================================================================== BUG: KASAN: slab-out-of-bounds in thread_group_leader include/linux/sched/signal.h:631 [inline] BUG: KASAN: slab-out-of-bounds in css_task_iter_advance+0x4a5/0x540 kernel/cgroup/cgroup.c:4499 Read of size 4 at addr ffff88808c7438f4 by task syz-executor.5/981 CPU: 0 PID: 981 Comm: syz-executor.5 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 thread_group_leader include/linux/sched/signal.h:631 [inline] css_task_iter_advance+0x4a5/0x540 kernel/cgroup/cgroup.c:4499 css_task_iter_start+0x18b/0x230 kernel/cgroup/cgroup.c:4543 __cgroup_procs_start.isra.0+0x32f/0x400 kernel/cgroup/cgroup.c:4638 cgroup_procs_start kernel/cgroup/cgroup.c:4660 [inline] cgroup_procs_start+0x1e7/0x260 kernel/cgroup/cgroup.c:4647 cgroup_seqfile_start+0xa4/0xd0 kernel/cgroup/cgroup.c:3752 kernfs_seq_start+0xdc/0x190 fs/kernfs/file.c:118 seq_read+0x2a7/0x1110 fs/seq_file.c:224 kernfs_fop_read+0xed/0x560 fs/kernfs/file.c:252 do_loop_readv_writev fs/read_write.c:714 [inline] do_loop_readv_writev fs/read_write.c:701 [inline] do_iter_read+0x4a4/0x660 fs/read_write.c:935 vfs_readv+0xf0/0x160 fs/read_write.c:997 kernel_readv fs/splice.c:359 [inline] default_file_splice_read+0x475/0x890 fs/splice.c:414 do_splice_to+0x127/0x180 fs/splice.c:877 splice_direct_to_actor+0x2d2/0x970 fs/splice.c:954 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:00007fd090dbbc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000459279 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 00007fd090dbc6d4 R13: 00000000004c6835 R14: 00000000004db7a8 R15: 00000000ffffffff Allocated by task 9676: 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 __do_kmalloc mm/slab.c:3654 [inline] __kmalloc+0x15c/0x740 mm/slab.c:3663 kmalloc include/linux/slab.h:552 [inline] tomoyo_realpath_from_path+0xcd/0x7a0 security/tomoyo/realpath.c:277 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path2_perm+0x344/0x670 security/tomoyo/file.c:923 tomoyo_path_rename+0xee/0x150 security/tomoyo/tomoyo.c:285 security_path_rename+0x20c/0x300 security/security.c:1036 do_renameat2+0x7b8/0xc40 fs/namei.c:4621 __do_sys_rename fs/namei.c:4671 [inline] __se_sys_rename fs/namei.c:4669 [inline] __x64_sys_rename+0x61/0x80 fs/namei.c:4669 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 9676: 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 tomoyo_realpath_from_path+0x1de/0x7a0 security/tomoyo/realpath.c:319 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path2_perm+0x344/0x670 security/tomoyo/file.c:923 tomoyo_path_rename+0xee/0x150 security/tomoyo/tomoyo.c:285 security_path_rename+0x20c/0x300 security/security.c:1036 do_renameat2+0x7b8/0xc40 fs/namei.c:4621 __do_sys_rename fs/namei.c:4671 [inline] __se_sys_rename fs/namei.c:4669 [inline] __x64_sys_rename+0x61/0x80 fs/namei.c:4669 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 ffff88808c742280 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1652 bytes to the right of 4096-byte region [ffff88808c742280, ffff88808c743280) The buggy address belongs to the page: page:ffffea000231d080 refcount:1 mapcount:0 mapping:ffff8880aa400dc0 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0002864808 ffffea0002502d88 ffff8880aa400dc0 raw: 0000000000000000 ffff88808c742280 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808c743780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88808c743800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88808c743880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88808c743900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88808c743980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================