syzbot


KASAN: use-after-free Read in net_tx_action

Status: internal: reported C repro on 2022/08/28 15:01
Reported-by: syzbot+@syzkaller.appspotmail.com
Fix commit: ebda44da44f6 net: sched: fix race condition in qdisc_graft()
Patched on: [ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce ci-upstream-kmsan-gce-386 ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-qemu2-riscv64]
First crash: 162d, last: 117d

Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: WARNING: ODEBUG bug in qdisc_create (log)
Repro: C syz .config

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in net_tx_action+0xc29/0xd20 net/core/dev.c:5061
Read of size 8 at addr ffff88807dab9968 by task ksoftirqd/0/15

CPU: 0 PID: 15 Comm: ksoftirqd/0 Not tainted 6.0.0-rc2-syzkaller-00194-gebe5555c2f34 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:317 [inline]
 print_report.cold+0x2ba/0x719 mm/kasan/report.c:433
 kasan_report+0xb1/0x1e0 mm/kasan/report.c:495
 net_tx_action+0xc29/0xd20 net/core/dev.c:5061
 __do_softirq+0x1d3/0x9c6 kernel/softirq.c:571
 run_ksoftirqd kernel/softirq.c:934 [inline]
 run_ksoftirqd+0x2d/0x60 kernel/softirq.c:926
 smpboot_thread_fn+0x645/0x9c0 kernel/smpboot.c:164
 kthread+0x2e4/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>

Allocated by task 4535:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:437 [inline]
 ____kasan_kmalloc mm/kasan/common.c:516 [inline]
 ____kasan_kmalloc mm/kasan/common.c:475 [inline]
 __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:525
 kmalloc_node include/linux/slab.h:623 [inline]
 kzalloc_node include/linux/slab.h:744 [inline]
 qdisc_alloc+0xb0/0xc50 net/sched/sch_generic.c:938
 qdisc_create.constprop.0+0xce/0x10f0 net/sched/sch_api.c:1211
 tc_modify_qdisc+0x4c5/0x1a00 net/sched/sch_api.c:1660
 rtnetlink_rcv_msg+0x43a/0xca0 net/core/rtnetlink.c:6090
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:734
 ____sys_sendmsg+0x6eb/0x810 net/socket.c:2482
 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536
 __sys_sendmsg+0xf3/0x1c0 net/socket.c:2565
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Freed by task 4535:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track+0x21/0x30 mm/kasan/common.c:45
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
 ____kasan_slab_free mm/kasan/common.c:367 [inline]
 ____kasan_slab_free+0x166/0x1c0 mm/kasan/common.c:329
 kasan_slab_free include/linux/kasan.h:200 [inline]
 slab_free_hook mm/slub.c:1754 [inline]
 slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1780
 slab_free mm/slub.c:3534 [inline]
 kfree+0xe2/0x580 mm/slub.c:4562
 qdisc_create.constprop.0+0xa2f/0x10f0 net/sched/sch_api.c:1296
 tc_modify_qdisc+0x4c5/0x1a00 net/sched/sch_api.c:1660
 rtnetlink_rcv_msg+0x43a/0xca0 net/core/rtnetlink.c:6090
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:734
 ____sys_sendmsg+0x6eb/0x810 net/socket.c:2482
 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536
 __sys_sendmsg+0xf3/0x1c0 net/socket.c:2565
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Last potentially related work creation:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348
 call_rcu+0x99/0x790 kernel/rcu/tree.c:2793
 qdisc_put+0xcd/0xe0 net/sched/sch_generic.c:1083
 taprio_destroy+0x2c0/0x4e0 net/sched/sch_taprio.c:1662
 qdisc_create.constprop.0+0x9c8/0x10f0 net/sched/sch_api.c:1293
 tc_modify_qdisc+0x4c5/0x1a00 net/sched/sch_api.c:1660
 rtnetlink_rcv_msg+0x43a/0xca0 net/core/rtnetlink.c:6090
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:734
 ____sys_sendmsg+0x6eb/0x810 net/socket.c:2482
 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536
 __sys_sendmsg+0xf3/0x1c0 net/socket.c:2565
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Second to last potentially related work creation:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348
 kvfree_call_rcu+0x74/0x940 kernel/rcu/tree.c:3322
 neigh_destroy+0x431/0x630 net/core/neighbour.c:912
 neigh_release include/net/neighbour.h:454 [inline]
 neigh_cleanup_and_release+0x1f8/0x330 net/core/neighbour.c:103
 neigh_periodic_work+0x612/0x9e0 net/core/neighbour.c:994
 process_one_work+0x991/0x1610 kernel/workqueue.c:2289
 worker_thread+0x665/0x1080 kernel/workqueue.c:2436
 kthread+0x2e4/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

