===================================================== BUG: KMSAN: uninit-value in kmsan_check_skb+0x3c/0x210 mm/kmsan/kmsan_hooks.c:299 CPU: 1 PID: 15382 Comm: syz-executor.5 Not tainted 5.5.0-rc5-syzkaller #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+0x1c9/0x220 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118 kmsan_internal_check_memory+0x238/0x3d0 mm/kmsan/kmsan.c:423 kmsan_check_skb+0x3c/0x210 mm/kmsan/kmsan_hooks.c:299 pfifo_fast_dequeue+0xdb4/0xfd0 net/sched/sch_generic.c:658 dequeue_skb net/sched/sch_generic.c:264 [inline] qdisc_restart net/sched/sch_generic.c:367 [inline] __qdisc_run+0x3f1/0x3350 net/sched/sch_generic.c:385 __dev_xmit_skb net/core/dev.c:3622 [inline] __dev_queue_xmit+0x1ff5/0x4220 net/core/dev.c:3982 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4046 neigh_hh_output include/net/neighbour.h:499 [inline] neigh_output include/net/neighbour.h:508 [inline] ip6_finish_output2+0x2056/0x2640 net/ipv6/ip6_output.c:116 ip6_fragment+0x24a9/0x3950 net/ipv6/ip6_output.c:860 __ip6_finish_output+0x73a/0x8e0 net/ipv6/ip6_output.c:140 ip6_finish_output+0x166/0x410 net/ipv6/ip6_output.c:152 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x60a/0x770 net/ipv6/ip6_output.c:175 dst_output include/net/dst.h:436 [inline] ip6_local_out+0x164/0x1d0 net/ipv6/output_core.c:179 ip6_send_skb+0xfa/0x390 net/ipv6/ip6_output.c:1795 udp_v6_send_skb+0x181e/0x1e70 net/ipv6/udp.c:1173 udpv6_sendmsg+0x4579/0x4940 net/ipv6/udp.c:1471 inet6_sendmsg+0x276/0x2e0 net/ipv6/af_inet6.c:576 sock_sendmsg_nosec net/socket.c:639 [inline] sock_sendmsg net/socket.c:659 [inline] kernel_sendmsg+0x24a/0x440 net/socket.c:679 sock_no_sendpage+0x235/0x300 net/core/sock.c:2740 kernel_sendpage net/socket.c:3776 [inline] sock_sendpage+0x1e1/0x2c0 net/socket.c:937 pipe_to_sendpage+0x38c/0x4c0 fs/splice.c:458 splice_from_pipe_feed fs/splice.c:512 [inline] __splice_from_pipe+0x539/0xed0 fs/splice.c:636 splice_from_pipe fs/splice.c:671 [inline] generic_splice_sendpage+0x1d5/0x2d0 fs/splice.c:844 do_splice_from fs/splice.c:863 [inline] direct_splice_actor+0x19e/0x200 fs/splice.c:1037 splice_direct_to_actor+0x8a9/0x11d0 fs/splice.c:992 do_splice_direct+0x342/0x580 fs/splice.c:1080 do_sendfile+0xff5/0x1d10 fs/read_write.c:1464 __do_sys_sendfile64 fs/read_write.c:1525 [inline] __se_sys_sendfile64+0x2bb/0x360 fs/read_write.c:1511 __x64_sys_sendfile64+0x56/0x70 fs/read_write.c:1511 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45c6c9 Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f1a5df28c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f1a5df296d4 RCX: 000000000045c6c9 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000a808 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008cf R14: 00000000004cb5ce R15: 000000000076bf2c Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:310 kmsan_memcpy_memmove_metadata+0x272/0x2e0 mm/kmsan/kmsan.c:247 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:267 __msan_memcpy+0x43/0x50 mm/kmsan/kmsan_instr.c:116 pskb_expand_head+0x38b/0x1b00 net/core/skbuff.c:1637 __skb_cow include/linux/skbuff.h:3120 [inline] skb_cow_head include/linux/skbuff.h:3154 [inline] batadv_skb_head_push+0x234/0x350 net/batman-adv/soft-interface.c:74 batadv_send_skb_packet+0x1a7/0x8c0 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+0x97e/0xd50 net/batman-adv/bat_iv_ogm.c:1706 process_one_work+0x1552/0x1ef0 kernel/workqueue.c:2264 worker_thread+0xef6/0x2450 kernel/workqueue.c:2410 kthread+0x4b5/0x4f0 kernel/kthread.c:256 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:353 Uninit was created at: kmsan_save_stack_with_flags+0x3c/0x90 mm/kmsan/kmsan.c:144 kmsan_internal_alloc_meta_for_pages mm/kmsan/kmsan_shadow.c:307 [inline] kmsan_alloc_page+0x12a/0x310 mm/kmsan/kmsan_shadow.c:336 __alloc_pages_nodemask+0x57f2/0x5f60 mm/page_alloc.c:4800 __alloc_pages include/linux/gfp.h:498 [inline] __alloc_pages_node include/linux/gfp.h:511 [inline] alloc_pages_node include/linux/gfp.h:525 [inline] __page_frag_cache_refill mm/page_alloc.c:4875 [inline] page_frag_alloc+0x3ae/0x910 mm/page_alloc.c:4905 __netdev_alloc_skb+0x703/0xbb0 net/core/skbuff.c:455 __netdev_alloc_skb_ip_align include/linux/skbuff.h:2801 [inline] netdev_alloc_skb_ip_align include/linux/skbuff.h:2811 [inline] batadv_iv_ogm_aggregate_new net/batman-adv/bat_iv_ogm.c:558 [inline] batadv_iv_ogm_queue_add+0x10da/0x1900 net/batman-adv/bat_iv_ogm.c:670 batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:829 [inline] batadv_iv_ogm_schedule+0xcf1/0x13c0 net/batman-adv/bat_iv_ogm.c:865 batadv_iv_send_outstanding_bat_ogm_packet+0xbae/0xd50 net/batman-adv/bat_iv_ogm.c:1718 process_one_work+0x1552/0x1ef0 kernel/workqueue.c:2264 worker_thread+0xef6/0x2450 kernel/workqueue.c:2410 kthread+0x4b5/0x4f0 kernel/kthread.c:256 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:353 Bytes 52-53 of 74 are uninitialized Memory access of size 74 starts at ffff8ac053b92040 =====================================================