================================================================== BUG: KASAN: slab-out-of-bounds in css_task_iter_advance+0x49b/0x540 kernel/cgroup/cgroup.c:4507 Read of size 4 at addr ffff8880955b7d5c by task syz-executor.0/10677 CPU: 1 PID: 10677 Comm: syz-executor.0 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 mem_cgroup_scan_tasks+0xaf/0x180 mm/memcontrol.c:1167 select_bad_process mm/oom_kill.c:374 [inline] out_of_memory mm/oom_kill.c:1088 [inline] out_of_memory+0x6b2/0x1280 mm/oom_kill.c:1035 mem_cgroup_out_of_memory+0x1ca/0x230 mm/memcontrol.c:1573 mem_cgroup_oom mm/memcontrol.c:1905 [inline] try_charge+0xfbe/0x1480 mm/memcontrol.c:2468 mem_cgroup_charge_skmem+0x12f/0x280 mm/memcontrol.c:6452 __sk_mem_raise_allocated+0x555/0x1380 net/core/sock.c:2477 __sk_mem_schedule+0x6d/0xe0 net/core/sock.c:2562 sk_wmem_schedule include/net/sock.h:1413 [inline] tcp_sendmsg_locked+0x1993/0x3920 net/ipv4/tcp.c:1306 tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1415 inet_sendmsg+0x141/0x5d0 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:665 __sys_sendto+0x262/0x380 net/socket.c:1958 __do_sys_sendto net/socket.c:1970 [inline] __se_sys_sendto net/socket.c:1966 [inline] __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1966 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:00007f143e818c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000459279 RDX: 00000000ffffff45 RSI: 0000000020000000 RDI: 0000000000000006 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000000c0 R11: 0000000000000246 R12: 00007f143e8196d4 R13: 00000000004c700b R14: 00000000004dc1c8 R15: 00000000ffffffff Allocated by task 29510: 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_slab_alloc+0xf/0x20 mm/kasan/common.c:497 slab_post_alloc_hook mm/slab.h:444 [inline] slab_alloc mm/slab.c:3320 [inline] kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3482 getname_flags fs/namei.c:138 [inline] getname_flags+0xd6/0x5b0 fs/namei.c:128 getname fs/namei.c:209 [inline] user_path_create fs/namei.c:3692 [inline] do_symlinkat+0xe1/0x290 fs/namei.c:4145 __do_sys_symlink fs/namei.c:4171 [inline] __se_sys_symlink fs/namei.c:4169 [inline] __x64_sys_symlink+0x59/0x80 fs/namei.c:4169 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 29510: 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] kmem_cache_free+0x86/0x320 mm/slab.c:3692 putname+0xef/0x130 fs/namei.c:259 filename_create+0x26f/0x4f0 fs/namei.c:3657 user_path_create fs/namei.c:3692 [inline] do_symlinkat+0xf3/0x290 fs/namei.c:4145 __do_sys_symlink fs/namei.c:4171 [inline] __se_sys_symlink fs/namei.c:4169 [inline] __x64_sys_symlink+0x59/0x80 fs/namei.c:4169 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 ffff8880955b6400 which belongs to the cache names_cache of size 4096 The buggy address is located 2396 bytes to the right of 4096-byte region [ffff8880955b6400, ffff8880955b7400) The buggy address belongs to the page: page:ffffea0002556d80 refcount:1 mapcount:0 mapping:ffff8880aa594c40 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea000263cb08 ffffea000255a288 ffff8880aa594c40 raw: 0000000000000000 ffff8880955b6400 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880955b7c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880955b7c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880955b7d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880955b7d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880955b7e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc 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