===================================================== BUG: KMSAN: uninit-value in kmsan_check_skb+0x3c/0x240 mm/kmsan/kmsan_hooks.c:275 CPU: 1 PID: 5846 Comm: kworker/u4:21 Tainted: G W 5.12.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x24c/0x2e0 lib/dump_stack.c:120 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:121 kmsan_internal_check_memory+0x1f5/0x500 mm/kmsan/kmsan.c:399 kmsan_check_skb+0x3c/0x240 mm/kmsan/kmsan_hooks.c:275 pfifo_fast_dequeue+0x1031/0x1190 net/sched/sch_generic.c:659 dequeue_skb+0x4ad/0x3680 net/sched/sch_generic.c:264 qdisc_restart net/sched/sch_generic.c:367 [inline] __qdisc_run+0x101/0x490 net/sched/sch_generic.c:385 qdisc_run include/net/pkt_sched.h:136 [inline] __dev_xmit_skb net/core/dev.c:3807 [inline] __dev_queue_xmit+0x26ad/0x4600 net/core/dev.c:4162 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4227 batadv_send_skb_packet+0x622/0x970 net/batman-adv/send.c:108 batadv_send_broadcast_skb+0x76/0x90 net/batman-adv/send.c:127 batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:393 [inline] batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:419 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0xb2d/0xef0 net/batman-adv/bat_iv_ogm.c:1711 process_one_work+0x1219/0x1fe0 kernel/workqueue.c:2275 worker_thread+0x10ec/0x2340 kernel/workqueue.c:2421 kthread+0x521/0x560 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:120 [inline] kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:288 kmsan_memcpy_memmove_metadata+0x25e/0x2d0 mm/kmsan/kmsan.c:225 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:245 __msan_memcpy+0x46/0x60 mm/kmsan/kmsan_instr.c:110 pskb_expand_head+0x3d6/0x1e20 net/core/skbuff.c:1685 __skb_cow include/linux/skbuff.h:3232 [inline] skb_cow_head include/linux/skbuff.h:3266 [inline] batadv_skb_head_push+0x2cc/0x410 net/batman-adv/soft-interface.c:73 batadv_send_skb_packet+0x1ed/0x970 net/batman-adv/send.c:86 batadv_send_broadcast_skb+0x76/0x90 net/batman-adv/send.c:127 batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:393 [inline] batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:419 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0xb2d/0xef0 net/batman-adv/bat_iv_ogm.c:1711 process_one_work+0x1219/0x1fe0 kernel/workqueue.c:2275 worker_thread+0x10ec/0x2340 kernel/workqueue.c:2421 kthread+0x521/0x560 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:120 [inline] kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:103 kmsan_slab_alloc+0x8e/0xe0 mm/kmsan/kmsan_hooks.c:76 slab_alloc_node mm/slub.c:2922 [inline] __kmalloc_node_track_caller+0xa4f/0x1470 mm/slub.c:4609 kmalloc_reserve net/core/skbuff.c:353 [inline] __alloc_skb+0x4dd/0xe90 net/core/skbuff.c:424 __netdev_alloc_skb+0x45d/0x810 net/core/skbuff.c:491 __netdev_alloc_skb_ip_align include/linux/skbuff.h:2884 [inline] netdev_alloc_skb_ip_align include/linux/skbuff.h:2894 [inline] batadv_iv_ogm_aggregate_new net/batman-adv/bat_iv_ogm.c:558 [inline] batadv_iv_ogm_queue_add+0x1376/0x1c40 net/batman-adv/bat_iv_ogm.c:670 batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:849 [inline] batadv_iv_ogm_schedule+0x12cd/0x16b0 net/batman-adv/bat_iv_ogm.c:869 batadv_iv_send_outstanding_bat_ogm_packet+0xd6e/0xef0 net/batman-adv/bat_iv_ogm.c:1723 process_one_work+0x1219/0x1fe0 kernel/workqueue.c:2275 worker_thread+0x10ec/0x2340 kernel/workqueue.c:2421 kthread+0x521/0x560 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Bytes 52-53 of 74 are uninitialized Memory access of size 74 starts at ffff8881212a2840 =====================================================