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BUG: KMSAN: kernel-infoleak in kmsan_copy_to_user+0x81/0x90 mm/kmsan/kmsan_hooks.c:251
CPU: 1 PID: 11496 Comm: syz-executor.1 Not tainted 5.7.0-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+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_copy_to_user+0x81/0x90 mm/kmsan/kmsan_hooks.c:251
 copyout lib/iov_iter.c:145 [inline]
 _copy_to_iter+0x44f/0x2770 lib/iov_iter.c:633
 copy_to_iter include/linux/uio.h:138 [inline]
 simple_copy_to_iter net/core/datagram.c:519 [inline]
 __skb_datagram_iter+0x2bb/0x1220 net/core/datagram.c:425
 skb_copy_datagram_iter+0x292/0x2b0 net/core/datagram.c:533
 skb_copy_datagram_msg include/linux/skbuff.h:3537 [inline]
 packet_recvmsg+0x630/0x1c40 net/packet/af_packet.c:3378
 sock_recvmsg_nosec net/socket.c:886 [inline]
 sock_recvmsg net/socket.c:904 [inline]
 sock_read_iter+0x6ea/0x700 net/socket.c:982
 call_read_iter include/linux/fs.h:1901 [inline]
 new_sync_read fs/read_write.c:415 [inline]
 __vfs_read+0xa64/0xc80 fs/read_write.c:428
 vfs_read+0x341/0x6b0 fs/read_write.c:462
 ksys_read+0x267/0x450 fs/read_write.c:588
 __do_sys_read fs/read_write.c:598 [inline]
 __se_sys_read+0x92/0xb0 fs/read_write.c:596
 __ia32_sys_read+0x4a/0x70 fs/read_write.c:596
 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline]
 do_fast_syscall_32+0x3bf/0x6d0 arch/x86/entry/common.c:398
 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7fefdd9
Code: 90 e8 0b 00 00 00 f3 90 0f ae e8 eb f9 8d 74 26 00 89 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f5da80cc EFLAGS: 00000296 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020000240
RDX: 0000000000000070 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 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+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:1636
 __skb_cow include/linux/skbuff.h:3171 [inline]
 skb_cow_head include/linux/skbuff.h:3205 [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:1710
 process_one_work+0x1555/0x1f40 kernel/workqueue.c:2268
 worker_thread+0xef6/0x2450 kernel/workqueue.c:2414
 kthread+0x4b5/0x4f0 kernel/kthread.c:269
 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:280 [inline]
 kmsan_alloc_page+0xb9/0x180 mm/kmsan/kmsan_shadow.c:304
 __alloc_pages_nodemask+0x56a2/0x5dc0 mm/page_alloc.c:4848
 __alloc_pages include/linux/gfp.h:504 [inline]
 __alloc_pages_node include/linux/gfp.h:517 [inline]
 alloc_pages_node include/linux/gfp.h:531 [inline]
 __page_frag_cache_refill mm/page_alloc.c:4923 [inline]
 page_frag_alloc+0x3ae/0x910 mm/page_alloc.c:4953
 __netdev_alloc_skb+0x703/0xbb0 net/core/skbuff.c:456
 __netdev_alloc_skb_ip_align include/linux/skbuff.h:2852 [inline]
 netdev_alloc_skb_ip_align include/linux/skbuff.h:2862 [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:833 [inline]
 batadv_iv_ogm_schedule+0xd4c/0x1430 net/batman-adv/bat_iv_ogm.c:869
 batadv_iv_send_outstanding_bat_ogm_packet+0xbae/0xd50 net/batman-adv/bat_iv_ogm.c:1722
 process_one_work+0x1555/0x1f40 kernel/workqueue.c:2268
 worker_thread+0xef6/0x2450 kernel/workqueue.c:2414
 kthread+0x4b5/0x4f0 kernel/kthread.c:269
 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 ffff923753036440
Data copied to user address 000000002000024a
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