================================================================== 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 ffff8801c04a2e40 by task syz-executor1/15648 CPU: 1 PID: 15648 Comm: syz-executor1 Not tainted 4.9.85-g4c4262a #55 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801c2b9fa50 ffffffff81d95739 ffffea0007012880 ffff8801c04a2e40 0000000000000000 ffff8801c04a2e40 ffff8801b8ec8238 ffff8801c2b9fa88 ffffffff8153e0d3 ffff8801c04a2e40 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:252 [] kasan_report_error mm/kasan/report.c:351 [inline] [] kasan_report+0x275/0x360 mm/kasan/report.c:408 [] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429 [] __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 [] __vfs_read+0x103/0x670 fs/read_write.c:449 [] vfs_read+0x11e/0x380 fs/read_write.c:472 [] SYSC_read fs/read_write.c:588 [inline] [] SyS_read+0xd9/0x1b0 fs/read_write.c:581 [] 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 12926: 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 3893: 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 ffff8801c04a2e00 which belongs to the cache fasync_cache of size 96 The buggy address is located 64 bytes inside of 96-byte region [ffff8801c04a2e00, ffff8801c04a2e60) The buggy address belongs to the page: page:ffffea0007012880 count:1 mapcount:0 mapping: (null) index:0xffff8801c04a2b00 flags: 0x8000000000000080(slab) page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c04a2d00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc ffff8801c04a2d80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff8801c04a2e00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff8801c04a2e80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8801c04a2f00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ==================================================================