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BUG: KASAN: use-after-free in __get_unaligned_cpu32 include/linux/unaligned/packed_struct.h:19 [inline]
BUG: KASAN: use-after-free in mc_hash drivers/net/macvlan.c:255 [inline]
BUG: KASAN: use-after-free in macvlan_broadcast+0x4b9/0x5c0 drivers/net/macvlan.c:281
Read of size 4 at addr ffff8880a9729541 by task syz-executor.0/18180

CPU: 1 PID: 18180 Comm: syz-executor.0 Not tainted 4.14.162-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x142/0x197 lib/dump_stack.c:58
 print_address_description.cold+0x7c/0x1dc mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0xa9/0x2af mm/kasan/report.c:393
 __asan_report_load_n_noabort+0xf/0x20 mm/kasan/report.c:440
 __get_unaligned_cpu32 include/linux/unaligned/packed_struct.h:19 [inline]
 mc_hash drivers/net/macvlan.c:255 [inline]
 macvlan_broadcast+0x4b9/0x5c0 drivers/net/macvlan.c:281
 macvlan_queue_xmit drivers/net/macvlan.c:522 [inline]
 macvlan_start_xmit+0x56b/0x72d drivers/net/macvlan.c:565
 __netdev_start_xmit include/linux/netdevice.h:4038 [inline]
 netdev_start_xmit include/linux/netdevice.h:4047 [inline]
 packet_direct_xmit+0x431/0x640 net/packet/af_packet.c:269
 packet_snd net/packet/af_packet.c:2994 [inline]
 packet_sendmsg+0x1dd4/0x5a60 net/packet/af_packet.c:3019
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xce/0x110 net/socket.c:656
 SYSC_sendto+0x206/0x310 net/socket.c:1763
 SyS_sendto+0x40/0x50 net/socket.c:1731
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45af49
RSP: 002b:00007f3fdd519c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 000000000045af49
RDX: 000000000000000e RSI: 0000000020000080 RDI: 0000000000000003
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3fdd51a6d4
R13: 00000000004ca8a7 R14: 00000000004e3ac0 R15: 00000000ffffffff

Allocated by task 3643:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x45/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc mm/kasan/kasan.c:551 [inline]
 kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:529
 kmem_cache_alloc_trace+0x152/0x790 mm/slab.c:3618
 kmalloc include/linux/slab.h:488 [inline]
 kzalloc include/linux/slab.h:661 [inline]
 kernfs_iop_get_link fs/kernfs/symlink.c:127 [inline]
 kernfs_iop_get_link+0x6a/0x650 fs/kernfs/symlink.c:118
 generic_readlink fs/namei.c:4727 [inline]
 vfs_readlink+0x1ac/0x410 fs/namei.c:4762
 SYSC_readlinkat fs/stat.c:406 [inline]
 SyS_readlinkat fs/stat.c:382 [inline]
 SYSC_readlink fs/stat.c:421 [inline]
 SyS_readlink+0x218/0x290 fs/stat.c:418
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 3643:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x45/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x75/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kfree+0xcc/0x270 mm/slab.c:3815
 kfree_link+0x16/0x20 fs/libfs.c:1070
 do_delayed_call include/linux/delayed_call.h:28 [inline]
 generic_readlink fs/namei.c:4732 [inline]
 vfs_readlink+0x129/0x410 fs/namei.c:4762
 SYSC_readlinkat fs/stat.c:406 [inline]
 SyS_readlinkat fs/stat.c:382 [inline]
 SYSC_readlink fs/stat.c:421 [inline]
 SyS_readlink+0x218/0x290 fs/stat.c:418
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

The buggy address belongs to the object at ffff8880a9728600
 which belongs to the cache kmalloc-4096 of size 4096
The buggy address is located 3905 bytes inside of
 4096-byte region [ffff8880a9728600, ffff8880a9729600)
The buggy address belongs to the page:
page:ffffea0002a5ca00 count:1 mapcount:0 mapping:ffff8880a9728600 index:0x0 compound_mapcount: 0
flags: 0xfffe0000008100(slab|head)
raw: 00fffe0000008100 ffff8880a9728600 0000000000000000 0000000100000001
raw: ffffea0002667f20 ffffea00023bfaa0 ffff8880aa800dc0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a9729400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880a9729480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880a9729500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff8880a9729580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880a9729600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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