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BUG: KASAN: slab-out-of-bounds in strcmp+0x96/0xb0 lib/string.c:328
Read of size 1 at addr ffff8801db1d69c1 by task syz-executor5/4376

CPU: 1 PID: 4376 Comm: syz-executor5 Not tainted 4.15.0-rc2+ #209
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+0x194/0x257 lib/dump_stack.c:53
 print_address_description+0x73/0x250 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report+0x25b/0x340 mm/kasan/report.c:409
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:427
 strcmp+0x96/0xb0 lib/string.c:328
 security_context_to_sid_core+0x437/0x620 security/selinux/ss/services.c:1420
 security_context_to_sid+0x32/0x40 security/selinux/ss/services.c:1479
 selinux_setprocattr+0x51c/0xb50 security/selinux/hooks.c:5985
 security_setprocattr+0x85/0xc0 security/security.c:1264
 proc_pid_attr_write+0x1e6/0x280 fs/proc/base.c:2545
 __vfs_write+0xef/0x970 fs/read_write.c:480
 __kernel_write+0xfe/0x350 fs/read_write.c:501
 write_pipe_buf+0x175/0x220 fs/splice.c:797
 splice_from_pipe_feed fs/splice.c:502 [inline]
 __splice_from_pipe+0x328/0x730 fs/splice.c:626
 splice_from_pipe+0x1e9/0x330 fs/splice.c:661
 default_file_splice_write+0x40/0x90 fs/splice.c:809
 do_splice_from fs/splice.c:851 [inline]
 direct_splice_actor+0x125/0x180 fs/splice.c:1018
 splice_direct_to_actor+0x2c1/0x820 fs/splice.c:973
 do_splice_direct+0x2a7/0x3d0 fs/splice.c:1061
 do_sendfile+0x5d5/0xe90 fs/read_write.c:1413
 SYSC_sendfile64 fs/read_write.c:1468 [inline]
 SyS_sendfile64+0xbd/0x160 fs/read_write.c:1460
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x4529d9
RSP: 002b:00007fbbe2221c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 00000000004529d9
RDX: 0000000020000000 RSI: 0000000000000013 RDI: 0000000000000013
RBP: 000000000000039b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000212 R12: 00000000006f2728
R13: 00000000ffffffff R14: 00007fbbe22226d4 R15: 0000000000000000

Allocated by task 4376:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
 __do_kmalloc mm/slab.c:3711 [inline]
 __kmalloc_track_caller+0x15e/0x760 mm/slab.c:3726
 memdup_user+0x2c/0x90 mm/util.c:164
 proc_pid_attr_write+0x115/0x280 fs/proc/base.c:2534
 __vfs_write+0xef/0x970 fs/read_write.c:480
 __kernel_write+0xfe/0x350 fs/read_write.c:501
 write_pipe_buf+0x175/0x220 fs/splice.c:797
 splice_from_pipe_feed fs/splice.c:502 [inline]
 __splice_from_pipe+0x328/0x730 fs/splice.c:626
 splice_from_pipe+0x1e9/0x330 fs/splice.c:661
 default_file_splice_write+0x40/0x90 fs/splice.c:809
 do_splice_from fs/splice.c:851 [inline]
 direct_splice_actor+0x125/0x180 fs/splice.c:1018
 splice_direct_to_actor+0x2c1/0x820 fs/splice.c:973
 do_splice_direct+0x2a7/0x3d0 fs/splice.c:1061
 do_sendfile+0x5d5/0xe90 fs/read_write.c:1413
 SYSC_sendfile64 fs/read_write.c:1468 [inline]
 SyS_sendfile64+0xbd/0x160 fs/read_write.c:1460
 entry_SYSCALL_64_fastpath+0x1f/0x96

Freed by task 1:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3491 [inline]
 kfree+0xca/0x250 mm/slab.c:3806
 acpi_os_free include/acpi/platform/aclinuxex.h:96 [inline]
 acpi_ns_get_node_unlocked+0x294/0x2ca drivers/acpi/acpica/nsutils.c:732
 acpi_ns_get_node+0x44/0x62 drivers/acpi/acpica/nsutils.c:772
 acpi_ns_evaluate+0xc8/0x8d3 drivers/acpi/acpica/nseval.c:103
 acpi_ut_evaluate_object+0x122/0x3c4 drivers/acpi/acpica/uteval.c:94
 acpi_ut_execute_power_methods+0xe6/0x1dd drivers/acpi/acpica/uteval.c:322
 acpi_get_object_info+0x59d/0xc6c drivers/acpi/acpica/nsxfname.c:401
 acpi_set_pnp_ids drivers/acpi/scan.c:1246 [inline]
 acpi_init_device_object+0x107b/0x1c10 drivers/acpi/scan.c:1558
 acpi_add_single_object+0x1ca/0x1d80 drivers/acpi/scan.c:1590
 acpi_bus_check_add+0x380/0xa50 drivers/acpi/scan.c:1830
 acpi_ns_walk_namespace+0x1d1/0x31e drivers/acpi/acpica/nswalk.c:270
 acpi_walk_namespace+0xb5/0xef drivers/acpi/acpica/nsxfeval.c:641
 acpi_bus_scan+0x120/0x150 drivers/acpi/scan.c:2011
 acpi_scan_init+0x3ce/0x848 drivers/acpi/scan.c:2168
 acpi_init+0x830/0x8e6 drivers/acpi/bus.c:1228
 do_one_initcall+0x9e/0x330 init/main.c:826
 do_initcall_level init/main.c:892 [inline]
 do_initcalls init/main.c:900 [inline]
 do_basic_setup init/main.c:918 [inline]
 kernel_init_freeable+0x469/0x521 init/main.c:1066
 kernel_init+0x13/0x172 init/main.c:993
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:441

The buggy address belongs to the object at ffff8801db1d69c0
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 1 bytes inside of
 32-byte region [ffff8801db1d69c0, ffff8801db1d69e0)
The buggy address belongs to the page:
page:00000000b5fb7716 count:1 mapcount:0 mapping:0000000008d9f38d index:0xffff8801db1d6fc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801db1d6000 ffff8801db1d6fc1 000000010000003f
raw: ffffea0007608ba0 ffffea00076c4be0 ffff8801db0001c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801db1d6880: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801db1d6900: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8801db1d6980: fb fb fb fb fc fc fc fc 01 fc fc fc fc fc fc fc
                                           ^
 ffff8801db1d6a00: fb fb fb fb fc fc fc fc 00 00 03 fc fc fc fc fc
 ffff8801db1d6a80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
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