================================================================== BUG: KASAN: use-after-free in get_disk_and_module block/genhd.c:1787 [inline] BUG: KASAN: use-after-free in exact_lock+0x38/0xd0 block/genhd.c:677 Read of size 8 at addr ffff88810f47e460 by task syz.0.4124/15308 CPU: 1 PID: 15308 Comm: syz.0.4124 Tainted: G W 5.10.234-syzkaller-00023-g3f5f2283d684 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118 print_address_description+0x81/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0x179/0x1c0 mm/kasan/report.c:452 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309 get_disk_and_module block/genhd.c:1787 [inline] exact_lock+0x38/0xd0 block/genhd.c:677 kobj_lookup+0x294/0x430 drivers/base/map.c:119 get_gendisk+0xf7/0x3d0 block/genhd.c:1001 bdev_get_gendisk fs/block_dev.c:1110 [inline] __blkdev_get+0x18c/0x12f0 fs/block_dev.c:1474 blkdev_get fs/block_dev.c:1653 [inline] blkdev_get_by_path+0x25a/0x480 fs/block_dev.c:1690 mount_bdev+0x51/0x370 fs/super.c:1400 vfat_mount+0x34/0x40 fs/fat/namei_vfat.c:1057 legacy_get_tree+0xf1/0x190 fs/fs_context.c:593 vfs_get_tree+0x88/0x290 fs/super.c:1572 do_new_mount+0x2ba/0xb30 fs/namespace.c:2917 path_mount+0x56f/0xcb0 fs/namespace.c:3247 do_mount fs/namespace.c:3260 [inline] __do_sys_mount fs/namespace.c:3468 [inline] __se_sys_mount+0x2c4/0x3b0 fs/namespace.c:3445 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3445 do_syscall_64+0x34/0x70 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f0c8cac5169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0c8b12f038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f0c8ccddfa0 RCX: 00007f0c8cac5169 RDX: 0000400000001200 RSI: 00004000000000c0 RDI: 00004000000001c0 RBP: 00007f0c8cb462a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f0c8ccddfa0 R15: 00007ffe44667eb8 Allocated by task 14480: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:430 [inline] ____kasan_kmalloc+0xdb/0x110 mm/kasan/common.c:509 __kasan_kmalloc+0x9/0x10 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] __kmalloc+0x1aa/0x330 mm/slub.c:4033 kmalloc include/linux/slab.h:557 [inline] kzalloc include/linux/slab.h:664 [inline] __register_sysctl_table+0xea/0x1240 fs/proc/proc_sysctl.c:1319 register_net_sysctl+0x2c/0x40 net/sysctl_net.c:121 __devinet_sysctl_register+0x1d3/0x2a0 net/ipv4/devinet.c:2598 devinet_sysctl_register+0x16a/0x1e0 net/ipv4/devinet.c:2638 inetdev_init+0x266/0x470 net/ipv4/devinet.c:277 inetdev_event+0x205/0x1040 net/ipv4/devinet.c:1544 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0x8c/0xf0 kernel/notifier.c:410 call_netdevice_notifiers_info net/core/dev.c:2054 [inline] call_netdevice_notifiers_extack net/core/dev.c:2066 [inline] call_netdevice_notifiers+0x145/0x1b0 net/core/dev.c:2080 register_netdevice+0x1066/0x13f0 net/core/dev.c:10086 register_netdev+0x3c/0x50 net/core/dev.c:10179 loopback_net_init+0x74/0x150 drivers/net/loopback.c:216 ops_init+0x1cd/0x4a0 net/core/net_namespace.c:144 setup_net+0x367/0xbf0 net/core/net_namespace.c:345 copy_net_ns+0x32f/0x520 net/core/net_namespace.c:486 create_new_namespaces+0x410/0x660 kernel/nsproxy.c:110 copy_namespaces+0x1d1/0x220 kernel/nsproxy.c:179 copy_process+0x11a0/0x3340 kernel/fork.c:2186 kernel_clone+0x21e/0x9e0 kernel/fork.c:2574 __do_sys_clone kernel/fork.c:2700 [inline] __se_sys_clone kernel/fork.c:2684 [inline] __x64_sys_clone+0x23f/0x290 kernel/fork.c:2684 do_syscall_64+0x34/0x70 entry_SYSCALL_64_after_hwframe+0x61/0xcb Last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd3/0x100 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 kvfree_call_rcu+0x136/0x650 kernel/rcu/tree.c:3535 drop_sysctl_table+0x311/0x450 fs/proc/proc_sysctl.c:1680 unregister_sysctl_table+0x76/0x120 fs/proc/proc_sysctl.c:1718 unregister_net_sysctl_table+0x15/0x20 net/sysctl_net.c:127 __devinet_sysctl_unregister net/ipv4/devinet.c:2621 [inline] devinet_sysctl_unregister net/ipv4/devinet.c:2649 [inline] inetdev_destroy net/ipv4/devinet.c:326 [inline] inetdev_event+0x76f/0x1040 net/ipv4/devinet.c:1612 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0x8c/0xf0 kernel/notifier.c:410 call_netdevice_notifiers_info net/core/dev.c:2054 [inline] call_netdevice_notifiers_extack net/core/dev.c:2066 [inline] call_netdevice_notifiers net/core/dev.c:2080 [inline] unregister_netdevice_many+0xde7/0x17d0 net/core/dev.c:10766 default_device_exit_batch+0x38a/0x3f0 