audit: type=1400 audit(1521630404.387:120): avc: denied { create } for pid=17825 comm="syz-executor3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_iscsi_socket permissive=1 ================================================================== BUG: KASAN: use-after-free in __read_once_size include/linux/compiler.h:243 [inline] BUG: KASAN: use-after-free in list_empty include/linux/list.h:189 [inline] BUG: KASAN: use-after-free in sg_remove_request+0x103/0x120 drivers/scsi/sg.c:2110 Read of size 8 at addr ffff8801c15accc0 by task syz-executor5/17840 CPU: 0 PID: 17840 Comm: syz-executor5 Not tainted 4.9.88-g71df7bb #8 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801bcb0f930 ffffffff81d95f19 ffffea0007056b00 ffff8801c15accc0 0000000000000000 ffff8801c15accc0 ffff8801cd55a338 ffff8801bcb0f968 ffffffff8153e793 ffff8801c15accc0 0000000000000008 0000000000000000 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] print_address_description+0x73/0x280 mm/kasan/report.c:256 [] kasan_report_error mm/kasan/report.c:355 [inline] [] kasan_report+0x255/0x380 mm/kasan/report.c:412 [] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 [] __read_once_size include/linux/compiler.h:243 [inline] [] list_empty include/linux/list.h:189 [inline] [] sg_remove_request+0x103/0x120 drivers/scsi/sg.c:2110 [] sg_finish_rem_req+0x295/0x340 drivers/scsi/sg.c:1827 [] sg_read+0xa16/0x1440 drivers/scsi/sg.c:526 [] do_loop_readv_writev.part.17+0xc8/0x2b0 fs/read_write.c:715 [] do_loop_readv_writev fs/read_write.c:1097 [inline] [] compat_do_readv_writev+0x5ff/0x740 fs/read_write.c:1091 [] compat_readv+0xe3/0x150 fs/read_write.c:1120 [] do_compat_readv+0xf4/0x1d0 fs/read_write.c:1140 [] C_SYSC_readv fs/read_write.c:1152 [inline] [] compat_SyS_readv+0x26/0x30 fs/read_write.c:1148 [] do_syscall_32_irqs_on arch/x86/entry/common.c:325 [inline] [] do_fast_syscall_32+0x2f5/0x870 arch/x86/entry/common.c:387 [] entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137 Allocated by task 14434: 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+0xad/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] kmem_cache_alloc+0xba/0x290 mm/slub.c:2728 fasync_alloc fs/fcntl.c:608 [inline] fasync_add_entry fs/fcntl.c:666 [inline] fasync_helper+0x37/0xb0 fs/fcntl.c:695 random_fasync+0x2a/0x40 drivers/char/random.c:1860 ioctl_fioasync fs/ioctl.c:534 [inline] do_vfs_ioctl+0x2d8/0x1140 fs/ioctl.c:639 C_SYSC_ioctl fs/compat_ioctl.c:1624 [inline] compat_SyS_ioctl+0x4da/0x2050 fs/compat_ioctl.c:1549 do_syscall_32_irqs_on arch/x86/entry/common.c:325 [inline] do_fast_syscall_32+0x2f5/0x870 arch/x86/entry/common.c:387 entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137 Freed by task 17: 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] kmem_cache_free+0xc7/0x300 mm/slub.c:2980 fasync_free_rcu+0x1d/0x20 fs/fcntl.c:567 __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+0x898/0x1300 kernel/rcu/tree.c:3037 __do_softirq+0x206/0x951 kernel/softirq.c:284 The buggy address belongs to the object at ffff8801c15acc80 which belongs to the cache fasync_cache of size 96 The buggy address is located 64 bytes inside of 96-byte region [ffff8801c15acc80, ffff8801c15acce0) The buggy address belongs to the page: page:ffffea0007056b00 count:1 mapcount:0 mapping: (null) index:0x0 flags: 0x8000000000000080(slab) page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c15acb80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc ffff8801c15acc00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff8801c15acc80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff8801c15acd00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8801c15acd80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ==================================================================