syzbot

9pnet: Found fid 1 not clunked
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BUG: KASAN: slab-use-after-free in p9_fid_destroy net/9p/client.c:885 [inline]
BUG: KASAN: slab-use-after-free in p9_client_destroy+0x183/0x660 net/9p/client.c:1071
Read of size 8 at addr ffff888019f41b00 by task syz-executor.0/15619

CPU: 1 PID: 15619 Comm: syz-executor.0 Not tainted 6.9.0-rc3-next-20240412-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 p9_fid_destroy net/9p/client.c:885 [inline]
 p9_client_destroy+0x183/0x660 net/9p/client.c:1071
 v9fs_session_close+0x51/0x210 fs/9p/v9fs.c:506
 v9fs_kill_super+0x5c/0x90 fs/9p/vfs_super.c:196
 deactivate_locked_super+0xc4/0x130 fs/super.c:472
 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1267
 task_work_run+0x24f/0x310 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+0x168/0x370 kernel/entry/common.c:218
 do_syscall_64+0x10a/0x250 arch/x86/entry/common.c:111
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f259827f197
Code: b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 b0 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007fffc0ec82b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f259827f197
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffc0ec8370
RBP: 00007fffc0ec8370 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fffc0ec9430
R13: 00007f25982c93b9 R14: 00000000000acd5e R15: 0000000000000013
 </TASK>

Allocated by task 17012:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 kmalloc_trace_noprof+0x19c/0x2b0 mm/slub.c:4109
 kmalloc_noprof include/linux/slab.h:660 [inline]
 kzalloc_noprof include/linux/slab.h:775 [inline]
 p9_fid_create+0x4f/0x230 net/9p/client.c:854
 p9_client_walk+0x103/0x690 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+0x285/0xa60 fs/9p/vfs_file.c:56
 do_dentry_open+0x907/0x15f0 fs/open.c:955
 do_open fs/namei.c:3642 [inline]
 path_openat+0x289f/0x3280 fs/namei.c:3799
 do_filp_open+0x235/0x490 fs/namei.c:3826
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1406
 do_sys_open fs/open.c:1421 [inline]
 __do_sys_creat fs/open.c:1497 [inline]
 __se_sys_creat fs/open.c:1491 [inline]
 __x64_sys_creat+0x123/0x170 fs/open.c:1491
 do_syscall_x64 arch/x86/entry/common.c:74 [inline]
 do_syscall_64+0xfa/0x250 arch/x86/entry/common.c:105
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 12:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240
 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2190 [inline]
 slab_free mm/slub.c:4393 [inline]
 kfree+0x149/0x350 mm/slub.c:4514
 p9_fid_destroy net/9p/client.c:890 [inline]
 p9_client_clunk+0x1ce/0x260 net/9p/client.c:1457
 netfs_free_request+0x244/0x5e0 fs/netfs/objects.c:133
 netfs_write_collection_worker+0x5079/0x5630 fs/netfs/write_collect.c:701
 process_one_work kernel/workqueue.c:3218 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3299
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3380
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

The buggy address belongs to the object at ffff888019f41b00
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 0 bytes inside of
 freed 96-byte region [ffff888019f41b00, ffff888019f41b60)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x19f41
anon flags: 0xfff80000000000(node=0|zone=1|lastcpupid=0xfff)
page_type: 0xffffefff(slab)
raw: 00fff80000000000 ffff888015041780 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000200020 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 8, tgid -112890094 (kworker/0:0), ts 8, free_ts 77104165234
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1474
 prep_new_page mm/page_alloc.c:1482 [inline]
 get_page_from_freelist+0x2ce2/0x2d90 mm/page_alloc.c:3444
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4702
 __alloc_pages_node_noprof include/linux/gfp.h:244 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:271 [inline]
 alloc_slab_page+0x5f/0x120 mm/slub.c:2259
 allocate_slab+0x5a/0x2e0 mm/slub.c:2422
 new_slab mm/slub.c:2475 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3624
 __slab_alloc+0x58/0xa0 mm/slub.c:3714
 __slab_alloc_node mm/slub.c:3767 [inline]
 slab_alloc_node mm/slub.c:3945 [inline]
 kmalloc_trace_noprof+0x1d5/0x2b0 mm/slub.c:4104
 kmalloc_noprof include/linux/slab.h:660 [inline]
 kzalloc_noprof include/linux/slab.h:775 [inline]
 nsim_fib4_rt_create drivers/net/netdevsim/fib.c:280 [inline]
 nsim_fib4_rt_insert drivers/net/netdevsim/fib.c:426 [inline]
 nsim_fib4_event drivers/net/netdevsim/fib.c:464 [inline]
 nsim_fib_event drivers/net/netdevsim/fib.c:884 [inline]
 nsim_fib_event_work+0xe17/0x4130 drivers/net/netdevsim/fib.c:1492
 process_one_work kernel/workqueue.c:3218 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3299
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3380
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
page last free pid 5110 tgid 5110 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1094 [inline]
 free_unref_page+0xd22/0xea0 mm/page_alloc.c:2607
 discard_slab mm/slub.c:2521 [inline]
 __put_partials+0xeb/0x130 mm/slub.c:2989
 put_cpu_partial+0x17c/0x250 mm/slub.c:3064
 __slab_free+0x2ea/0x3d0 mm/slub.c:4263
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9e/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:322
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3897 [inline]
 slab_alloc_node mm/slub.c:3957 [inline]
 kmem_cache_alloc_node_noprof+0x16b/0x310 mm/slub.c:4000
 __alloc_skb+0x1c3/0x440 net/core/skbuff.c:658
 alloc_skb include/linux/skbuff.h:1313 [inline]
 nlmsg_new include/net/netlink.h:1015 [inline]
 netlink_ack+0x399/0x12b0 net/netlink/af_netlink.c:2496
 netlink_rcv_skb+0x262/0x430 net/netlink/af_netlink.c:2565
 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
 netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361
 netlink_sendmsg+0x8e1/0xcb0 net/netlink/af_netlink.c:1905
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:745
 __sys_sendto+0x3a4/0x4f0 net/socket.c:2191
 __do_sys_sendto net/socket.c:2203 [inline]
 __se_sys_sendto net/socket.c:2199 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2199

Memory state around the buggy address:
 ffff888019f41a00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
 ffff888019f41a80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff888019f41b00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                   ^
 ffff888019f41b80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
 ffff888019f41c00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
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