KASAN: use-after-free Read in tc_chain_fill_node

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 58fce206 Linux 4.19.78
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14623693600000
kernel config: https://syzkaller.appspot.com/x/.config?x=385b97bfadb400be
dashboard link: https://syzkaller.appspot.com/bug?extid=5f229e48cccc804062c0
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

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

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+5f229e...@syzkaller.appspotmail.com

SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
sclass=netlink_route_socket pig=19989 comm=syz-executor.1
hfs: unable to parse mount options
==================================================================
BUG: KASAN: use-after-free in tc_chain_fill_node+0x891/0x8b0
net/sched/cls_api.c:1733
Read of size 8 at addr ffff8880468ecac0 by task syz-executor.1/19983

CPU: 1 PID: 19983 Comm: syz-executor.1 Not tainted 4.19.78 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x172/0x1f0 lib/dump_stack.c:113
print_address_description.cold+0x7c/0x20d mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report mm/kasan/report.c:412 [inline]
kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:396
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
tc_chain_fill_node+0x891/0x8b0 net/sched/cls_api.c:1733
tc_chain_notify+0x102/0x200 net/sched/cls_api.c:1771
__tcf_chain_put+0x380/0x500 net/sched/cls_api.c:330
tcf_chain_put net/sched/cls_api.c:340 [inline]
tc_ctl_chain+0xbca/0xff0 net/sched/cls_api.c:1932
rtnetlink_rcv_msg+0x463/0xb00 net/core/rtnetlink.c:4747
netlink_rcv_skb+0x17d/0x460 net/netlink/af_netlink.c:2454
rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:4765
netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
netlink_unicast+0x537/0x720 net/netlink/af_netlink.c:1343
netlink_sendmsg+0x8ae/0xd70 net/netlink/af_netlink.c:1908
sock_sendmsg_nosec net/socket.c:622 [inline]
sock_sendmsg+0xd7/0x130 net/socket.c:632
___sys_sendmsg+0x803/0x920 net/socket.c:2115
__sys_sendmsg+0x105/0x1d0 net/socket.c:2153
__do_sys_sendmsg net/socket.c:2162 [inline]
__se_sys_sendmsg net/socket.c:2160 [inline]
__x64_sys_sendmsg+0x78/0xb0 net/socket.c:2160
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459a59
Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff
ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fec9bb8ec78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459a59
RDX: 0000000000000000 RSI: 0000000020000300 RDI: 0000000000000004
RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fec9bb8f6d4
R13: 00000000004c7be6 R14: 00000000004dd980 R15: 00000000ffffffff

Allocated by task 19975:
save_stack+0x45/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
kasan_kmalloc mm/kasan/kasan.c:553 [inline]
kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:531
__do_kmalloc_node mm/slab.c:3689 [inline]
__kmalloc_node+0x51/0x80 mm/slab.c:3696
kmalloc_node include/linux/slab.h:557 [inline]
kzalloc_node include/linux/slab.h:720 [inline]
qdisc_alloc+0xbb/0xa60 net/sched/sch_generic.c:824
qdisc_create+0xec/0x1230 net/sched/sch_api.c:1113
tc_modify_qdisc+0xab0/0x1bdc net/sched/sch_api.c:1554
rtnetlink_rcv_msg+0x463/0xb00 net/core/rtnetlink.c:4747
netlink_rcv_skb+0x17d/0x460 net/netlink/af_netlink.c:2454
rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:4765
netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
netlink_unicast+0x537/0x720 net/netlink/af_netlink.c:1343
netlink_sendmsg+0x8ae/0xd70 net/netlink/af_netlink.c:1908
sock_sendmsg_nosec net/socket.c:622 [inline]
sock_sendmsg+0xd7/0x130 net/socket.c:632
___sys_sendmsg+0x803/0x920 net/socket.c:2115
__sys_sendmsg+0x105/0x1d0 net/socket.c:2153
__do_sys_sendmsg net/socket.c:2162 [inline]
__se_sys_sendmsg net/socket.c:2160 [inline]
__x64_sys_sendmsg+0x78/0xb0 net/socket.c:2160
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 20024:
save_stack+0x45/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
__kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
__cache_free mm/slab.c:3503 [inline]
kfree+0xcf/0x220 mm/slab.c:3822
qdisc_free+0x89/0x100 net/sched/sch_generic.c:945
qdisc_destroy+0x4cf/0x690 net/sched/sch_generic.c:985
notify_and_destroy+0xa2/0xb0 net/sched/sch_api.c:924
qdisc_graft+0x4f3/0x1030 net/sched/sch_api.c:991
tc_modify_qdisc+0xcae/0x1bdc net/sched/sch_api.c:1582
rtnetlink_rcv_msg+0x463/0xb00 net/core/rtnetlink.c:4747
netlink_rcv_skb+0x17d/0x460 net/netlink/af_netlink.c:2454
rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:4765
netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
netlink_unicast+0x537/0x720 net/netlink/af_netlink.c:1343
netlink_sendmsg+0x8ae/0xd70 net/netlink/af_netlink.c:1908
sock_sendmsg_nosec net/socket.c:622 [inline]
sock_sendmsg+0xd7/0x130 net/socket.c:632
___sys_sendmsg+0x803/0x920 net/socket.c:2115
__sys_sendmsg+0x105/0x1d0 net/socket.c:2153
__do_sys_sendmsg net/socket.c:2162 [inline]
__se_sys_sendmsg net/socket.c:2160 [inline]
__x64_sys_sendmsg+0x78/0xb0 net/socket.c:2160
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8880468eca80
which belongs to the cache kmalloc-4096 of size 4096
The buggy address is located 64 bytes inside of
4096-byte region [ffff8880468eca80, ffff8880468eda80)
The buggy address belongs to the page:
page:ffffea00011a3b00 count:1 mapcount:0 mapping:ffff88812c3f0dc0 index:0x0
compound_mapcount: 0
flags: 0x1fffc0000008100(slab|head)
raw: 01fffc0000008100 ffffea00021c2108 ffffea0001311e88 ffff88812c3f0dc0
raw: 0000000000000000 ffff8880468eca80 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff8880468ec980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8880468eca00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> ffff8880468eca80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880468ecb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880468ecb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit: dafd6344 Linux 4.19.79
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1048dde7600000
kernel config: https://syzkaller.appspot.com/x/.config?x=f825f73d8fea6b52

