cgroup: fork rejected by pids controller in /syz1 ================================================================== BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] BUG: KASAN: use-after-free in refcount_read include/linux/refcount.h:43 [inline] BUG: KASAN: use-after-free in skb_unref include/linux/skbuff.h:967 [inline] BUG: KASAN: use-after-free in kfree_skb+0x38/0x390 net/core/skbuff.c:659 Read of size 4 at addr ffff888096c80124 by task syz-executor.5/9731 CPU: 1 PID: 9731 Comm: syz-executor.5 Not tainted 4.19.83 #0 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+0x7c/0x20d mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report mm/kasan/report.c:412 [inline] kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:396 check_memory_region_inline mm/kasan/kasan.c:260 [inline] check_memory_region+0x123/0x190 mm/kasan/kasan.c:267 kasan_check_read+0x11/0x20 mm/kasan/kasan.c:272 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] refcount_read include/linux/refcount.h:43 [inline] skb_unref include/linux/skbuff.h:967 [inline] kfree_skb+0x38/0x390 net/core/skbuff.c:659 bcsp_close+0xc7/0x130 drivers/bluetooth/hci_bcsp.c:763 hci_uart_tty_close+0x1ea/0x250 drivers/bluetooth/hci_ldisc.c:555 tty_ldisc_close.isra.0+0xaf/0xe0 drivers/tty/tty_ldisc.c:486 tty_ldisc_kill+0x4b/0xc0 drivers/tty/tty_ldisc.c:632 tty_ldisc_release+0xc6/0x280 drivers/tty/tty_ldisc.c:799 tty_release_struct+0x1b/0x50 drivers/tty/tty_io.c:1611 tty_release+0xbcb/0xe90 drivers/tty/tty_io.c:1784 __fput+0x2dd/0x8b0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x145/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x53d/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x413db1 Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007fff414024e0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 000000000000000a RCX: 0000000000413db1 RDX: 0000000000000000 RSI: 0000000000001bb3 RDI: 0000000000000009 RBP: 0000000000000001 R08: 000000001543dbb3 R09: 000000001543dbb7 R10: 00007fff414025c0 R11: 0000000000000293 R12: 000000000075c9a0 R13: 000000000075c9a0 R14: 00000000007605b8 R15: 000000000075c07c Allocated by task 224: save_stack+0x45/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc mm/kasan/kasan.c:553 [inline] kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:531 kasan_slab_alloc+0xf/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc_node+0x144/0x710 mm/slab.c:3649 __alloc_skb+0xd5/0x5f0 net/core/skbuff.c:193 alloc_skb include/linux/skbuff.h:995 [inline] bt_skb_alloc include/net/bluetooth/bluetooth.h:339 [inline] bcsp_recv+0x8c7/0x13a0 drivers/bluetooth/hci_bcsp.c:685 hci_uart_tty_receive+0x225/0x530 drivers/bluetooth/hci_ldisc.c:620 tty_ldisc_receive_buf+0x15f/0x1c0 drivers/tty/tty_buffer.c:460 tty_port_default_receive_buf+0x7d/0xb0 drivers/tty/tty_port.c:38 receive_buf drivers/tty/tty_buffer.c:476 [inline] flush_to_ldisc+0x222/0x390 drivers/tty/tty_buffer.c:528 process_one_work+0x989/0x1750 kernel/workqueue.c:2153 worker_thread+0x98/0xe40 kernel/workqueue.c:2296 netlink: 'syz-executor.2': attribute type 10 has an invalid length. kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Freed by task 224: netlink: 'syz-executor.2': attribute type 3 has an invalid length. save_stack+0x45/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3503 [inline] kmem_cache_free+0x86/0x260 mm/slab.c:3765 kobject: 'kvm' (000000006eb26d03): fill_kobj_path: path = '/devices/virtual/misc/kvm' kfree_skbmem net/core/skbuff.c:586 [inline] kfree_skbmem+0xcb/0x150 net/core/skbuff.c:580 __kfree_skb net/core/skbuff.c:646 [inline] kfree_skb net/core/skbuff.c:663 [inline] kfree_skb+0xf0/0x390 net/core/skbuff.c:657 bcsp_recv+0x2d8/0x13a0 drivers/bluetooth/hci_bcsp.c:623 hci_uart_tty_receive+0x225/0x530 drivers/bluetooth/hci_ldisc.c:620 tty_ldisc_receive_buf+0x15f/0x1c0 drivers/tty/tty_buffer.c:460 tty_port_default_receive_buf+0x7d/0xb0 drivers/tty/tty_port.c:38 receive_buf drivers/tty/tty_buffer.c:476 [inline] flush_to_ldisc+0x222/0x390 drivers/tty/tty_buffer.c:528 process_one_work+0x989/0x1750 kernel/workqueue.c:2153 worker_thread+0x98/0xe40 kernel/workqueue.c:2296 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 kobject: 'loop2' (00000000bad02a8e): kobject_uevent_env The buggy address belongs to the object at ffff888096c80040 which belongs to the cache skbuff_head_cache of size 232 netlink: 24 bytes leftover after parsing attributes in process `syz-executor.2'. The buggy address is located 228 bytes inside of 232-byte region [ffff888096c80040, ffff888096c80128) The buggy address belongs to the page: page:ffffea00025b2000 count:1 mapcount:0 mapping:ffff88821bab29c0 index:0x0 flags: 0x1fffc0000000100(slab) raw: 01fffc0000000100 ffffea00025b7288 ffffea00021cf7c8 ffff88821bab29c0 raw: 0000000000000000 ffff888096c80040 000000010000000c 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888096c80000: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff888096c80080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888096c80100: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc ^ ffff888096c80180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888096c80200: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ==================================================================