syzbot has found a reproducer for the following issue on: HEAD commit: 568035b01cfb Linux 6.0-rc1 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=156286a5080000 kernel config: https://syzkaller.appspot.com/x/.config?x=e706e91b2a433db dashboard link: https://syzkaller.appspot.com/bug?extid=f1a69784f6efe748c3bf compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13e5b2f3080000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12550915080000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+f1a69784f6efe748c3bf@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: use-after-free in __create_pipe include/linux/usb.h:1945 [inline] BUG: KASAN: use-after-free in send_packet+0xa2d/0xbc0 drivers/media/rc/imon.c:627 Read of size 4 at addr ffff8880256fb000 by task syz-executor314/4465 CPU: 2 PID: 4465 Comm: syz-executor314 Not tainted 6.0.0-rc1-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:317 [inline] print_report.cold+0x2ba/0x6e9 mm/kasan/report.c:433 kasan_report+0xb1/0x1e0 mm/kasan/report.c:495 __create_pipe include/linux/usb.h:1945 [inline] send_packet+0xa2d/0xbc0 drivers/media/rc/imon.c:627 vfd_write+0x2d9/0x550 drivers/media/rc/imon.c:991 vfs_write+0x2d7/0xdd0 fs/read_write.c:576 ksys_write+0x127/0x250 fs/read_write.c:631 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f7590342b49 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 15 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f75902cd308 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f75903c74d8 RCX: 00007f7590342b49 RDX: 0000000000000001 RSI: 0000000020001000 RDI: 0000000000000004 RBP: 00007f75903c74d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f75903c74dc R13: 00007f7590394328 R14: 0b8b0509005504e1 R15: 0000000000022000 </TASK> Allocated by task 3757: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:437 [inline] ____kasan_kmalloc mm/kasan/common.c:516 [inline] ____kasan_kmalloc mm/kasan/common.c:475 [inline] __kasan_kmalloc+0xa6/0xd0 mm/kasan/common.c:525 kasan_kmalloc include/linux/kasan.h:234 [inline] kmem_cache_alloc_trace+0x25a/0x460 mm/slab.c:3559 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:733 [inline] usb_alloc_dev+0x51/0xf00 drivers/usb/core/usb.c:582 hub_port_connect drivers/usb/core/hub.c:5255 [inline] hub_port_connect_change drivers/usb/core/hub.c:5497 [inline] port_event drivers/usb/core/hub.c:5653 [inline] hub_event+0x214a/0x4610 drivers/usb/core/hub.c:5735 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Freed by task 3737: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:367 [inline] ____kasan_slab_free+0x13d/0x1a0 mm/kasan/common.c:329 kasan_slab_free include/linux/kasan.h:200 [inline] __cache_free mm/slab.c:3418 [inline] kfree+0x173/0x390 mm/slab.c:3786 device_release+0x9f/0x240 drivers/base/core.c:2330 kobject_cleanup lib/kobject.c:673 [inline] kobject_release lib/kobject.c:704 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1be/0x4c0 lib/kobject.c:721 put_device+0x1b/0x30 drivers/base/core.c:3624 hub_port_connect drivers/usb/core/hub.c:5197 [inline] hub_port_connect_change drivers/usb/core/hub.c:5497 [inline] port_event drivers/usb/core/hub.c:5653 [inline] hub_event+0x1f86/0x4610 drivers/usb/core/hub.c:5735 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0x7e/0x90 mm/kasan/generic.c:348 kvfree_call_rcu+0x74/0x940 kernel/rcu/tree.c:3322 free_imon_context+0x15b/0x1f0 drivers/media/rc/imon.c:503 imon_disconnect+0x4b9/0x660 drivers/media/rc/imon.c:2543 usb_unbind_interface+0x1d8/0x8e0 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:520 [inline] device_remove+0x11f/0x170 drivers/base/dd.c:512 __device_release_driver drivers/base/dd.c:1209 [inline] device_release_driver_internal+0x4a1/0x700 drivers/base/dd.c:1235 bus_remove_device+0x2e3/0x590 drivers/base/bus.c:529 device_del+0x4f3/0xc80 drivers/base/core.c:3704 usb_disable_device+0x356/0x7a0 drivers/usb/core/message.c:1419 usb_disconnect.cold+0x259/0x6ed drivers/usb/core/hub.c:2235 