dashboard link: https://syzkaller.appspot.com/bug?extid=5f229e48cccc804062c0
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1012b74f600000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12b7df4f600000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+5f229e...@syzkaller.appspotmail.com

bridge0: port 1(bridge_slave_0) entered disabled state
bond0 (unregistering): Releasing backup interface bond_slave_0
bond0 (unregistering): Releasing backup interface bond_slave_1
bond0 (unregistering): Released all slaves

==================================================================
BUG: KASAN: use-after-free in tc_chain_fill_node+0x891/0x8b0
net/sched/cls_api.c:1733

Read of size 8 at addr ffff888081309200 by task syz-executor778/7720

CPU: 0 PID: 7720 Comm: syz-executor778 Not tainted 4.19.79 #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x172/0x1f0 lib/dump_stack.c:113
print_address_description.cold+0x7c/0x20d mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report mm/kasan/report.c:412 [inline]
kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:396
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
tc_chain_fill_node+0x891/0x8b0 net/sched/cls_api.c:1733
tc_chain_notify+0x102/0x200 net/sched/cls_api.c:1771
__tcf_chain_put+0x380/0x500 net/sched/cls_api.c:330
tcf_chain_put net/sched/cls_api.c:340 [inline]

tc_new_tfilter+0xdae/0x1790 net/sched/cls_api.c:1338

rtnetlink_rcv_msg+0x463/0xb00 net/core/rtnetlink.c:4747
netlink_rcv_skb+0x17d/0x460 net/netlink/af_netlink.c:2454
rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:4765
netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
netlink_unicast+0x537/0x720 net/netlink/af_netlink.c:1343
netlink_sendmsg+0x8ae/0xd70 net/netlink/af_netlink.c:1908
sock_sendmsg_nosec net/socket.c:622 [inline]
sock_sendmsg+0xd7/0x130 net/socket.c:632
___sys_sendmsg+0x803/0x920 net/socket.c:2115
__sys_sendmsg+0x105/0x1d0 net/socket.c:2153
__do_sys_sendmsg net/socket.c:2162 [inline]
__se_sys_sendmsg net/socket.c:2160 [inline]
__x64_sys_sendmsg+0x78/0xb0 net/socket.c:2160
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe

RIP: 0033:0x447cc9
Code: e8 8c e7 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7

48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff

ff 0f 83 fb 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f4aee95bd98 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000006ddc78 RCX: 0000000000447cc9
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000006
RBP: 00000000006ddc70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006ddc7c
R13: 0000000000000000 R14: 0000000000000000 R15: 0507002400000074

Allocated by task 7713:

save_stack+0x45/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
kasan_kmalloc mm/kasan/kasan.c:553 [inline]
kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:531
__do_kmalloc_node mm/slab.c:3689 [inline]
__kmalloc_node+0x51/0x80 mm/slab.c:3696
kmalloc_node include/linux/slab.h:557 [inline]
kzalloc_node include/linux/slab.h:720 [inline]
qdisc_alloc+0xbb/0xa60 net/sched/sch_generic.c:824
qdisc_create+0xec/0x1230 net/sched/sch_api.c:1113

