================================================================== BUG: KASAN: use-after-free in __io_remove_buffers.part.0+0x3c6/0x4f0 io_uring/kbuf.c:217 Read of size 2 at addr ffff88807d146012 by task kworker/u4:27/28417 CPU: 0 PID: 28417 Comm: kworker/u4:27 Not tainted 5.19.0-rc4-next-20220628-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Workqueue: events_unbound io_ring_exit_work Call Trace: __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/0x719 mm/kasan/report.c:433 kasan_report+0xbe/0x1f0 mm/kasan/report.c:495 __io_remove_buffers.part.0+0x3c6/0x4f0 io_uring/kbuf.c:217 __io_remove_buffers io_uring/kbuf.c:255 [inline] io_destroy_buffers+0x9a/0x3b0 io_uring/kbuf.c:255 io_ring_ctx_free io_uring/io_uring.c:2477 [inline] io_ring_exit_work+0x784/0xc7c io_uring/io_uring.c:2661 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302 Allocated by task 31029: 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:436 [inline] ____kasan_kmalloc mm/kasan/common.c:515 [inline] ____kasan_kmalloc mm/kasan/common.c:474 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:524 kmalloc include/linux/slab.h:600 [inline] kmalloc_array include/linux/slab.h:639 [inline] kcalloc include/linux/slab.h:671 [inline] io_init_bl_list+0x4c/0x139 io_uring/kbuf.c:195 io_register_pbuf_ring.cold+0x11/0x84 io_uring/kbuf.c:495 __io_uring_register io_uring/io_uring.c:3855 [inline] __do_sys_io_uring_register+0x6b2/0x1030 io_uring/io_uring.c:3897 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+0x46/0xb0 Freed by task 31029: 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:366 [inline] ____kasan_slab_free+0x166/0x1c0 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1754 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1780 slab_free mm/slub.c:3534 [inline] kfree+0xe2/0x4d0 mm/slub.c:4562 io_register_pbuf_ring+0x4e9/0x5d0 io_uring/kbuf.c:515 __io_uring_register io_uring/io_uring.c:3855 [inline] __do_sys_io_uring_register+0x6b2/0x1030 io_uring/io_uring.c:3897 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+0x46/0xb0 Last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 call_rcu+0x99/0x790 kernel/rcu/tree.c:2793 netlink_release+0xf08/0x1db0 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:317 task_work_run+0xdd/0x1a0 kernel/task_work.c:177 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:169 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Second to last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 call_rcu+0x99/0x790 kernel/rcu/tree.c:2793 netlink_release+0xf08/0x1db0 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:317 task_work_run+0xdd/0x1a0 kernel/task_work.c:177 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:169 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x46/0xb0 The buggy address belongs to the object at ffff88807d146000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 18 bytes inside of 2048-byte region [ffff88807d146000, ffff88807d146800) The buggy address belongs to the physical page: page:ffffea0001f45000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7d140 head:ffffea0001f45000 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000001 ffff888011842000 raw: 0000000000000000 0000000080080008 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3637, tgid 3637 (syz-executor.4), ts 237310780282, free_ts 237272532724 prep_new_page mm/page_alloc.c:2535 [inline] get_page_from_freelist+0x210d/0x3a30 mm/page_alloc.c:4282 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5506 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2280 alloc_slab_page mm/slub.c:1824 [inline] allocate_slab+0x27e/0x3d0 mm/slub.c:1969 new_slab mm/slub.c:2029 [inline] ___slab_alloc+0x89d/0xef0 mm/slub.c:3031 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3118 slab_alloc_node mm/slub.c:3209 [inline] slab_alloc mm/slub.c:3251 [inline] kmem_cache_alloc_trace+0x323/0x3e0 mm/slub.c:3282 kmalloc include/linux/slab.h:600 [inline] rtnl_newlink+0x46/0xa0 net/core/rtnetlink.c:3589 rtnetlink_rcv_msg+0x43a/0xc90 net/core/rtnetlink.c:6089 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 __sys_sendto+0x21a/0x320 net/socket.c:2116 __do_sys_sendto net/socket.c:2128 [inline] __se_sys_sendto net/socket.c:2124 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2124 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1453 [inline] free_pcp_prepare+0x5e4/0xd20 mm/page_alloc.c:1503 free_unref_page_prepare mm/page_alloc.c:3383 [inline] free_unref_page+0x19/0x4d0 mm/page_alloc.c:3479 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2548 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:446 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:736 [inline] slab_alloc_node mm/slub.c:3243 [inline] slab_alloc mm/slub.c:3251 [inline] __kmem_cache_alloc_lru mm/slub.c:3258 [inline] kmem_cache_alloc+0x2d6/0x4c0 mm/slub.c:3268 kmem_cache_zalloc include/linux/slab.h:723 [inline] __kernfs_new_node+0xd4/0x8b0 fs/kernfs/dir.c:593 kernfs_new_node+0x93/0x120 fs/kernfs/dir.c:655 kernfs_create_link+0xcb/0x230 fs/kernfs/symlink.c:39 sysfs_do_create_link_sd+0x90/0x140 fs/sysfs/symlink.c:44 sysfs_do_create_link fs/sysfs/symlink.c:80 [inline] sysfs_create_link+0x5f/0xc0 fs/sysfs/symlink.c:92 device_add_class_symlinks drivers/base/core.c:3247 [inline] device_add+0x700/0x1e90 drivers/base/core.c:3453 netdev_register_kobject+0x181/0x400 net/core/net-sysfs.c:2015 register_netdevice+0xd9d/0x15e0 net/core/dev.c:10065 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:317 [inline] nsim_create+0x3c3/0x520 drivers/net/netdevsim/netdev.c:365 Memory state around the buggy address: ffff88807d145f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807d145f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88807d146000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807d146080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807d146100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================