================================================================== BUG: KASAN: slab-out-of-bounds in strlen+0x91/0xa0 lib/string.c:481 Read of size 1 at addr ffff8801b5881260 by task syz-executor1/31656 CPU: 0 PID: 31656 Comm: syz-executor1 Not tainted 4.9.96-g71fce1e #10 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801cb67f978 ffffffff81eb0b69 ffffea0006d62040 ffff8801b5881260 0000000000000000 ffff8801b5881260 ffff8801b5881258 ffff8801cb67f9b0 ffffffff8156540b ffff8801b5881260 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 31656: 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 29999: 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 single_release+0x88/0xb0 fs/seq_file.c:609 close_pdeo+0x110/0x230 fs/proc/inode.c:153 proc_reg_release+0x127/0x160 fs/proc/inode.c:359 __fput+0x263/0x700 fs/file_table.c:208 ____fput+0x15/0x20 fs/file_table.c:244 task_work_run+0x10c/0x180 kernel/task_work.c:116 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0xfc/0x120 arch/x86/entry/common.c:161 prepare_exit_to_usermode arch/x86/entry/common.c:191 [inline] syscall_return_slowpath arch/x86/entry/common.c:260 [inline] do_syscall_64+0x364/0x490 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_swapgs+0x5d/0xdb The buggy address belongs to the object at ffff8801b5881240 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes to the right of 32-byte region [ffff8801b5881240, ffff8801b5881260) The buggy address belongs to the page: page:ffffea0006d62040 count:1 mapcount:0 mapping: (null) index:0x0 flags: 0x8000000000000080(slab) page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801b5881100: fb fb fc fc fb fb fb fb fc fc fb fb fb fb fc fc ffff8801b5881180: 00 00 00 00 fc fc fb fb fb fb fc fc 00 00 00 00 >ffff8801b5881200: fc fc fb fb fb fb fc fc 00 00 00 00 fc fc fb fb ^ ffff8801b5881280: fb fb fc fc fb fb fb fb fc fc fb fb fb fb fc fc ffff8801b5881300: 00 00 00 00 fc fc fb fb fb fb fc fc fb fb fb fb ==================================================================