tc_modify_qdisc+0x51b/0x1bdc net/sched/sch_api.c:1571

rtnetlink_rcv_msg+0x463/0xb00 net/core/rtnetlink.c:4747
netlink_rcv_skb+0x17d/0x460 net/netlink/af_netlink.c:2454
rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:4765
netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
netlink_unicast+0x537/0x720 net/netlink/af_netlink.c:1343
netlink_sendmsg+0x8ae/0xd70 net/netlink/af_netlink.c:1908
sock_sendmsg_nosec net/socket.c:622 [inline]
sock_sendmsg+0xd7/0x130 net/socket.c:632
___sys_sendmsg+0x803/0x920 net/socket.c:2115
__sys_sendmsg+0x105/0x1d0 net/socket.c:2153
__do_sys_sendmsg net/socket.c:2162 [inline]
__se_sys_sendmsg net/socket.c:2160 [inline]
__x64_sys_sendmsg+0x78/0xb0 net/socket.c:2160
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 7723:

save_stack+0x45/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
__kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
__cache_free mm/slab.c:3503 [inline]
kfree+0xcf/0x220 mm/slab.c:3822
qdisc_free+0x89/0x100 net/sched/sch_generic.c:945
qdisc_destroy+0x4cf/0x690 net/sched/sch_generic.c:985

dev_shutdown+0x2c5/0x497 net/sched/sch_generic.c:1290
rollback_registered_many+0x6f9/0xda0 net/core/dev.c:7998
unregister_netdevice_many.part.0+0x1b/0x1f0 net/core/dev.c:9115
unregister_netdevice_many+0x3b/0x50 net/core/dev.c:9114
rtnl_delete_link+0xda/0x130 net/core/rtnetlink.c:2739
rtnl_dellink+0x3a7/0x920 net/core/rtnetlink.c:2793

rtnetlink_rcv_msg+0x463/0xb00 net/core/rtnetlink.c:4747
netlink_rcv_skb+0x17d/0x460 net/netlink/af_netlink.c:2454
rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:4765
netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
netlink_unicast+0x537/0x720 net/netlink/af_netlink.c:1343
netlink_sendmsg+0x8ae/0xd70 net/netlink/af_netlink.c:1908
sock_sendmsg_nosec net/socket.c:622 [inline]
sock_sendmsg+0xd7/0x130 net/socket.c:632
___sys_sendmsg+0x803/0x920 net/socket.c:2115
__sys_sendmsg+0x105/0x1d0 net/socket.c:2153
__do_sys_sendmsg net/socket.c:2162 [inline]
__se_sys_sendmsg net/socket.c:2160 [inline]
__x64_sys_sendmsg+0x78/0xb0 net/socket.c:2160
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8880813091c0
which belongs to the cache kmalloc-2048 of size 2048

The buggy address is located 64 bytes inside of

2048-byte region [ffff8880813091c0, ffff8880813099c0)

The buggy address belongs to the page:

page:ffffea000204c200 count:1 mapcount:0 mapping:ffff88812c3f0c40 index:0x0

compound_mapcount: 0
flags: 0x1fffc0000008100(slab|head)

raw: 01fffc0000008100 ffffea000257a488 ffffea000262a688 ffff88812c3f0c40
raw: 0000000000000000 ffff8880813080c0 0000000100000003 0000000000000000

page dumped because: kasan: bad access detected

Memory state around the buggy address:

ffff888081309100: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff888081309180: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
> ffff888081309200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888081309280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888081309300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

[syzbot]

This bug is marked as fixed by commit:
net: core: netlink: add helper refcount dec and lock function
net: sched: add helper function to take reference to Qdisc
net: sched: extend Qdisc with rcu
net: sched: rename qdisc_destroy() to qdisc_put()
net: sched: use Qdisc rcu API instead of relying on rtnl lock
But I can't find it in any tested tree for more than 90 days.
Is it a correct commit? Please update it by replying:
#syz fix: exact-commit-title
Until then the bug is still considered open and
new crashes with the same signature are ignored.

[syzbot]

[syzbot]

[syzbot]

[syzbot]

[syzbot]

[syzbot]

[syzbot]

[syzbot]

[syzbot]

[syzbot]

[syzbot]

[syzbot]

[syzbot]

[syzbot]

[syzbot]

[syzbot]

[syzbot]

[syzbot]

[syzbot]

[syzbot]

Dashboard link: https://syzkaller.appspot.com/bug?extid=5f229e48cccc804062c0

[syzbot]

This bug is marked as fixed by commit:
net: core: netlink: add helper refcount dec and lock function
net: sched: add helper function to take reference to Qdisc
net: sched: extend Qdisc with rcu
net: sched: rename qdisc_destroy() to qdisc_put()
net: sched: use Qdisc rcu API instead of relying on rtnl lock

But I can't find it in the tested trees[1] for more than 90 days.

Is it a correct commit? Please update it by replying:

#syz fix: exact-commit-title

Until then the bug is still considered open and new crashes with
the same signature are ignored.

Kernel: Linux 4.19
Dashboard link: https://syzkaller.appspot.com/bug?extid=5f229e48cccc804062c0

---
[1] I expect the commit to be present in:

1. linux-4.19.y branch of
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git

[syzbot]

[syzbot]

[syzbot]

[syzbot]

[syzbot]

[syzbot]

[syzbot]