KCSAN: data-race in pfifo_fast_dequeue / pfifo_fast

KCSAN: data-race in pfifo_fast_dequeue / pfifo_fast_enqueue
Status: auto-closed as invalid on 2021/03/24 02:52
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 243d, last: 243d

Sample crash report:

==================================================================
BUG: KCSAN: data-race in pfifo_fast_dequeue / pfifo_fast_enqueue

write to 0xffff88810e39b500 of 8 bytes by task 12516 on cpu 0:
 __ptr_ring_discard_one include/linux/ptr_ring.h:280 [inline]
 __ptr_ring_consume include/linux/ptr_ring.h:301 [inline]
 __skb_array_consume include/linux/skb_array.h:98 [inline]
 pfifo_fast_dequeue+0x25f/0x570 net/sched/sch_generic.c:651
 dequeue_skb+0x145/0xf20 net/sched/sch_generic.c:263
 qdisc_restart net/sched/sch_generic.c:366 [inline]
 __qdisc_run+0x72/0x180 net/sched/sch_generic.c:384
 qdisc_run include/net/pkt_sched.h:136 [inline]
 __dev_xmit_skb net/core/dev.c:3765 [inline]
 __dev_queue_xmit+0xa75/0x1570 net/core/dev.c:4119
 dev_queue_xmit+0x13/0x20 net/core/dev.c:4184
 __bpf_tx_skb net/core/filter.c:2116 [inline]
 __bpf_redirect_common net/core/filter.c:2155 [inline]
 __bpf_redirect+0x67c/0x760 net/core/filter.c:2162
 ____bpf_clone_redirect net/core/filter.c:2448 [inline]
 bpf_clone_redirect+0x168/0x1c0 net/core/filter.c:2420
 bpf_prog_79bab0a1566dd526+0x56/0x18c
 bpf_dispatcher_nop_func include/linux/bpf.h:651 [inline]
 bpf_test_run+0x278/0x460 net/bpf/test_run.c:50
 bpf_prog_test_run_skb+0x714/0xe90 net/bpf/test_run.c:582
 bpf_prog_test_run kernel/bpf/syscall.c:3122 [inline]
 __do_sys_bpf+0x3971/0x9950 kernel/bpf/syscall.c:4400
 __se_sys_bpf kernel/bpf/syscall.c:4340 [inline]
 __x64_sys_bpf+0x3d/0x50 kernel/bpf/syscall.c:4340
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88810e39b500 of 8 bytes by task 12512 on cpu 1:
 __ptr_ring_produce include/linux/ptr_ring.h:106 [inline]
 ptr_ring_produce include/linux/ptr_ring.h:129 [inline]
 skb_array_produce include/linux/skb_array.h:44 [inline]
 pfifo_fast_enqueue+0xdd/0x300 net/sched/sch_generic.c:626
 __dev_xmit_skb net/core/dev.c:3764 [inline]
 __dev_queue_xmit+0x785/0x1570 net/core/dev.c:4119
 dev_queue_xmit+0x13/0x20 net/core/dev.c:4184
 __bpf_tx_skb net/core/filter.c:2116 [inline]
 __bpf_redirect_common net/core/filter.c:2155 [inline]
 __bpf_redirect+0x67c/0x760 net/core/filter.c:2162
 ____bpf_clone_redirect net/core/filter.c:2448 [inline]
 bpf_clone_redirect+0x168/0x1c0 net/core/filter.c:2420
 bpf_prog_79bab0a1566dd526+0x56/0x390
 bpf_dispatcher_nop_func include/linux/bpf.h:651 [inline]
 bpf_test_run+0x278/0x460 net/bpf/test_run.c:50
 bpf_prog_test_run_skb+0x714/0xe90 net/bpf/test_run.c:582
 bpf_prog_test_run kernel/bpf/syscall.c:3122 [inline]
 __do_sys_bpf+0x3971/0x9950 kernel/bpf/syscall.c:4400
 __se_sys_bpf kernel/bpf/syscall.c:4340 [inline]
 __x64_sys_bpf+0x3d/0x50 kernel/bpf/syscall.c:4340
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 12512 Comm: syz-executor.2 Not tainted 5.11.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci2-upstream-kcsan-gce	2021/02/17 02:51	upstream	f40ddce88593	98682e5e	.config	log	report			info	KCSAN: data-race in pfifo_fast_dequeue / pfifo_fast_enqueue