================================================================== BUG: KASAN: use-after-free in get_disk_and_module block/genhd.c:1787 [inline] BUG: KASAN: use-after-free in exact_lock+0x38/0xc0 block/genhd.c:677 Read of size 8 at addr ffff88812de08460 by task syz.1.5875/21091 CPU: 0 PID: 21091 Comm: syz.1.5875 Tainted: G W 5.10.238-syzkaller-00008-g59e9a7228857 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x169/0x1d8 lib/dump_stack.c:118 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0xe2/0x130 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+0x38/0xc0 block/genhd.c:677 kobj_lookup+0x298/0x430 drivers/base/map.c:119 get_gendisk+0xe9/0x340 block/genhd.c:1001 bdev_get_gendisk fs/block_dev.c:1110 [inline] __blkdev_get+0x1b0/0x12f0 fs/block_dev.c:1474 blkdev_get fs/block_dev.c:1653 [inline] blkdev_get_by_path+0x253/0x470 fs/block_dev.c:1690 mount_bdev+0x50/0x3a0 fs/super.c:1400 vfat_mount+0x34/0x40 fs/fat/namei_vfat.c:1057 legacy_get_tree+0xed/0x190 fs/fs_context.c:593 vfs_get_tree+0x89/0x260 fs/super.c:1572 do_new_mount+0x25a/0xa20 fs/namespace.c:2915 path_mount+0x572/0xc80 fs/namespace.c:3245 do_mount fs/namespace.c:3258 [inline] __do_sys_mount fs/namespace.c:3466 [inline] __se_sys_mount+0x318/0x380 fs/namespace.c:3443 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3443 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f6644d2c929 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:00007f6643374038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f6644f54080 RCX: 00007f6644d2c929 RDX: 0000200000001200 RSI: 00002000000000c0 RDI: 00002000000001c0 RBP: 00007f6644daeb39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f6644f54080 R15: 00007ffe9b486d18 Allocated by task 19615: 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 mm/kasan/common.c:509 [inline] __kasan_kmalloc+0xda/0x110 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] __kmalloc+0x1a7/0x330 mm/slub.c:4033 kmalloc include/linux/slab.h:557 [inline] sk_prot_alloc+0xb2/0x340 net/core/sock.c:1716 sk_alloc+0x38/0x4e0 net/core/sock.c:1774 __netlink_create net/netlink/af_netlink.c:622 [inline] __netlink_kernel_create+0x186/0x940 net/netlink/af_netlink.c:2027 netlink_kernel_create include/linux/netlink.h:60 [inline] audit_net_init+0xf1/0x210 kernel/audit.c:1660 ops_init+0x1ba/0x4a0 net/core/net_namespace.c:144 setup_net+0x36d/0xb50 net/core/net_namespace.c:345 copy_net_ns+0x314/0x520 net/core/net_namespace.c:486 create_new_namespaces+0x3a2/0x650 kernel/nsproxy.c:110 copy_namespaces+0x1d1/0x220 kernel/nsproxy.c:179 copy_process+0x11b8/0x32c0 kernel/fork.c:2271 kernel_clone+0x23f/0x940 kernel/fork.c:2650 __do_sys_clone kernel/fork.c:2776 [inline] __se_sys_clone kernel/fork.c:2760 [inline] __x64_sys_clone+0x176/0x1d0 kernel/fork.c:2760 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 24: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4a/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:362 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370 kasan_slab_free include/linux/kasan.h:220 [inline] slab_free_hook mm/slub.c:1595 [inline] slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1621 slab_free mm/slub.c:3203 [inline] kfree+0xc0/0x270 mm/slub.c:4191 skb_free_head net/core/skbuff.c:606 [inline] skb_release_data+0x532/0x670 net/core/skbuff.c:626 skb_release_all net/core/skbuff.c:680 [inline] __kfree_skb net/core/skbuff.c:694 [inline] kfree_skb+0xb9/0x2f0 net/core/skbuff.c:713 kauditd_hold_skb+0x116/0x210 kernel/audit.c:614 kauditd_send_queue+0x289/0x2d0 kernel/audit.c:769 kauditd_thread+0x4dc/0x850 kernel/audit.c:893 kthread+0x346/0x3d0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd2/0x100 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+0x105/0x1040 kernel/rcu/tree.c:3050 netlink_release+0x1288/0x1690 net/netlink/af_netlink.c:796 __sock_release net/socket.c:597 [inline] sock_release+0x7f/0x140 net/socket.c:625 netlink_kernel_release+0x4d/0x60 net/netlink/af_netlink.c:2089 audit_net_exit+0x86/0x90 