================================================================== BUG: KASAN: slab-use-after-free in pwq_release_workfn+0x339/0x380 kernel/workqueue.c:4124 Read of size 4 at addr ffff88807d7849c0 by task pool_workqueue_/3 CPU: 1 PID: 3 Comm: pool_workqueue_ Not tainted 6.6.0-rc1-syzkaller-00156-gf2fa1c812c91 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xc4/0x620 mm/kasan/report.c:475 kasan_report+0xda/0x110 mm/kasan/report.c:588 pwq_release_workfn+0x339/0x380 kernel/workqueue.c:4124 kthread_worker_fn+0x2fc/0xa80 kernel/kthread.c:823 kthread+0x33a/0x430 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Allocated by task 20181: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:599 [inline] kzalloc include/linux/slab.h:720 [inline] alloc_workqueue+0x16f/0x1490 kernel/workqueue.c:4684 nbd_dev_add+0x452/0xcb0 drivers/block/nbd.c:1794 nbd_genl_connect+0x74f/0x1ca0 drivers/block/nbd.c:1969 genl_family_rcv_msg_doit+0x1fc/0x2e0 net/netlink/genetlink.c:971 genl_family_rcv_msg net/netlink/genetlink.c:1051 [inline] genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1066 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2545 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1075 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline] netlink_unicast+0x536/0x810 net/netlink/af_netlink.c:1368 netlink_sendmsg+0x93c/0xe40 net/netlink/af_netlink.c:1910 sock_sendmsg_nosec net/socket.c:730 [inline] sock_sendmsg+0xd9/0x180 net/socket.c:753 ____sys_sendmsg+0x6ac/0x940 net/socket.c:2541 ___sys_sendmsg+0x135/0x1d0 net/socket.c:2595 __sys_sendmsg+0x117/0x1e0 net/socket.c:2624 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 20181: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x15b/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook+0x114/0x1e0 mm/slub.c:1826 slab_free mm/slub.c:3809 [inline] __kmem_cache_free+0xb8/0x2f0 mm/slub.c:3822 alloc_workqueue+0xe76/0x1490 kernel/workqueue.c:4746 nbd_dev_add+0x452/0xcb0 drivers/block/nbd.c:1794 nbd_genl_connect+0x74f/0x1ca0 drivers/block/nbd.c:1969 genl_family_rcv_msg_doit+0x1fc/0x2e0 net/netlink/genetlink.c:971 genl_family_rcv_msg net/netlink/genetlink.c:1051 [inline] genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1066 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2545 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1075 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline] netlink_unicast+0x536/0x810 net/netlink/af_netlink.c:1368 netlink_sendmsg+0x93c/0xe40 net/netlink/af_netlink.c:1910 sock_sendmsg_nosec net/socket.c:730 [inline] sock_sendmsg+0xd9/0x180 net/socket.c:753 ____sys_sendmsg+0x6ac/0x940 net/socket.c:2541 ___sys_sendmsg+0x135/0x1d0 net/socket.c:2595 __sys_sendmsg+0x117/0x1e0 net/socket.c:2624 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff88807d784800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 448 bytes inside of freed 512-byte region [ffff88807d784800, ffff88807d784a00) The buggy address belongs to the physical page: page:ffffea0001f5e100 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7d784 head:ffffea0001f5e100 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888012c41c80 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 18313, tgid 18310 (syz-executor.1), ts 487765929623, free_ts 486816879326 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2cf/0x340 mm/page_alloc.c:1536 prep_new_page mm/page_alloc.c:1543 [inline] get_page_from_freelist+0xee0/0x2f20 mm/page_alloc.c:3170 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4426 alloc_pages+0x1a9/0x270 mm/mempolicy.c:2298 alloc_slab_page mm/slub.c:1870 [inline] allocate_slab+0x251/0x380 mm/slub.c:2017 new_slab mm/slub.c:2070 [inline] ___slab_alloc+0x8be/0x1570 mm/slub.c:3223 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322 __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] __kmem_cache_alloc_node+0x137/0x350 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1022 [inline] __kmalloc_node_track_caller+0x50/0x100 mm/slab_common.c:1043 kmemdup+0x29/0x60 mm/util.c:131 kmemdup include/linux/fortify-string.h:765 [inline] cache_create_net+0x2b/0x220 net/sunrpc/cache.c:1745 rsc_cache_create_net net/sunrpc/auth_gss/svcauth_gss.c:2062 [inline] gss_svc_init_net+0x69/0x660 net/sunrpc/auth_gss/svcauth_gss.c:2090 ops_init+0xb9/0x650 net/core/net_namespace.c:136 setup_net+0x422/0xa40 net/core/net_namespace.c:339 copy_net_ns+0x2fa/0x670 net/core/net_namespace.c:491 create_new_namespaces+0x3ea/0xb10 kernel/nsproxy.c:110 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1136 [inline] free_unref_page_prepare+0x476/0xa40 mm/page_alloc.c:2312 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2405 kvfree+0x47/0x50 mm/util.c:653 prealloc_destroy kernel/bpf/hashtab.c:375 [inline] htab_map_free+0x8ad/0xb20 kernel/bpf/hashtab.c:1540 bpf_map_free_deferred+0x192/0x3c0 kernel/bpf/syscall.c:699 process_one_work+0x887/0x15d0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8bb/0x1290 kernel/workqueue.c:2784 kthread+0x33a/0x430 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Memory state around the buggy address: ffff88807d784880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807d784900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807d784980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807d784a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807d784a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================