hub_port_connect drivers/usb/core/hub.c:5197 [inline] hub_port_connect_change drivers/usb/core/hub.c:5497 [inline] port_event drivers/usb/core/hub.c:5653 [inline] hub_event+0x1f86/0x4610 drivers/usb/core/hub.c:5735 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Second to last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0x7e/0x90 mm/kasan/generic.c:348 call_rcu+0x99/0x790 kernel/rcu/tree.c:2793 netlink_release+0xeff/0x1db0 net/netlink/af_netlink.c:815 __sock_release+0xcd/0x280 net/socket.c:650 sock_close+0x18/0x20 net/socket.c:1365 __fput+0x277/0x9d0 fs/file_table.c:320 task_work_run+0xdd/0x1a0 kernel/task_work.c:177 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xad5/0x29b0 kernel/exit.c:795 do_group_exit+0xd2/0x2f0 kernel/exit.c:925 __do_sys_exit_group kernel/exit.c:936 [inline] __se_sys_exit_group kernel/exit.c:934 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:934 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff8880256fb000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 0 bytes inside of 2048-byte region [ffff8880256fb000, ffff8880256fb800) The buggy address belongs to the physical page: page:ffffea000095bec0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x256fb flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea000089bb88 ffffea0000727fc8 ffff888011840800 raw: 0000000000000000 ffff8880256fb000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x2420c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_COMP|__GFP_THISNODE), pid 3133, tgid 3133 (udevd), ts 116180599550, free_ts 116180286761 prep_new_page mm/page_alloc.c:2532 [inline] get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5515 __alloc_pages_node include/linux/gfp.h:243 [inline] kmem_getpages mm/slab.c:1363 [inline] cache_grow_begin+0x75/0x360 mm/slab.c:2569 cache_alloc_refill+0x27f/0x380 mm/slab.c:2942 ____cache_alloc mm/slab.c:3018 [inline] ____cache_alloc mm/slab.c:3001 [inline] __do_cache_alloc mm/slab.c:3246 [inline] slab_alloc mm/slab.c:3287 [inline] __do_kmalloc mm/slab.c:3684 [inline] __kmalloc+0x3a1/0x4a0 mm/slab.c:3695 kmalloc include/linux/slab.h:605 [inline] sk_prot_alloc+0x143/0x290 net/core/sock.c:1976 sk_alloc+0x36/0x770 net/core/sock.c:2029 __netlink_create+0x63/0x380 net/netlink/af_netlink.c:647 netlink_create+0x3ad/0x5e0 net/netlink/af_netlink.c:710 __sock_create+0x355/0x790 net/socket.c:1515 sock_create net/socket.c:1566 [inline] __sys_socket_create net/socket.c:1603 [inline] __sys_socket_create net/socket.c:1588 [inline] __sys_socket+0x12f/0x240 net/socket.c:1636 __do_sys_socket net/socket.c:1649 [inline] __se_sys_socket net/socket.c:1647 [inline] __x64_sys_socket+0x6f/0xb0 net/socket.c:1647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1449 [inline] free_pcp_prepare+0x5e4/0xd20 mm/page_alloc.c:1499 free_unref_page_prepare mm/page_alloc.c:3380 [inline] free_unref_page+0x19/0x4d0 mm/page_alloc.c:3476 mm_free_pgd kernel/fork.c:737 [inline] __mmdrop+0xcb/0x3f0 kernel/fork.c:788 mmdrop include/linux/sched/mm.h:50 [inline] mmdrop_sched include/linux/sched/mm.h:78 [inline] finish_task_switch.isra.0+0x6cc/0xc70 kernel/sched/core.c:5087 context_switch kernel/sched/core.c:5185 [inline] __schedule+0xae7/0x52b0 kernel/sched/core.c:6494 schedule+0xda/0x1b0 kernel/sched/core.c:6570 schedule_hrtimeout_range_clock+0x343/0x390 kernel/time/hrtimer.c:2296 ep_poll fs/eventpoll.c:1878 [inline] do_epoll_wait+0x12ba/0x1950 fs/eventpoll.c:2256 __do_sys_epoll_wait fs/eventpoll.c:2268 [inline] __se_sys_epoll_wait fs/eventpoll.c:2263 [inline] __x64_sys_epoll_wait+0x158/0x270 fs/eventpoll.c:2263 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff8880256faf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880256faf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880256fb000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880256fb080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880256fb100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================