net/core/dev.c:11286 ops_exit_list net/core/net_namespace.c:190 [inline] cleanup_net+0x6e9/0xcb0 net/core/net_namespace.c:609 process_one_work+0x6dc/0xbd0 kernel/workqueue.c:2301 worker_thread+0xaea/0x1510 kernel/workqueue.c:2447 kthread+0x34b/0x3d0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Second to last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd3/0x100 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 __call_rcu kernel/rcu/tree.c:2976 [inline] call_rcu+0x135/0x11f0 kernel/rcu/tree.c:3050 netlink_release+0x13ad/0x17d0 net/netlink/af_netlink.c:796 __sock_release net/socket.c:597 [inline] sock_close+0xdf/0x270 net/socket.c:1286 __fput+0x33d/0x7b0 fs/file_table.c:281 ____fput+0x15/0x20 fs/file_table.c:314 task_work_run+0x129/0x190 kernel/task_work.c:189 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop+0xbf/0xd0 kernel/entry/common.c:172 exit_to_user_mode_prepare kernel/entry/common.c:199 [inline] syscall_exit_to_user_mode+0xa2/0x1a0 kernel/entry/common.c:274 do_syscall_64+0x40/0x70 arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff88810f47e000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1120 bytes inside of 2048-byte region [ffff88810f47e000, ffff88810f47e800) The buggy address belongs to the page: page:ffffea00043d1e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88810f47c000 pfn:0x10f478 head:ffffea00043d1e00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 ffffea0004a2c008 ffffea0004952e08 ffff888100042d80 raw: ffff88810f47c000 0000000000080006 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 0x1d2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 285, ts 24516177749, free_ts 24511134339 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x166/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x2d8c/0x2f30 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x435/0xaf0 mm/page_alloc.c:5348 allocate_slab mm/slub.c:1808 [inline] new_slab+0x80/0x400 mm/slub.c:1869 new_slab_objects mm/slub.c:2627 [inline] ___slab_alloc+0x302/0x4b0 mm/slub.c:2791 __slab_alloc+0x63/0xa0 mm/slub.c:2831 slab_alloc_node mm/slub.c:2913 [inline] slab_alloc mm/slub.c:2955 [inline] __kmalloc_track_caller+0x1f8/0x320 mm/slub.c:4536 __kmalloc_reserve net/core/skbuff.c:144 [inline] __alloc_skb+0xbc/0x510 net/core/skbuff.c:212 alloc_skb include/linux/skbuff.h:1126 [inline] alloc_skb_with_frags+0xa1/0x570 net/core/skbuff.c:5993 sock_alloc_send_pskb+0x915/0xa50 net/core/sock.c:2388 sock_alloc_send_skb+0x32/0x40 net/core/sock.c:2405 mld_newpack+0x1b2/0x990 net/ipv6/mcast.c:1604 add_grhead net/ipv6/mcast.c:1707 [inline] add_grec+0xf63/0x13b0 net/ipv6/mcast.c:1838 mld_send_cr net/ipv6/mcast.c:1964 [inline] mld_ifc_timer_expire+0x73e/0xbf0 net/ipv6/mcast.c:2471 call_timer_fn+0x3b/0x2d0 kernel/time/timer.c:1450 expire_timers kernel/time/timer.c:1495 [inline] __run_timers+0x72a/0xa10 kernel/time/timer.c:1789 page last free stack trace: reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1349 [inline] __free_pages_ok+0x82c/0x850 mm/page_alloc.c:1629 free_the_page+0x76/0x370 mm/page_alloc.c:5409 __free_pages+0x67/0xc0 mm/page_alloc.c:5418 __free_slab+0xcf/0x190 mm/slub.c:1894 free_slab mm/slub.c:1909 [inline] discard_slab mm/slub.c:1915 [inline] unfreeze_partials+0x15e/0x190 mm/slub.c:2410 put_cpu_partial+0xbf/0x180 mm/slub.c:2446 __slab_free+0x2c8/0x3a0 mm/slub.c:3095 do_slab_free mm/slub.c:3191 [inline] ___cache_free+0x111/0x130 mm/slub.c:3210 qlink_free+0x50/0x90 mm/kasan/quarantine.c:157 qlist_free_all+0x47/0xb0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x15a/0x170 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xe0 mm/kasan/common.c:440 kasan_slab_alloc include/linux/kasan.h:244 [inline] slab_post_alloc_hook+0x61/0x2f0 mm/slab.h:583 slab_alloc_node mm/slub.c:2947 [inline] slab_alloc mm/slub.c:2955 [inline] kmem_cache_alloc+0x168/0x2e0 mm/slub.c:2960 shmem_alloc_inode+0x1a/0x30 mm/shmem.c:3816 alloc_inode fs/inode.c:233 [inline] new_inode_pseudo+0x64/0x220 fs/inode.c:968 Memory state around the buggy address: ffff88810f47e300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88810f47e380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88810f47e400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88810f47e480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88810f47e500: fb fb fb fb fb fb fb fb fb fb fb 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