================================================================== 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 ffff88810ddc8460 by task syz.0.3375/13420 CPU: 1 PID: 13420 Comm: syz.0.3375 Tainted: G W 5.10.234-syzkaller-00023-g3f5f2283d684 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 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: 0033:0x7fa089275169 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:00007fa0878df038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fa08948dfa0 RCX: 00007fa089275169 RDX: 0000000000000000 RSI: 0000400000000040 RDI: ffffffffffffff9c RBP: 00007fa0892f62a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa08948dfa0 R15: 00007fff6665d1c8 Allocated by task 13222: 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_node include/linux/slab.h:418 [inline] kmalloc_node include/linux/slab.h:575 [inline] kvmalloc_node+0x82/0x130 mm/util.c:612 kvmalloc include/linux/mm.h:822 [inline] kvmalloc_array include/linux/mm.h:840 [inline] __ptr_ring_init_queue_alloc include/linux/ptr_ring.h:471 [inline] ptr_ring_init include/linux/ptr_ring.h:489 [inline] skb_array_init include/linux/skb_array.h:182 [inline] pfifo_fast_init+0x25e/0x7a0 net/sched/sch_generic.c:779 qdisc_create_dflt+0x138/0x3d0 net/sched/sch_generic.c:931 mq_init+0x2c8/0x6b0 net/sched/sch_mq.c:90 qdisc_create_dflt+0x138/0x3d0 net/sched/sch_generic.c:931 attach_default_qdiscs net/sched/sch_generic.c:1110 [inline] dev_activate+0x123/0x1310 net/sched/sch_generic.c:1164 __dev_open+0x3bf/0x4e0 net/core/dev.c:1551 __dev_change_flags+0x1db/0x6e0 net/core/dev.c:8533 dev_change_flags+0x8c/0x1a0 net/core/dev.c:8604 dev_ifsioc+0x115/0xae0 net/core/dev_ioctl.c:230 dev_ioctl+0x526/0xb40 net/core/dev_ioctl.c:481 sock_do_ioctl+0x295/0x3a0 net/socket.c:1090 sock_ioctl+0x4a6/0x760 net/socket.c:1207 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0x114/0x190 fs/ioctl.c:739 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:739 do_syscall_64+0x34/0x70 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 13222: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x121/0x160 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+0xc0/0x190 mm/slub.c:1621 slab_free mm/slub.c:3203 [inline] kfree+0xc3/0x270 mm/slub.c:4191 kvfree+0x35/0x40 mm/util.c:647 ptr_ring_cleanup include/linux/ptr_ring.h:671 [inline] pfifo_fast_destroy+0x86/0xd0 net/sched/sch_generic.c:805 qdisc_destroy+0x9d/0x260 net/sched/sch_generic.c:999 qdisc_put net/sched/sch_generic.c:1018 [inline] shutdown_scheduler_queue net/sched/sch_generic.c:1071 [inline] netdev_for_each_tx_queue include/linux/netdevice.h:2321 [inline] dev_shutdown+0x192/0x560 net/sched/sch_generic.c:1378 unregister_netdevice_many+0x98c/0x17d0 net/core/dev.c:10759 unregister_netdevice_queue+0x2e6/0x350 net/core/dev.c:10700 unregister_netdevice include/linux/netdevice.h:2931 [inline] __tun_detach+0xd14/0x1510 drivers/net/tun.c:697 tun_detach drivers/net/tun.c:713 [inline] tun_chr_close+0x92/0x140 drivers/net/tun.c:3486 __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 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0xc83/0x2a50 kernel/exit.c:863 do_group_exit+0x141/0x310 kernel/exit.c:985 get_signal+0x10a0/0x1410 kernel/signal.c:2793 arch_do_signal_or_restart+0xbd/0x17c0 arch/x86/kernel/signal.c:805 handle_signal_work kernel/entry/common.c:145 [inline] exit_to_user_mode_loop+0x9b/0xd0 kernel/entry/common.c:169 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 ffff88810ddc8000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 1120 bytes inside of 8192-byte region [ffff88810ddc8000, ffff88810ddca000) The buggy address belongs to the page: page:ffffea0004377200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10ddc8 head:ffffea0004377200 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100042a80 raw: 0000000000000000 0000000000020002 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 13222, ts 590905324539, free_ts 582804901317 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+0x204/0x330 mm/slub.c:4029 __kmalloc_node include/linux/slab.h:418 [inline] kmalloc_node include/linux/slab.h:575 [inline] kvmalloc_node+0x82/0x130 mm/util.c:612 kvmalloc include/linux/mm.h:822 [inline] kvmalloc_array include/linux/mm.h:840 [inline] __ptr_ring_init_queue_alloc include/linux/ptr_ring.h:471 [inline] ptr_ring_init include/linux/ptr_ring.h:489 [inline] skb_array_init include/linux/skb_array.h:182 [inline] pfifo_fast_init+0x110/0x7a0 net/sched/sch_generic.c:779 qdisc_create_dflt+0x138/0x3d0 net/sched/sch_generic.c:931 mq_init+0x2c8/0x6b0 net/sched/sch_mq.c:90 qdisc_create_dflt+0x138/0x3d0 net/sched/sch_generic.c:931 attach_default_qdiscs net/sched/sch_generic.c:1110 [inline] dev_activate+0x123/0x1310 net/sched/sch_generic.c:1164 __dev_open+0x3bf/0x4e0 net/core/dev.c:1551 __dev_change_flags+0x1db/0x6e0 net/core/dev.c:8533 dev_change_flags+0x8c/0x1a0 net/core/dev.c:8604 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_pcp_prepare mm/page_alloc.c:1421 [inline] free_unref_page_prepare+0x2ae/0x2d0 mm/page_alloc.c:3336 free_unref_page mm/page_alloc.c:3391 [inline] free_the_page+0x9e/0x370 mm/page_alloc.c:5407 __free_pages+0x67/0xc0 mm/page_alloc.c:5418 bpf_ringbuf_free kernel/bpf/ringbuf.c:214 [inline] ringbuf_map_free+0xbe/0x120 kernel/bpf/ringbuf.c:223 bpf_map_free_deferred+0xb3/0x110 kernel/bpf/syscall.c:486 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 Memory state around the buggy address: ffff88810ddc8300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88810ddc8380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88810ddc8400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88810ddc8480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88810ddc8500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================