================================================================== 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 ffff8881009a6460 by task syz.0.7044/26956 CPU: 0 PID: 26956 Comm: syz.0.7044 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_open+0x241/0x480 fs/block_dev.c:1770 do_dentry_open+0x7c1/0x10d0 fs/open.c:819 vfs_open+0x73/0x80 fs/open.c:942 do_open fs/namei.c:3391 [inline] path_openat+0x2660/0x3000 fs/namei.c:3509 do_filp_open+0x21c/0x460 fs/namei.c:3536 do_sys_openat2+0x13f/0x710 fs/open.c:1217 do_sys_open fs/open.c:1233 [inline] __do_sys_openat fs/open.c:1249 [inline] __se_sys_openat fs/open.c:1244 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1244 do_syscall_64+0x34/0x70 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fadd0d0e169 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:00007fadcf357038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fadd0f27080 RCX: 00007fadd0d0e169 RDX: 0000000000000000 RSI: 0000400000004280 RDI: ffffffffffffff9c RBP: 00007fadd0d8f2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fadd0f27080 R15: 00007ffe0cf8bef8 Allocated by task 26209: 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_array include/linux/slab.h:592 [inline] kcalloc include/linux/slab.h:603 [inline] multiq_init+0x14d/0x2d0 net/sched/sch_multiq.c:252 qdisc_create+0x879/0x12d0 net/sched/sch_api.c:1269 tc_modify_qdisc+0x8e2/0x1470 rtnetlink_rcv_msg+0x955/0xc50 net/core/rtnetlink.c:5607 netlink_rcv_skb+0x1cf/0x410 net/netlink/af_netlink.c:2485 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5625 netlink_unicast_kernel net/netlink/af_netlink.c:1307 [inline] netlink_unicast+0x8df/0xac0 net/netlink/af_netlink.c:1333 netlink_sendmsg+0xa46/0xd00 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:652 [inline] __sock_sendmsg net/socket.c:664 [inline] ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2376 ___sys_sendmsg+0x252/0x2e0 net/socket.c:2430 __sys_sendmsg net/socket.c:2459 [inline] __do_sys_sendmsg net/socket.c:2468 [inline] __se_sys_sendmsg+0x1b1/0x280 net/socket.c:2466 __x64_sys_sendmsg+0x7b/0x90 net/socket.c:2466 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 insert_work+0x56/0x310 kernel/workqueue.c:1352 __queue_work+0x970/0xd10 kernel/workqueue.c:1518 __queue_delayed_work+0x182/0x1f0 kernel/workqueue.c:1672 mod_delayed_work_on+0xff/0x190 kernel/workqueue.c:1746 mod_delayed_work include/linux/workqueue.h:545 [inline] wb_shutdown+0x176/0x1c0 mm/backing-dev.c:351 bdi_unregister+0x189/0x5b0 mm/backing-dev.c:880 generic_shutdown_super+0x2bf/0x320 fs/super.c:480 kill_anon_super+0x3d/0x70 fs/super.c:1131 v9fs_kill_super+0x4c/0x90 fs/9p/vfs_super.c:221 deactivate_locked_super+0xad/0x110 fs/super.c:335 v9fs_mount+0x544/0x7b0 fs/9p/vfs_super.c:205 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 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 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 ip6gre_exit_batch_net+0x5b2/0x600 net/ipv6/ip6_gre.c:1649 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 The buggy address belongs to the object at ffff8881009a6000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1120 bytes inside of 2048-byte region [ffff8881009a6000, ffff8881009a6800) The buggy address belongs to the page: page:ffffea0004026800 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8881009a2000 pfn:0x1009a0 head:ffffea0004026800 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 ffffea0004b75808 ffffea00044a6608 ffff888100042d80 raw: ffff8881009a2000 0000000000080005 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, ts 1968472226, free_ts 0 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] kmem_cache_alloc_trace+0x1bd/0x2e0 mm/slub.c:2972 kmem_cache_alloc_node_trace include/linux/slab.h:440 [inline] kmalloc_node include/linux/slab.h:570 [inline] kzalloc_node include/linux/slab.h:675 [inline] bdi_alloc+0x4e/0x110 mm/backing-dev.c:746 blk_alloc_queue+0x112/0x640 block/blk-core.c:535 brd_alloc+0x100/0x400 drivers/block/brd.c:383 brd_init+0x125/0x474 drivers/block/brd.c:517 do_one_initcall+0x189/0x620 init/main.c:1197 do_initcall_level+0x186/0x304 init/main.c:1270 do_initcalls+0x4e/0x8e init/main.c:1286 do_basic_setup+0x88/0x91 init/main.c:1306 kernel_init_freeable+0x2be/0x3f5 init/main.c:1510 page_owner free stack trace missing Memory state around the buggy address: ffff8881009a6300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881009a6380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881009a6400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881009a6480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881009a6500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================