 0x0406 tx timeout
==================================================================
BUG: KASAN: null-ptr-deref in fib6_drop_pcpu_from net/ipv6/ip6_fib.c:898 [inline]
BUG: KASAN: null-ptr-deref in fib6_purge_rt+0x1ba/0x610 net/ipv6/ip6_fib.c:912
Write of size 8 at addr 00000000000001e2 by task kworker/u4:10/29375

CPU: 0 PID: 29375 Comm: kworker/u4:10 Not tainted 4.19.182-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 kasan_report_error.cold+0x15b/0x1b9 mm/kasan/report.c:352
 kasan_report+0x8f/0xa0 mm/kasan/report.c:412
 fib6_drop_pcpu_from net/ipv6/ip6_fib.c:898 [inline]
 fib6_purge_rt+0x1ba/0x610 net/ipv6/ip6_fib.c:912
 fib6_del_route net/ipv6/ip6_fib.c:1802 [inline]
 fib6_del+0x9d2/0xeb0 net/ipv6/ip6_fib.c:1838
 fib6_clean_node+0x35a/0x560 net/ipv6/ip6_fib.c:1999
 fib6_walk_continue+0x4ff/0x8d0 net/ipv6/ip6_fib.c:1922
 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:1970
 fib6_clean_tree+0xc2/0x100 net/ipv6/ip6_fib.c:2047
 __fib6_clean_all+0x11f/0x2a0 net/ipv6/ip6_fib.c:2063
 rt6_sync_down_dev net/ipv6/route.c:4133 [inline]
 rt6_disable_ip+0xb5/0x700 net/ipv6/route.c:4138
 addrconf_ifdown.isra.0+0xf6/0x1320 net/ipv6/addrconf.c:3664
 addrconf_notify+0x568/0x21f0 net/ipv6/addrconf.c:3589
 notifier_call_chain+0xc0/0x230 kernel/notifier.c:93
 call_netdevice_notifiers net/core/dev.c:1762 [inline]
 dev_close_many+0x323/0x670 net/core/dev.c:1514
 rollback_registered_many+0x2f7/0xe70 net/core/dev.c:8165
 unregister_netdevice_many.part.0+0x1a/0x300 net/core/dev.c:9316
 unregister_netdevice_many net/core/dev.c:9315 [inline]
 default_device_exit_batch+0x2fa/0x3c0 net/core/dev.c:9787
 ops_exit_list+0xf9/0x150 net/core/net_namespace.c:156
 cleanup_net+0x3b4/0x8b0 net/core/net_namespace.c:553
 process_one_work+0x864/0x1570 kernel/workqueue.c:2152
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2295
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/03/22 04:22 linux-4.19.y 125222814e7b bea32f74 .config console log report info ci2-linux-4-19 KASAN: null-ptr-deref Write in fib6_purge_rt
* Struck through repros no longer work on HEAD.