kernel/audit.c:1681 ops_exit_list net/core/net_namespace.c:185 [inline] cleanup_net+0x586/0xb70 net/core/net_namespace.c:609 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301 worker_thread+0xa6a/0x13b0 kernel/workqueue.c:2447 kthread+0x346/0x3d0 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+0x3a/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 insert_work+0x52/0x310 kernel/workqueue.c:1352 __queue_work+0x923/0xca0 kernel/workqueue.c:1518 queue_work_on+0xd5/0x130 kernel/workqueue.c:1545 queue_work include/linux/workqueue.h:515 [inline] schedule_work include/linux/workqueue.h:576 [inline] destroy_super_rcu+0xd1/0xe0 fs/super.c:172 rcu_do_batch+0x4df/0xa80 kernel/rcu/tree.c:2494 rcu_core+0x55f/0xd60 kernel/rcu/tree.c:2735 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2748 __do_softirq+0x255/0x563 kernel/softirq.c:309 The buggy address belongs to the object at ffff88812de08000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1120 bytes inside of 2048-byte region [ffff88812de08000, ffff88812de08800) The buggy address belongs to the page: page:ffffea0004b78200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12de08 head:ffffea0004b78200 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100042d80 raw: 0000000000000000 0000000000080008 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 4297, ts 154238919696, free_ts 154213935800 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x179/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x2235/0x23d0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x268/0x5f0 mm/page_alloc.c:5357 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1808 [inline] new_slab+0x84/0x3f0 mm/slub.c:1869 new_slab_objects mm/slub.c:2627 [inline] ___slab_alloc+0x2a6/0x450 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+0x1ef/0x320 mm/slub.c:4536 __kmalloc_reserve net/core/skbuff.c:144 [inline] __alloc_skb+0xdc/0x520 net/core/skbuff.c:212 alloc_skb include/linux/skbuff.h:1126 [inline] alloc_skb_with_frags+0xa2/0x560 net/core/skbuff.c:5993 sock_alloc_send_pskb+0x853/0x980 net/core/sock.c:2388 sock_alloc_send_skb+0x32/0x40 net/core/sock.c:2405 mld_newpack+0x193/0x9a0 net/ipv6/mcast.c:1604 add_grhead+0x5e/0x290 net/ipv6/mcast.c:1707 add_grec+0xd43/0x1100 net/ipv6/mcast.c:1838 mld_send_cr net/ipv6/mcast.c:1964 [inline] mld_ifc_timer_expire+0x770/0xc50 net/ipv6/mcast.c:2471 call_timer_fn+0x38/0x290 kernel/time/timer.c:1450 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+0x7fc/0x820 mm/page_alloc.c:1629 free_the_page mm/page_alloc.c:5418 [inline] __free_pages+0xdd/0x380 mm/page_alloc.c:5427 __free_slab+0xcf/0x190 mm/slub.c:1894 free_slab mm/slub.c:1909 [inline] discard_slab mm/slub.c:1915 [inline] unfreeze_partials+0x15f/0x190 mm/slub.c:2410 put_cpu_partial+0xc1/0x180 mm/slub.c:2446 __slab_free+0x2c9/0x3a0 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+0x5f/0xb0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x14a/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xf0 mm/kasan/common.c:440 kasan_slab_alloc include/linux/kasan.h:244 [inline] slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:583 slab_alloc_node mm/slub.c:2947 [inline] slab_alloc mm/slub.c:2955 [inline] kmem_cache_alloc_trace+0x160/0x2e0 mm/slub.c:2972 kmalloc include/linux/slab.h:552 [inline] kzalloc include/linux/slab.h:664 [inline] ____ip_mc_inc_group+0x190/0x820 net/ipv4/igmp.c:1452 __ip_mc_inc_group net/ipv4/igmp.c:1487 [inline] ip_mc_inc_group net/ipv4/igmp.c:1493 [inline] ip_mc_up+0x112/0x1f0 net/ipv4/igmp.c:1792 inetdev_event+0xc13/0x1030 net/ipv4/devinet.c:1588 Memory state around the buggy address: ffff88812de08300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88812de08380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88812de08400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88812de08480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88812de08500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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