================================================================== BUG: KASAN: slab-use-after-free in p9_fid_destroy+0xb5/0xd0 net/9p/client.c:885 Read of size 8 at addr ffff8881082e6780 by task kworker/u32:8/1095 CPU: 1 PID: 1095 Comm: kworker/u32:8 Not tainted 6.10.0-rc1-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Workqueue: events_unbound netfs_write_collection_worker Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc3/0x620 mm/kasan/report.c:488 kasan_report+0xd9/0x110 mm/kasan/report.c:601 p9_fid_destroy+0xb5/0xd0 net/9p/client.c:885 p9_client_clunk+0x12a/0x170 net/9p/client.c:1457 p9_fid_put include/net/9p/client.h:280 [inline] v9fs_free_request+0xdc/0x110 fs/9p/vfs_addr.c:138 netfs_free_request+0x22c/0x690 fs/netfs/objects.c:133 netfs_put_request+0x19b/0x1f0 fs/netfs/objects.c:165 netfs_write_collection_worker+0x19d0/0x59e0 fs/netfs/write_collect.c:701 process_one_work+0x9fb/0x1b60 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Allocated by task 15556: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:387 kmalloc_noprof include/linux/slab.h:660 [inline] kzalloc_noprof include/linux/slab.h:778 [inline] p9_fid_create+0x45/0x470 net/9p/client.c:854 p9_client_walk+0xc6/0x550 net/9p/client.c:1155 clone_fid fs/9p/fid.h:23 [inline] v9fs_fid_clone fs/9p/fid.h:33 [inline] v9fs_file_open+0x5b5/0xae0 fs/9p/vfs_file.c:56 do_dentry_open+0x910/0x1930 fs/open.c:955 do_open fs/namei.c:3650 [inline] path_openat+0x1e3a/0x29f0 fs/namei.c:3807 do_filp_open+0x1dc/0x430 fs/namei.c:3834 do_sys_openat2+0x17a/0x1e0 fs/open.c:1405 do_sys_open fs/open.c:1420 [inline] __do_sys_openat fs/open.c:1436 [inline] __se_sys_openat fs/open.c:1431 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1431 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 15218: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 poison_slab_object+0xf7/0x160 mm/kasan/common.c:240 __kasan_slab_free+0x32/0x50 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2195 [inline] slab_free mm/slub.c:4436 [inline] kfree+0x12a/0x3b0 mm/slub.c:4557 p9_client_destroy+0x14c/0x480 net/9p/client.c:1071 v9fs_session_close+0x49/0x2d0 fs/9p/v9fs.c:506 v9fs_kill_super+0x4d/0xa0 fs/9p/vfs_super.c:196 deactivate_locked_super+0xbe/0x1a0 fs/super.c:473 deactivate_super+0xde/0x100 fs/super.c:506 cleanup_mnt+0x222/0x450 fs/namespace.c:1267 task_work_run+0x14e/0x250 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8881082e6780 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 0 bytes inside of freed 96-byte region [ffff8881082e6780, ffff8881082e67e0) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8881082e6080 pfn:0x1082e6 flags: 0x57ff00000000200(workingset|node=1|zone=2|lastcpupid=0x7ff) page_type: 0xffffefff(slab) raw: 057ff00000000200 ffff888015442280 ffffea0004205910 ffffea000420ee50 raw: ffff8881082e6080 000000000020001f 00000001ffffefff 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 0x352800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL|__GFP_THISNODE), pid 9698, tgid 9697 (syz-executor.0), ts 219862030165, free_ts 197990766759 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1468 prep_new_page mm/page_alloc.c:1476 [inline] get_page_from_freelist+0x136a/0x2df0 mm/page_alloc.c:3402 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4660 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] alloc_slab_page+0x56/0x110 mm/slub.c:2264 allocate_slab mm/slub.c:2427 [inline] new_slab+0x84/0x260 mm/slub.c:2480 ___slab_alloc+0xdac/0x1870 mm/slub.c:3666 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3756 __slab_alloc_node mm/slub.c:3809 [inline] slab_alloc_node mm/slub.c:3988 [inline] kmalloc_node_trace_noprof+0xf1/0x350 mm/slub.c:4160 kmalloc_node_noprof include/linux/slab.h:677 [inline] alloc_node_nr_active kernel/workqueue.c:4833 [inline] alloc_workqueue+0x70f/0x1ca0 kernel/workqueue.c:5713 btrfs_alloc_workqueue+0x21c/0x510 fs/btrfs/async-thread.c:112 btrfs_init_workqueues fs/btrfs/disk-io.c:1985 [inline] open_ctree+0x139d/0x5330 fs/btrfs/disk-io.c:3362 btrfs_fill_super fs/btrfs/super.c:946 [inline] btrfs_get_tree_super fs/btrfs/super.c:1863 [inline] btrfs_get_tree+0x11e9/0x1b90 fs/btrfs/super.c:2089 vfs_get_tree+0x8f/0x380 fs/super.c:1780 fc_mount+0x16/0xc0 fs/namespace.c:1125 btrfs_get_tree_subvol fs/btrfs/super.c:2052 [inline] btrfs_get_tree+0xa53/0x1b90 fs/btrfs/super.c:2090 vfs_get_tree+0x8f/0x380 fs/super.c:1780 page last free pid 9261 tgid 9260 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1088 [inline] free_unref_page+0x64a/0xe40 mm/page_alloc.c:2565 vfree+0x181/0x7a0 mm/vmalloc.c:3346 ebt_free_table_info net/bridge/netfilter/ebtables.c:388 [inline] ebt_free_table_info net/bridge/netfilter/ebtables.c:382 [inline] do_replace_finish+0x874/0x22c0 net/bridge/netfilter/ebtables.c:1103 do_replace+0x351/0x500 net/bridge/netfilter/ebtables.c:1153 do_ebt_set_ctl+0x470/0x580 net/bridge/netfilter/ebtables.c:2527 nf_setsockopt+0x8a/0xf0 net/netfilter/nf_sockopt.c:101 ip_setsockopt+0xcb/0xf0 net/ipv4/ip_sockglue.c:1424 udp_setsockopt+0x7d/0xd0 net/ipv4/udp.c:2805 do_sock_setsockopt+0x222/0x480 net/socket.c:2312 __sys_setsockopt+0x1a4/0x270 net/socket.c:2335 __do_sys_setsockopt net/socket.c:2344 [inline] __se_sys_setsockopt net/socket.c:2341 [inline] __x64_sys_setsockopt+0xbd/0x160 net/socket.c:2341 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff8881082e6680: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8881082e6700: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc >ffff8881082e6780: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff8881082e6800: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc ffff8881082e6880: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ==================================================================