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BUG: KASAN: slab-out-of-bounds in strlen+0x91/0xa0 lib/string.c:481
isofs_fill_super: bread failed, dev=loop3, iso_blknum=16, block=32
Read of size 1 at addr ffff8801cbb48230 by task syz-executor0/17662

CPU: 1 PID: 17662 Comm: syz-executor0 Not tainted 4.9.96-g71fce1e #10
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff880199b07978 ffffffff81eb0b69 ffffea00072ed200 ffff8801cbb48230
 0000000000000000 ffff8801cbb48230 ffff8801cbb48228 ffff880199b079b0
 ffffffff8156540b ffff8801cbb48230 0000000000000001 0000000000000000
Call Trace:
 [<ffffffff81eb0b69>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb0b69>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8156540b>] print_address_description+0x6c/0x234 mm/kasan/report.c:256
 [<ffffffff81565815>] kasan_report_error mm/kasan/report.c:355 [inline]
 [<ffffffff81565815>] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412
 [<ffffffff81539434>] __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430
 [<ffffffff81ecdeb1>] strlen+0x91/0xa0 lib/string.c:481
 [<ffffffff815a6064>] getname_kernel+0x24/0x340 fs/namei.c:215
 [<ffffffff815a7684>] kern_path_mountpoint+0x24/0x70 fs/namei.c:2754
 [<ffffffff81901dce>] find_autofs_mount.isra.4+0x8e/0x200 fs/autofs4/dev-ioctl.c:213
 [<ffffffff81902c03>] autofs_dev_ioctl_open_mountpoint fs/autofs4/dev-ioctl.c:258 [inline]
 [<ffffffff81902c03>] autofs_dev_ioctl_openmount+0x153/0x2d0 fs/autofs4/dev-ioctl.c:303
 [<ffffffff81901b4b>] _autofs_dev_ioctl+0x4fb/0x690 fs/autofs4/dev-ioctl.c:699
 [<ffffffff81901cfb>] autofs_dev_ioctl+0x1b/0x30 fs/autofs4/dev-ioctl.c:714
 [<ffffffff815b051c>] vfs_ioctl fs/ioctl.c:43 [inline]
 [<ffffffff815b051c>] file_ioctl fs/ioctl.c:493 [inline]
 [<ffffffff815b051c>] do_vfs_ioctl+0x1ac/0x11a0 fs/ioctl.c:677
 [<ffffffff815b159f>] SYSC_ioctl fs/ioctl.c:694 [inline]
 [<ffffffff815b159f>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f3313>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Allocated by task 17662:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
 save_stack+0x43/0xd0 mm/kasan/kasan.c:505
 set_track mm/kasan/kasan.c:517 [inline]
 kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:609
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:547
 slab_post_alloc_hook mm/slab.h:417 [inline]
 slab_alloc_node mm/slub.c:2715 [inline]
 slab_alloc mm/slub.c:2723 [inline]
 __kmalloc_track_caller+0xdc/0x2b0 mm/slub.c:4232
 memdup_user+0x2c/0xb0 mm/util.c:161
 copy_dev_ioctl fs/autofs4/dev-ioctl.c:110 [inline]
 _autofs_dev_ioctl+0x13a/0x690 fs/autofs4/dev-ioctl.c:645
 autofs_dev_ioctl+0x1b/0x30 fs/autofs4/dev-ioctl.c:714
 vfs_ioctl fs/ioctl.c:43 [inline]
 file_ioctl fs/ioctl.c:493 [inline]
 do_vfs_ioctl+0x1ac/0x11a0 fs/ioctl.c:677
 SYSC_ioctl fs/ioctl.c:694 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
 do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Freed by task 22:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
 save_stack+0x43/0xd0 mm/kasan/kasan.c:505
 set_track mm/kasan/kasan.c:517 [inline]
 kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:582
 slab_free_hook mm/slub.c:1355 [inline]
 slab_free_freelist_hook mm/slub.c:1377 [inline]
 slab_free mm/slub.c:2958 [inline]
 kfree+0xfb/0x310 mm/slub.c:3878
 selinux_cred_free+0x48/0x70 security/selinux/hooks.c:3732
 security_cred_free+0x4e/0x90 security/security.c:909
 put_cred_rcu+0x62/0x270 kernel/cred.c:116
 __rcu_reclaim kernel/rcu/rcu.h:118 [inline]
 rcu_do_batch kernel/rcu/tree.c:2789 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:3053 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:3020 [inline]
 rcu_process_callbacks+0x8ae/0x12b0 kernel/rcu/tree.c:3037
 __do_softirq+0x20b/0x937 kernel/softirq.c:284

The buggy address belongs to the object at ffff8801cbb48210
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes to the right of
 32-byte region [ffff8801cbb48210, ffff8801cbb48230)
The buggy address belongs to the page:
page:ffffea00072ed200 count:1 mapcount:0 mapping:          (null) index:0x0
flags: 0x8000000000000080(slab)
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801cbb48100: fb fb fc fc fb fb fb fb fc fc fb fb fb fb fc fc
 ffff8801cbb48180: fb fb fb fb fc fc fb fb fb fb fc fc fb fb fb fb
>ffff8801cbb48200: fc fc 00 00 00 00 fc fc fb fb fb fb fc fc fb fb
                                     ^
 ffff8801cbb48280: fb fb fc fc fb fb fb fb fc fc fb fb fb fb fc fc
 ffff8801cbb48300: fb fb fb fb fc fc fb fb fb fb fc fc fb fb fb fb
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