PF_CAN: dropped non conform CAN skbuf: dev type 65534, len 3, datalen 44
==================================================================
BUG: KMSAN: uninit-value in _copy_to_user+0x12f/0x180 lib/usercopy.c:26
CPU: 1 PID: 4362 Comm: rsyslogd Not tainted 4.17.0+ #8
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+0x185/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x188/0x2a0 mm/kmsan/kmsan.c:1122
 __msan_warning_32+0x70/0xc0 mm/kmsan/kmsan_instr.c:620
 _copy_to_user+0x12f/0x180 lib/usercopy.c:26
 copy_to_user include/linux/uaccess.h:183 [inline]
 syslog_print kernel/printk/printk.c:1344 [inline]
 do_syslog+0x3936/0x3c20 kernel/printk/printk.c:1467
 kmsg_read+0x142/0x1a0 fs/proc/kmsg.c:40
 proc_reg_read+0x1e3/0x2f0 fs/proc/inode.c:230
 __vfs_read+0x1b2/0x9d0 fs/read_write.c:416
 vfs_read+0x36c/0x6b0 fs/read_write.c:452
 ksys_read fs/read_write.c:578 [inline]
 __do_sys_read fs/read_write.c:588 [inline]
 __se_sys_read fs/read_write.c:586 [inline]
 __x64_sys_read+0x1bf/0x3e0 fs/read_write.c:586
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f1f20ded1fd
RSP: 002b:00007f1f1e38ce30 EFLAGS: 00000293 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 000000000219c670 RCX: 00007f1f20ded1fd
RDX: 0000000000000fff RSI: 00007f1f1fbc15a0 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000002187260 R09: 0000000004000001
R10: 0000000000000001 R11: 0000000000000293 R12: 000000000065e420
R13: 00007f1f1e38d9c0 R14: 00007f1f21432040 R15: 0000000000000003

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:279 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:294 [inline]
 kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:686
 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:464
 log_store+0x13fc/0x14b0 kernel/printk/printk.c:641
 log_output kernel/printk/printk.c:1832 [inline]
 vprintk_emit+0xca5/0x1060 kernel/printk/printk.c:1897
 vprintk_default+0x90/0xa0 kernel/printk/printk.c:1955
 vprintk_func+0x517/0x700 kernel/printk/printk_safe.c:379
 printk+0x1e4/0x210 kernel/printk/printk.c:1991
 can_rcv+0x341/0x390 net/can/af_can.c:726
 __netif_receive_skb_core+0x47f3/0x4aa0 net/core/dev.c:4592
 __netif_receive_skb net/core/dev.c:4657 [inline]
 netif_receive_skb_internal+0x49d/0x630 net/core/dev.c:4731
 netif_receive_skb+0x240/0x250 net/core/dev.c:4755
 tun_rx_batched drivers/net/tun.c:1563 [inline]
 tun_get_user+0x6b54/0x7f00 drivers/net/tun.c:1970
 tun_chr_write_iter+0x1d4/0x330 drivers/net/tun.c:1998
 call_write_iter include/linux/fs.h:1784 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x808/0x9f0 fs/read_write.c:487
 vfs_write+0x467/0x8c0 fs/read_write.c:549
 ksys_write fs/read_write.c:598 [inline]
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x1bf/0x3e0 fs/read_write.c:607
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:279 [inline]
 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:189
 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:315
 kmsan_slab_alloc+0x10/0x20 mm/kmsan/kmsan.c:322
 slab_post_alloc_hook mm/slab.h:446 [inline]
 slab_alloc_node mm/slub.c:2753 [inline]
 __kmalloc_node_track_caller+0xb35/0x11b0 mm/slub.c:4395
 __kmalloc_reserve net/core/skbuff.c:138 [inline]
 __alloc_skb+0x2cb/0x9e0 net/core/skbuff.c:206
 alloc_skb include/linux/skbuff.h:988 [inline]
 alloc_skb_with_frags+0x1e6/0xb80 net/core/skbuff.c:5254
 sock_alloc_send_pskb+0xb56/0x11a0 net/core/sock.c:2088
 tun_alloc_skb drivers/net/tun.c:1540 [inline]
 tun_get_user+0x21cf/0x7f00 drivers/net/tun.c:1834
 tun_chr_write_iter+0x1d4/0x330 drivers/net/tun.c:1998
 call_write_iter include/linux/fs.h:1784 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x808/0x9f0 fs/read_write.c:487
 vfs_write+0x467/0x8c0 fs/read_write.c:549
 ksys_write fs/read_write.c:598 [inline]
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x1bf/0x3e0 fs/read_write.c:607
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
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