================================================================== BUG: KASAN: slab-out-of-bounds in css_task_iter_advance+0x49b/0x540 kernel/cgroup/cgroup.c:4507 Read of size 4 at addr ffff888091391d9c by task syz-executor.3/25514 CPU: 0 PID: 25514 Comm: syz-executor.3 Not tainted 5.2.0-rc3-next-20190607 #11 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+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0xd4/0x306 mm/kasan/report.c:351 __kasan_report.cold+0x1b/0x36 mm/kasan/report.c:482 kasan_report+0x12/0x20 mm/kasan/common.c:614 __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:131 css_task_iter_advance+0x49b/0x540 kernel/cgroup/cgroup.c:4507 css_task_iter_start+0x18b/0x230 kernel/cgroup/cgroup.c:4543 update_tasks_cpumask+0x8c/0x110 kernel/cgroup/cpuset.c:1017 update_cpumasks_hier+0x68f/0x1620 kernel/cgroup/cpuset.c:1397 update_cpumask kernel/cgroup/cpuset.c:1523 [inline] cpuset_write_resmask+0x132b/0x2030 kernel/cgroup/cpuset.c:2350 cgroup_file_write+0x241/0x790 kernel/cgroup/cgroup.c:3711 kernfs_fop_write+0x2b8/0x480 fs/kernfs/file.c:316 __vfs_write+0x8a/0x110 fs/read_write.c:494 __kernel_write+0x110/0x3b0 fs/read_write.c:515 write_pipe_buf+0x15d/0x1f0 fs/splice.c:794 splice_from_pipe_feed fs/splice.c:500 [inline] __splice_from_pipe+0x38c/0x7d0 fs/splice.c:624 splice_from_pipe+0x108/0x170 fs/splice.c:659 default_file_splice_write+0x3c/0x90 fs/splice.c:806 do_splice_from fs/splice.c:848 [inline] direct_splice_actor+0x123/0x190 fs/splice.c:1020 splice_direct_to_actor+0x366/0x970 fs/splice.c:975 do_splice_direct+0x1da/0x2a0 fs/splice.c:1063 do_sendfile+0x597/0xd00 fs/read_write.c:1464 __do_sys_sendfile64 fs/read_write.c:1525 [inline] __se_sys_sendfile64 fs/read_write.c:1511 [inline] __x64_sys_sendfile64+0x1dd/0x220 fs/read_write.c:1511 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459279 Code: fd b7 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f9e912afc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000459279 RDX: 0000000000000000 RSI: 0000000000000007 RDI: 0000000000000006 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000004 R11: 0000000000000246 R12: 00007f9e912b06d4 R13: 00000000004c6835 R14: 00000000004db7a8 R15: 00000000ffffffff Allocated by task 22132: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc mm/kasan/common.c:489 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:503 kmem_cache_alloc_trace+0x151/0x750 mm/slab.c:3549 kmalloc include/linux/slab.h:547 [inline] kzalloc include/linux/slab.h:742 [inline] uevent_show+0x165/0x370 drivers/base/core.c:1222 dev_attr_show+0x50/0xa0 drivers/base/core.c:931 sysfs_kf_seq_show+0x1fc/0x410 fs/sysfs/file.c:60 kernfs_seq_show+0x14f/0x1b0 fs/kernfs/file.c:168 seq_read+0x4ca/0x1110 fs/seq_file.c:229 kernfs_fop_read+0xed/0x560 fs/kernfs/file.c:252 __vfs_read+0x8a/0x110 fs/read_write.c:425 vfs_read+0x1f0/0x440 fs/read_write.c:461 ksys_read+0x14f/0x290 fs/read_write.c:587 __do_sys_read fs/read_write.c:597 [inline] __se_sys_read fs/read_write.c:595 [inline] __x64_sys_read+0x73/0xb0 fs/read_write.c:595 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 22132: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:451 kasan_slab_free+0xe/0x10 mm/kasan/common.c:459 __cache_free mm/slab.c:3426 [inline] kfree+0x106/0x2a0 mm/slab.c:3753 uevent_show+0x2ca/0x370 drivers/base/core.c:1235 dev_attr_show+0x50/0xa0 drivers/base/core.c:931 sysfs_kf_seq_show+0x1fc/0x410 fs/sysfs/file.c:60 kernfs_seq_show+0x14f/0x1b0 fs/kernfs/file.c:168 seq_read+0x4ca/0x1110 fs/seq_file.c:229 kernfs_fop_read+0xed/0x560 fs/kernfs/file.c:252 __vfs_read+0x8a/0x110 fs/read_write.c:425 vfs_read+0x1f0/0x440 fs/read_write.c:461 ksys_read+0x14f/0x290 fs/read_write.c:587 __do_sys_read fs/read_write.c:597 [inline] __se_sys_read fs/read_write.c:595 [inline] __x64_sys_read+0x73/0xb0 fs/read_write.c:595 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888091390740 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1628 bytes to the right of 4096-byte region [ffff888091390740, ffff888091391740) The buggy address belongs to the page: page:ffffea000244e400 refcount:1 mapcount:0 mapping:ffff8880aa400dc0 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea00016f1508 ffffea0002a47188 ffff8880aa400dc0 raw: 0000000000000000 ffff888091390740 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888091391c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888091391d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888091391d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888091391e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888091391e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================