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BUG: KMSAN: kernel-infoleak in kmsan_copy_to_user+0x9c/0xb0 mm/kmsan/kmsan_hooks.c:249
CPU: 1 PID: 13095 Comm: syz-executor.5 Not tainted 5.10.0-rc4-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+0x21c/0x280 lib/dump_stack.c:118
 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:118
 kmsan_internal_check_memory+0x202/0x520 mm/kmsan/kmsan.c:402
 kmsan_copy_to_user+0x9c/0xb0 mm/kmsan/kmsan_hooks.c:249
 instrument_copy_to_user include/linux/instrumented.h:121 [inline]
 copyout lib/iov_iter.c:147 [inline]
 _copy_to_iter+0x637/0x2ed0 lib/iov_iter.c:638
 copy_to_iter include/linux/uio.h:137 [inline]
 simple_copy_to_iter+0xf6/0x150 net/core/datagram.c:519
 __skb_datagram_iter+0x2cb/0x1210 net/core/datagram.c:425
 skb_copy_datagram_iter+0xd8/0x200 net/core/datagram.c:533
 skb_copy_datagram_msg include/linux/skbuff.h:3532 [inline]
 packet_recvmsg+0x764/0x2060 net/packet/af_packet.c:3391
 ____sys_recvmsg+0x57f/0xd50 net/socket.c:885
 ___sys_recvmsg net/socket.c:2618 [inline]
 do_recvmmsg+0xaa7/0x22f0 net/socket.c:2718
 __sys_recvmmsg net/socket.c:2797 [inline]
 __do_sys_recvmmsg net/socket.c:2820 [inline]
 __se_sys_recvmmsg+0x24a/0x410 net/socket.c:2813
 __x64_sys_recvmmsg+0x62/0x80 net/socket.c:2813
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45e219
Code: 0d b4 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 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f27e2115c68 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e219
RDX: 0000000020004582 RSI: 0000000020004b40 RDI: 0000000000000004
RBP: 000000000119bfd0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 000000000119bf8c
R13: 00000000016afb5f R14: 00007f27e21169c0 R15: 000000000119bf8c

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline]
 kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:289
 kmsan_memcpy_memmove_metadata+0x25e/0x2d0 mm/kmsan/kmsan.c:226
 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:246
 __msan_memcpy+0x46/0x60 mm/kmsan/kmsan_instr.c:110
 pskb_expand_head+0x3d6/0x1e20 net/core/skbuff.c:1631
 __skb_cow include/linux/skbuff.h:3165 [inline]
 skb_cow_head include/linux/skbuff.h:3199 [inline]
 batadv_skb_head_push+0x2cc/0x410 net/batman-adv/soft-interface.c:75
 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:394 [inline]
 batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:420 [inline]
 batadv_iv_send_outstanding_bat_ogm_packet+0xb2d/0xef0 net/batman-adv/bat_iv_ogm.c:1712
 process_one_work+0x1219/0x1fe0 kernel/workqueue.c:2272
 worker_thread+0x123c/0x2730 kernel/workqueue.c:2418
 kthread+0x51c/0x560 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Uninit was created at:
 kmsan_save_stack_with_flags+0x3c/0x90 mm/kmsan/kmsan.c:121
 kmsan_alloc_page+0xd3/0x1f0 mm/kmsan/kmsan_shadow.c:274
 __alloc_pages_nodemask+0x827/0xf90 mm/page_alloc.c:4989
 __alloc_pages include/linux/gfp.h:511 [inline]
 __alloc_pages_node include/linux/gfp.h:524 [inline]
 alloc_pages_node include/linux/gfp.h:538 [inline]
 __page_frag_cache_refill mm/page_alloc.c:5065 [inline]
 page_frag_alloc+0x357/0x890 mm/page_alloc.c:5095
 __netdev_alloc_skb+0xbe2/0xc40 net/core/skbuff.c:456
 __netdev_alloc_skb_ip_align include/linux/skbuff.h:2846 [inline]
 netdev_alloc_skb_ip_align include/linux/skbuff.h:2856 [inline]
 batadv_iv_ogm_aggregate_new net/batman-adv/bat_iv_ogm.c:559 [inline]
 batadv_iv_ogm_queue_add+0x1386/0x1c50 net/batman-adv/bat_iv_ogm.c:671
 batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:834 [inline]
 batadv_iv_ogm_schedule+0xe4e/0x1670 net/batman-adv/bat_iv_ogm.c:870
 batadv_iv_send_outstanding_bat_ogm_packet+0xd6e/0xef0 net/batman-adv/bat_iv_ogm.c:1724
 process_one_work+0x1219/0x1fe0 kernel/workqueue.c:2272
 worker_thread+0x123c/0x2730 kernel/workqueue.c:2418
 kthread+0x51c/0x560 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Bytes 52-53 of 74 are uninitialized
Memory access of size 74 starts at ffff888098695440
Data copied to user address 0000000020003380
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