The buggy address belongs to the object at ffff88807dab9800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 360 bytes inside of
 1024-byte region [ffff88807dab9800, ffff88807dab9c00)

The buggy address belongs to the physical page:
page:ffffea0001f6ae00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7dab8
head:ffffea0001f6ae00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888011841dc0
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3647, tgid 3647 (syz-executor354), ts 392643261536, free_ts 392419086879
 prep_new_page mm/page_alloc.c:2532 [inline]
 get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283
 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5515
 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2270
 alloc_slab_page mm/slub.c:1824 [inline]
 allocate_slab+0x27e/0x3d0 mm/slub.c:1969
 new_slab mm/slub.c:2029 [inline]
 ___slab_alloc+0x7f1/0xe10 mm/slub.c:3031
 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3118
 slab_alloc_node mm/slub.c:3209 [inline]
 __kmalloc_node+0x2e2/0x380 mm/slub.c:4468
 kmalloc_node include/linux/slab.h:623 [inline]
 kzalloc_node include/linux/slab.h:744 [inline]
 qdisc_alloc+0xb0/0xc50 net/sched/sch_generic.c:938
 qdisc_create_dflt+0x71/0x4a0 net/sched/sch_generic.c:997
 attach_one_default_qdisc net/sched/sch_generic.c:1137 [inline]
 netdev_for_each_tx_queue include/linux/netdevice.h:2437 [inline]
 attach_default_qdiscs net/sched/sch_generic.c:1155 [inline]
 dev_activate+0x760/0xcd0 net/sched/sch_generic.c:1213
 __dev_open+0x393/0x4d0 net/core/dev.c:1441
 __dev_change_flags+0x583/0x750 net/core/dev.c:8556
 dev_change_flags+0x93/0x170 net/core/dev.c:8627
 do_setlink+0x961/0x3bb0 net/core/rtnetlink.c:2780
 __rtnl_newlink+0xd6a/0x17e0 net/core/rtnetlink.c:3546
 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3593
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1449 [inline]
 free_pcp_prepare+0x5e4/0xd20 mm/page_alloc.c:1499
 free_unref_page_prepare mm/page_alloc.c:3380 [inline]
 free_unref_page+0x19/0x4d0 mm/page_alloc.c:3476
 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2548
 qlink_free mm/kasan/quarantine.c:168 [inline]
 qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294
 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:447
 kasan_slab_alloc include/linux/kasan.h:224 [inline]
 slab_post_alloc_hook mm/slab.h:727 [inline]
 slab_alloc_node mm/slub.c:3243 [inline]
 slab_alloc mm/slub.c:3251 [inline]
 kmem_cache_alloc_trace+0x2c0/0x3e0 mm/slub.c:3282
 kmalloc include/linux/slab.h:600 [inline]
 netdevice_queue_work drivers/infiniband/core/roce_gid_mgmt.c:643 [inline]
 netdevice_event+0x1ad/0x8b0 drivers/infiniband/core/roce_gid_mgmt.c:802
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1945
 call_netdevice_notifiers_extack net/core/dev.c:1983 [inline]
 call_netdevice_notifiers net/core/dev.c:1997 [inline]
 dev_set_mac_address+0x2d3/0x3d0 net/core/dev.c:8816
 dev_set_mac_address_user+0x2d/0x50 net/core/dev.c:8830
 do_setlink+0x18c4/0x3bb0 net/core/rtnetlink.c:2735
 __rtnl_newlink+0xd6a/0x17e0 net/core/rtnetlink.c:3546
 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3593
 rtnetlink_rcv_msg+0x43a/0xca0 net/core/rtnetlink.c:6090

Memory state around the buggy address:
 ffff88807dab9800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807dab9880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807dab9900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                          ^
 ffff88807dab9980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807dab9a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci-upstream-net-this-kasan-gce 2022/08/28 17:43 net ebe5555c2f34 07177916 .config console log report syz C KASAN: use-after-free Read in net_tx_action
ci-upstream-net-kasan-gce 2022/08/28 15:00 net-next 53a406803ca5 07177916 .config console log report syz C KASAN: use-after-free Read in net_tx_action
ci-upstream-kasan-gce-selinux-root 2022/10/12 10:25 upstream 55be6084c8e0 16a9c9e0 .config console log report info [disk image] [vmlinux] KASAN: use-after-free Read in net_tx_action
* Struck through repros no longer work on HEAD.