From: Davide Caratti <dcaratti@xxxxxxxxxx>
commit 86735b57c905e775f05de995df35379366b72168 upstream.
Naresh and Eric report several errors (corrupted elements in the dynamic
key hash list), when running tdc.py or syzbot. The error path of
qdisc_alloc() and qdisc_create() frees the qdisc memory, but it forgets
to unregister the lockdep key, thus causing use-after-free like the
following one:
==================================================================
BUG: KASAN: slab-use-after-free in lockdep_register_key+0x5f2/0x700
Read of size 8 at addr ffff88811236f2a8 by task ip/7925
CPU: 26 PID: 7925 Comm: ip Kdump: loaded Not tainted 6.9.0-rc2+ #648
Hardware name: Supermicro SYS-6027R-72RF/X9DRH-7TF/7F/iTF/iF, BIOS 3.0 07/26/2013
Call Trace:
<TASK>
dump_stack_lvl+0x7c/0xc0
print_report+0xc9/0x610
kasan_report+0x89/0xc0
lockdep_register_key+0x5f2/0x700
qdisc_alloc+0x21d/0xb60
qdisc_create_dflt+0x63/0x3c0
attach_one_default_qdisc.constprop.37+0x8e/0x170
dev_activate+0x4bd/0xc30
__dev_open+0x275/0x380
__dev_change_flags+0x3f1/0x570
dev_change_flags+0x7c/0x160
do_setlink+0x1ea1/0x34b0
__rtnl_newlink+0x8c9/0x1510
rtnl_newlink+0x61/0x90
rtnetlink_rcv_msg+0x2f0/0xbc0
netlink_rcv_skb+0x120/0x380
netlink_unicast+0x420/0x630
netlink_sendmsg+0x732/0xbc0
__sock_sendmsg+0x1ea/0x280
____sys_sendmsg+0x5a9/0x990
___sys_sendmsg+0xf1/0x180
__sys_sendmsg+0xd3/0x180
do_syscall_64+0x96/0x180
entry_SYSCALL_64_after_hwframe+0x71/0x79
RIP: 0033:0x7f9503f4fa07
Code: 0a 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b9 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10
RSP: 002b:00007fff6c729068 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000006630c681 RCX: 00007f9503f4fa07
RDX: 0000000000000000 RSI: 00007fff6c7290d0 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000078
R10: 000000000000009b R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff6c729180 R14: 0000000000000000 R15: 000055bf67dd9040
</TASK>
Allocated by task 7745:
kasan_save_stack+0x1c/0x40
kasan_save_track+0x10/0x30
__kasan_kmalloc+0x7b/0x90
__kmalloc_node+0x1ff/0x460
qdisc_alloc+0xae/0xb60
qdisc_create+0xdd/0xfb0
tc_modify_qdisc+0x37e/0x1960
rtnetlink_rcv_msg+0x2f0/0xbc0
netlink_rcv_skb+0x120/0x380
netlink_unicast+0x420/0x630
netlink_sendmsg+0x732/0xbc0
__sock_sendmsg+0x1ea/0x280
____sys_sendmsg+0x5a9/0x990
___sys_sendmsg+0xf1/0x180
__sys_sendmsg+0xd3/0x180
do_syscall_64+0x96/0x180
entry_SYSCALL_64_after_hwframe+0x71/0x79
Freed by task 7745:
kasan_save_stack+0x1c/0x40
kasan_save_track+0x10/0x30
kasan_save_free_info+0x36/0x60
__kasan_slab_free+0xfe/0x180
kfree+0x113/0x380
qdisc_create+0xafb/0xfb0
tc_modify_qdisc+0x37e/0x1960
rtnetlink_rcv_msg+0x2f0/0xbc0
netlink_rcv_skb+0x120/0x380
netlink_unicast+0x420/0x630
netlink_sendmsg+0x732/0xbc0
__sock_sendmsg+0x1ea/0x280
____sys_sendmsg+0x5a9/0x990
___sys_sendmsg+0xf1/0x180
__sys_sendmsg+0xd3/0x180
do_syscall_64+0x96/0x180
entry_SYSCALL_64_after_hwframe+0x71/0x79
Fix this ensuring that lockdep_unregister_key() is called before the
qdisc struct is freed, also in the error path of qdisc_create() and
qdisc_alloc().
Fixes: af0cb3fa3f9e ("net/sched: fix false lockdep warning on qdisc root lock")
Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>
Closes: https://lore.kernel.org/netdev/20240429221706.1492418-1-naresh.kamboju@xxxxxxxxxx/
Signed-off-by: Davide Caratti <dcaratti@xxxxxxxxxx>
Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Reviewed-by: Ido Schimmel <idosch@xxxxxxxxxx>
Tested-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx>
Tested-by: Ido Schimmel <idosch@xxxxxxxxxx>
Link: https://lore.kernel.org/r/2aa1ca0c0a3aa0acc15925c666c777a4b5de553c.1714496886.git.dcaratti@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/sched/sch_api.c | 1 +
net/sched/sch_generic.c | 1 +
2 files changed, 2 insertions(+)
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1389,6 +1389,7 @@ err_out4:
ops->destroy(sch);
qdisc_put_stab(rtnl_dereference(sch->stab));
err_out3:
+ lockdep_unregister_key(&sch->root_lock_key);
netdev_put(dev, &sch->dev_tracker);
qdisc_free(sch);
err_out2:
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -983,6 +983,7 @@ struct Qdisc *qdisc_alloc(struct netdev_
return sch;
errout1:
+ lockdep_unregister_key(&sch->root_lock_key);
kfree(sch);
errout:
return ERR_PTR(err);
Patches currently in stable-queue which might be from dcaratti@xxxxxxxxxx are
queue-6.9/net-sched-fix-false-lockdep-warning-on-qdisc-root-lo.patch
queue-6.9/net-sched-unregister-lockdep-keys-in-qdisc_create-qdisc_alloc-error-path.patch
