================================================================== BUG: KASAN: use-after-free in __read_once_size include/linux/compiler.h:188 [inline] BUG: KASAN: use-after-free in list_empty include/linux/list.h:203 [inline] BUG: KASAN: use-after-free in shrink_slab_memcg mm/vmscan.c:595 [inline] BUG: KASAN: use-after-free in shrink_slab+0xa04/0xa60 mm/vmscan.c:671 Read of size 8 at addr ffff880199dc6ad8 by task syz-executor6/11230 CPU: 0 PID: 11230 Comm: syz-executor6 Not tainted 4.18.0-rc4-next-20180713+ #7 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 __read_once_size include/linux/compiler.h:188 [inline] list_empty include/linux/list.h:203 [inline] shrink_slab_memcg mm/vmscan.c:595 [inline] shrink_slab+0xa04/0xa60 mm/vmscan.c:671 shrink_node+0x429/0x16a0 mm/vmscan.c:2735 shrink_zones mm/vmscan.c:2964 [inline] do_try_to_free_pages+0x3e7/0x1290 mm/vmscan.c:3026 try_to_free_mem_cgroup_pages+0x49d/0xc90 mm/vmscan.c:3324 memory_high_write+0x283/0x310 mm/memcontrol.c:5611 cgroup_file_write+0x31f/0x840 kernel/cgroup/cgroup.c:3502 kernfs_fop_write+0x2ba/0x480 fs/kernfs/file.c:316 __vfs_write+0x117/0x9d0 fs/read_write.c:485 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455ab9 Code: 1d ba fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0eb159dc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f0eb159e6d4 RCX: 0000000000455ab9 RDX: 0000000000000001 RSI: 0000000020000000 RDI: 0000000000000017 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004c2c77 R14: 00000000004d4c80 R15: 0000000000000000 Allocated by task 10399: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kmem_cache_alloc_trace+0x152/0x780 mm/slab.c:3620 kmalloc include/linux/slab.h:513 [inline] kzalloc include/linux/slab.h:707 [inline] kernfs_iop_get_link+0x6d/0x660 fs/kernfs/symlink.c:124 get_link fs/namei.c:1084 [inline] trailing_symlink+0x77e/0x980 fs/namei.c:2268 path_openat+0xd01/0x5430 fs/namei.c:3570 do_filp_open+0x255/0x380 fs/namei.c:3605 do_sys_open+0x584/0x720 fs/open.c:1077 __do_sys_open fs/open.c:1095 [inline] __se_sys_open fs/open.c:1090 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1090 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 10399: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xd9/0x260 mm/slab.c:3813 kfree_link+0x15/0x20 fs/libfs.c:1120 do_delayed_call include/linux/delayed_call.h:28 [inline] put_link fs/namei.c:883 [inline] step_into fs/namei.c:1772 [inline] do_last fs/namei.c:3405 [inline] path_openat+0x1e8c/0x5430 fs/namei.c:3568 do_filp_open+0x255/0x380 fs/namei.c:3605 do_sys_open+0x584/0x720 fs/open.c:1077 __do_sys_open fs/open.c:1095 [inline] __se_sys_open fs/open.c:1090 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1090 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff880199dc6380 which belongs to the cache kmalloc-4096 of size 4096 The buggy address is located 1880 bytes inside of 4096-byte region [ffff880199dc6380, ffff880199dc7380) The buggy address belongs to the page: page:ffffea0006677180 count:1 mapcount:0 mapping:ffff8801da800dc0 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000008100(slab|head) raw: 02fffc0000008100 ffffea0006617f88 ffffea00063a8d88 ffff8801da800dc0 raw: 0000000000000000 ffff880199dc6380 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff880199dc6980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff880199dc6a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff880199dc6a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff880199dc6b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff880199dc6b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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