================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x3c41/0x3cf0 kernel/locking/lockdep.c:3305 Read of size 8 at addr ffff8801d66fb1a0 by task syz-executor4/32309 CPU: 0 PID: 32309 Comm: syz-executor4 Not tainted 4.15.0-rc6-next-20180102+ #86 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+0x137/0x198 lib/dump_stack.c:53 print_address_description+0x73/0x250 mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:355 [inline] kasan_report+0x23b/0x360 mm/kasan/report.c:413 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:434 __lock_acquire+0x3c41/0x3cf0 kernel/locking/lockdep.c:3305 lock_acquire+0x16b/0x420 kernel/locking/lockdep.c:3914 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:310 [inline] shmem_fault+0x503/0x710 mm/shmem.c:1984 __do_fault+0x8a/0x1d0 mm/memory.c:3206 do_read_fault mm/memory.c:3616 [inline] do_fault mm/memory.c:3716 [inline] handle_pte_fault mm/memory.c:3947 [inline] __handle_mm_fault+0x1c96/0x3210 mm/memory.c:4071 handle_mm_fault+0x305/0x840 mm/memory.c:4108 __do_page_fault+0x59e/0xca0 arch/x86/mm/fault.c:1429 do_page_fault+0x78/0x490 arch/x86/mm/fault.c:1504 page_fault+0x4c/0x60 arch/x86/entry/entry_64.S:1243 RIP: 0033:0x452ad5 RSP: 002b:000000002098d000 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 000000000071bea0 RCX: 0000000000452ac9 RDX: 0000000020651000 RSI: 000000002098d000 RDI: 00000000000001fe RBP: 0000000000000048 R08: 000000002095c000 R09: 0000000000000000 R10: 0000000020c6f000 R11: 0000000000000212 R12: 00000000006ee760 R13: 00000000ffffffff R14: 00007f2efe33e6d4 R15: 0000000000000000 Allocated by task 32297: 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 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3541 shmem_alloc_inode+0x1b/0x40 mm/shmem.c:3846 alloc_inode+0x65/0x180 fs/inode.c:209 new_inode_pseudo+0x17/0xe0 fs/inode.c:890 new_inode+0x1c/0x40 fs/inode.c:919 shmem_get_inode+0x71/0x760 mm/shmem.c:2160 __shmem_file_setup.part.44+0x33f/0x420 mm/shmem.c:4221 __shmem_file_setup mm/shmem.c:4303 [inline] shmem_kernel_file_setup mm/shmem.c:4259 [inline] shmem_zero_setup+0xd9/0x3e0 mm/shmem.c:4303 mmap_region+0xdb8/0x1010 mm/mmap.c:1732 do_mmap+0x623/0xda0 mm/mmap.c:1494 do_mmap_pgoff include/linux/mm.h:2224 [inline] vm_mmap_pgoff+0x19c/0x1f0 mm/util.c:333 SYSC_mmap_pgoff mm/mmap.c:1544 [inline] SyS_mmap_pgoff+0x1fc/0x580 mm/mmap.c:1502 SYSC_mmap arch/x86/kernel/sys_x86_64.c:100 [inline] SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:91 entry_SYSCALL_64_fastpath+0x23/0x9a Freed by task 3476: 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:3485 [inline] kmem_cache_free+0x83/0x2a0 mm/slab.c:3743 shmem_destroy_callback+0x5a/0xa0 mm/shmem.c:3857 __rcu_reclaim kernel/rcu/rcu.h:172 [inline] rcu_do_batch kernel/rcu/tree.c:2675 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2934 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2901 [inline] rcu_process_callbacks+0x5cf/0x1200 kernel/rcu/tree.c:2918 __do_softirq+0x23f/0x99f kernel/softirq.c:285 The buggy address belongs to the object at ffff8801d66fb000 which belongs to the cache shmem_inode_cache of size 1200 The buggy address is located 416 bytes inside of 1200-byte region [ffff8801d66fb000, ffff8801d66fb4b0) The buggy address belongs to the page: page:ffffea000759bec0 count:1 mapcount:0 mapping:ffff8801d66fb000 index:0xffff8801d66fbffd flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffff8801d66fb000 ffff8801d66fbffd 0000000100000003 raw: ffffea0007542a60 ffffea0007536720 ffff8801da2a44c0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d66fb080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d66fb100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801d66fb180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801d66fb200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d66fb280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================