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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 ffff8881009a3460 by task syz.8.2805/11297

CPU: 0 PID: 11297 Comm: syz.8.2805 Tainted: G        W         5.10.236-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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_open+0x208/0x430 fs/block_dev.c:1770
 do_dentry_open+0x793/0x1090 fs/open.c:819
 vfs_open+0x73/0x80 fs/open.c:942
 do_open fs/namei.c:3391 [inline]
 path_openat+0x27ad/0x3160 fs/namei.c:3509
 do_filp_open+0x1b3/0x3e0 fs/namei.c:3536
 do_sys_openat2+0x14c/0x6d0 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+0x136/0x160 fs/open.c:1244
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f33a7dc22d0
Code: 48 89 44 24 20 75 93 44 89 54 24 0c e8 49 94 02 00 44 8b 54 24 0c 89 da 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 38 44 89 c7 89 44 24 0c e8 9c 94 02 00 8b 44
RSP: 002b:00007f33a642bb70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000080082 RCX: 00007f33a7dc22d0
RDX: 0000000000080082 RSI: 00007f33a642bc10 RDI: 00000000ffffff9c
RBP: 00007f33a642bc10 R08: 0000000000000000 R09: 0023706f6f6c2f76
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f33a7feafa0 R15: 00007ffd6a7ec678

Allocated by task 9763:
 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]
 kzalloc include/linux/slab.h:664 [inline]
 __register_sysctl_table+0xeb/0x1250 fs/proc/proc_sysctl.c:1319
 register_net_sysctl+0x2c/0x40 net/sysctl_net.c:121
 __devinet_sysctl_register+0x2c4/0x390 net/ipv4/devinet.c:2599
 devinet_sysctl_register+0x169/0x1e0 net/ipv4/devinet.c:2639
 inetdev_init+0x273/0x480 net/ipv4/devinet.c:277
 inetdev_event+0x1f8/0x1030 net/ipv4/devinet.c:1545
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0x90/0x100 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+0x111/0x190 net/core/dev.c:2080
 register_netdevice+0x1043/0x13c0 net/core/dev.c:10086
 register_vlan_dev+0x2a0/0x5d0 net/8021q/vlan.c:177
 vlan_newlink+0x43a/0x5f0 net/8021q/vlan_netlink.c:195
 __rtnl_newlink net/core/rtnetlink.c:3482 [inline]
 rtnl_newlink+0x11bd/0x1640 net/core/rtnetlink.c:3530
 rtnetlink_rcv_msg+0x9db/0xb90 net/core/rtnetlink.c:5610
 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2485
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5628
 netlink_unicast_kernel net/netlink/af_netlink.c:1307 [inline]
 netlink_unicast+0x87c/0xa40 net/netlink/af_netlink.c:1333
 netlink_sendmsg+0x88d/0xb30 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2376
 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2430
 __sys_sendmsg net/socket.c:2459 [inline]
 __do_sys_sendmsg net/socket.c:2468 [inline]
 __se_sys_sendmsg net/socket.c:2466 [inline]
 __x64_sys_sendmsg+0x1e2/0x2a0 net/socket.c:2466
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Freed by task 11230:
 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
 kfree_skb_list+0x41/0x70 net/core/skbuff.c:722
 ip_do_fragment+0x1a78/0x2090 net/ipv4/ip_output.c:881
 ip_fragment+0x125/0x210 net/ipv4/ip_output.c:-1
 __ip_finish_output+0x4ce/0x720 net/ipv4/ip_output.c:313
 ip_finish_output+0x33/0x1f0 net/ipv4/ip_output.c:325
 NF_HOOK_COND include/linux/netfilter.h:288 [inline]
 ip_output+0x1e1/0x360 net/ipv4/ip_output.c:439
 dst_output include/net/dst.h:451 [inline]
 ip_local_out net/ipv4/ip_output.c:126 [inline]
 ip_send_skb net/ipv4/ip_output.c:1591 [inline]
 ip_push_pending_frames+0x2c3/0x540 net/ipv4/ip_output.c:1611
 raw_sendmsg+0xdd7/0x1270 net/ipv4/raw.c:676
 inet_sendmsg+0xa5/0xc0 net/ipv4/af_inet.c:830
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2376
 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2430
 __sys_sendmsg net/socket.c:2459 [inline]
 __do_sys_sendmsg net/socket.c:2468 [inline]
 __se_sys_sendmsg net/socket.c:2466 [inline]
 __x64_sys_sendmsg+0x1e2/0x2a0 net/socket.c:2466
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

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
 kvfree_call_rcu+0x10c/0x620 kernel/rcu/tree.c:3535
 drop_sysctl_table+0x2ef/0x410 fs/proc/proc_sysctl.c:1680
 unregister_sysctl_table+0x75/0x120 fs/proc/proc_sysctl.c:1718
 unregister_net_sysctl_table+0x15/0x20 net/sysctl_net.c:127
 __devinet_sysctl_unregister net/ipv4/devinet.c:2622 [inline]
 devinet_sysctl_unregister net/ipv4/devinet.c:2650 [inline]
 inetdev_destroy net/ipv4/devinet.c:326 [inline]
 inetdev_event+0x79d/0x1030 net/ipv4/devinet.c:1613
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0x90/0x100 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+0xf8b/0x1980 net/core/dev.c:10766
 __rtnl_newlink net/core/rtnetlink.c:3513 [inline]
 rtnl_newlink+0x1517/0x1640 net/core/rtnetlink.c:3530
 rtnetlink_rcv_msg+0x9db/0xb90 net/core/rtnetlink.c:5610
 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2485
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5628
 netlink_unicast_kernel net/netlink/af_netlink.c:1307 [inline]
 netlink_unicast+0x87c/0xa40 net/netlink/af_netlink.c:1333
 netlink_sendmsg+0x88d/0xb30 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2376
 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2430
 __sys_sendmsg net/socket.c:2459 [inline]
 __do_sys_sendmsg net/socket.c:2468 [inline]
 __se_sys_sendmsg net/socket.c:2466 [inline]
 __x64_sys_sendmsg+0x1e2/0x2a0 net/socket.c:2466
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

The buggy address belongs to the object at ffff8881009a3000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1120 bytes inside of
 2048-byte region [ffff8881009a3000, ffff8881009a3800)
The buggy address belongs to the page:
page:ffffea0004026800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1009a0
head:ffffea0004026800 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, ts 2014474945, 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+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:5349
 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]
 kmem_cache_alloc_trace+0x1b3/0x2e0 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]
 __alloc_disk_node+0x79/0x580 block/genhd.c:1727
 brd_alloc+0x144/0x3e0 drivers/block/brd.c:394
 brd_init+0x125/0x468 drivers/block/brd.c:517
 do_one_initcall+0x187/0x510 init/main.c:1197
 do_initcall_level+0x16f/0x2cf init/main.c:1270
 do_initcalls+0x50/0x92 init/main.c:1286
 do_basic_setup+0x88/0x8f init/main.c:1306
 kernel_init_freeable+0x287/0x3be init/main.c:1510
 kernel_init+0x11/0x1a0 init/main.c:1397
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8881009a3300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881009a3380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881009a3400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff8881009a3480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881009a3500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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