================================================================== BUG: KASAN: slab-out-of-bounds in strlen+0x91/0xa0 lib/string.c:481 Read of size 1 at addr ffff8801b5f9a020 by task syz-executor267/3797 CPU: 1 PID: 3797 Comm: syz-executor267 Not tainted 4.9.105-gd7e64f8 #40 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801b5d1f978 ffffffff81eb41a9 ffffea0006d7e680 ffff8801b5f9a020 0000000000000000 ffff8801b5f9a020 ffff8801b5f9a018 ffff8801b5d1f9b0 ffffffff81567e49 ffff8801b5f9a020 0000000000000001 0000000000000000 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] print_address_description+0x6c/0x234 mm/kasan/report.c:256 [] kasan_report_error mm/kasan/report.c:355 [inline] [] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412 [] __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430 [] strlen+0x91/0xa0 lib/string.c:481 [] getname_kernel+0x24/0x340 fs/namei.c:215 [] kern_path_mountpoint+0x24/0x70 fs/namei.c:2754 [] find_autofs_mount.isra.4+0x8e/0x200 fs/autofs4/dev-ioctl.c:213 [] autofs_dev_ioctl_open_mountpoint fs/autofs4/dev-ioctl.c:258 [inline] [] autofs_dev_ioctl_openmount+0x153/0x2d0 fs/autofs4/dev-ioctl.c:303 [] _autofs_dev_ioctl+0x4fb/0x690 fs/autofs4/dev-ioctl.c:699 [] 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 Allocated by task 3797: 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 0: (stack is not available) The buggy address belongs to the object at ffff8801b5f9a000 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes to the right of 32-byte region [ffff8801b5f9a000, ffff8801b5f9a020) The buggy address belongs to the page: page:ffffea0006d7e680 count:1 mapcount:0 mapping: (null) index:0x0 flags: 0x8000000000000080(slab) page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801b5f99f00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8801b5f99f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8801b5f9a000: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8801b5f9a080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801b5f9a100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================