=====================================================
BUG: KMSAN: kernel-infoleak in kmsan_copy_to_user+0x81/0x90 mm/kmsan/kmsan_hooks.c:253
CPU: 1 PID: 11133 Comm: syz-executor919 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+0xf8/0x1e0 mm/kmsan/kmsan_report.c:118
 kmsan_internal_check_memory+0x179/0x3f0 mm/kmsan/kmsan.c:423
 kmsan_copy_to_user+0x81/0x90 mm/kmsan/kmsan_hooks.c:253
 copyout+0x168/0x1f0 lib/iov_iter.c:145
 _copy_to_iter+0x358/0x2460 lib/iov_iter.c:633
 copy_to_iter include/linux/uio.h:138 [inline]
 simple_copy_to_iter+0xd7/0x130 net/core/datagram.c:515
 __skb_datagram_iter+0x24d/0xee0 net/core/datagram.c:423
 skb_copy_datagram_iter+0x29c/0x2b0 net/core/datagram.c:529
 tun_put_user drivers/net/tun.c:2144 [inline]
 tun_do_read+0x2458/0x2d70 drivers/net/tun.c:2228
 tun_chr_read_iter+0x229/0x460 drivers/net/tun.c:2247
 call_read_iter include/linux/fs.h:1896 [inline]
 new_sync_read fs/read_write.c:414 [inline]
 __vfs_read+0xa67/0xc90 fs/read_write.c:427
 vfs_read+0x359/0x6f0 fs/read_write.c:461
 ksys_read+0x265/0x430 fs/read_write.c:587
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read+0x92/0xb0 fs/read_write.c:595
 __x64_sys_read+0x4a/0x70 fs/read_write.c:595
 do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x402d10
Code: 01 f0 ff ff 0f 83 a0 0d 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d 9d 92 2d 00 00 75 14 b8 00 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 74 0d 00 00 c3 48 83 ec 08 e8 da 02 00 00
RSP: 002b:00007fffa8cd5568 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000402d10
RDX: 00000000000003e8 RSI: 00007fffa8cd5570 RDI: 00000000000000f0
RBP: 0000000000022d97 R08: 0000000000000000 R09: 0000000000000004
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000403fa0 R14: 0000000000000000 R15: 0000000000000000

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_chain_origin+0xc5/0x140 mm/kmsan/kmsan.c:310
 kmsan_memcpy_memmove_metadata+0x25c/0x2e0 mm/kmsan/kmsan.c:247
 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:267
 __msan_memcpy+0x44/0x50 mm/kmsan/kmsan_instr.c:116
 pskb_expand_head+0x383/0x1b00 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+0x23c/0x360 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+0x993/0xd50 net/batman-adv/bat_iv_ogm.c:1706
 process_one_work+0x1572/0x1ef0 kernel/workqueue.c:2264
 worker_thread+0x111b/0x2460 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+0x134/0x310 mm/kmsan/kmsan_shadow.c:336
 __alloc_pages_nodemask+0x1421/0x5fd0 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+0x3c2/0x750 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+0x1107/0x1940 net/batman-adv/bat_iv_ogm.c:670
 batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:845 [inline]
 batadv_iv_ogm_schedule+0x116f/0x13f0 net/batman-adv/bat_iv_ogm.c:865
 batadv_iv_send_outstanding_bat_ogm_packet+0xbc0/0xd50 net/batman-adv/bat_iv_ogm.c:1718
 process_one_work+0x1572/0x1ef0 kernel/workqueue.c:2264
 worker_thread+0x111b/0x2460 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 146 are uninitialized
Memory access of size 146 starts at ffff9333f9ace840
Data copied to user address 00007fffa8cd5570
=====================================================