================================================================== BUG: KASAN: slab-use-after-free in force_devcd_write+0x317/0x340 drivers/bluetooth/hci_vhci.c:327 Read of size 8 at addr ffff8880275e3000 by task syz.1.3418/32172 CPU: 0 UID: 0 PID: 32172 Comm: syz.1.3418 Tainted: G U 6.14.0-syzkaller-03576-g1e1ba8d23dae #0 PREEMPT(full) Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xc3/0x670 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 force_devcd_write+0x317/0x340 drivers/bluetooth/hci_vhci.c:327 full_proxy_write+0x13c/0x200 fs/debugfs/file.c:398 vfs_write+0x25c/0x1180 fs/read_write.c:682 ksys_write+0x12a/0x240 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe13e58d169 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:00007fe13f354038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fe13e7a5fa0 RCX: 00007fe13e58d169 RDX: 000000000000000e RSI: 0000000000000000 RDI: 000000000000000a RBP: 00007fe13e60e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fe13e7a5fa0 R15: 00007fffd82ddb68 Allocated by task 31170: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kmalloc_noprof include/linux/slab.h:902 [inline] kzalloc_noprof include/linux/slab.h:1036 [inline] afs_alloc_call+0x51/0x640 fs/afs/rxrpc.c:144 afs_charge_preallocation+0xff/0x330 fs/afs/rxrpc.c:728 afs_open_socket+0x2b2/0x380 fs/afs/rxrpc.c:95 afs_net_init+0x746/0x9f0 fs/afs/main.c:115 ops_init+0x1df/0x5f0 net/core/net_namespace.c:138 setup_net+0x21e/0x850 net/core/net_namespace.c:362 copy_net_ns+0x2a6/0x5f0 net/core/net_namespace.c:516 create_new_namespaces+0x3ea/0xad0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:228 ksys_unshare+0x45b/0xa40 kernel/fork.c:3337 __do_sys_unshare kernel/fork.c:3408 [inline] __se_sys_unshare kernel/fork.c:3406 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3406 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 3593: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2376 [inline] slab_free mm/slub.c:4633 [inline] kfree+0x2b6/0x4d0 mm/slub.c:4832 afs_free_call+0x303/0x440 fs/afs/rxrpc.c:188 afs_put_call+0x188/0x1e0 fs/afs/rxrpc.c:210 rxrpc_discard_prealloc+0x67c/0x970 net/rxrpc/call_accept.c:224 rxrpc_listen+0x117/0x330 net/rxrpc/af_rxrpc.c:246 afs_close_socket+0x96/0x340 fs/afs/rxrpc.c:113 afs_net_exit+0x93/0x140 fs/afs/main.c:148 ops_exit_list+0xb0/0x180 net/core/net_namespace.c:172 cleanup_net+0x5c1/0xb30 net/core/net_namespace.c:652 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c1/0xef0 kernel/workqueue.c:3400 kthread+0x3a4/0x760 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff8880275e3000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 0 bytes inside of freed 1024-byte region [ffff8880275e3000, ffff8880275e3400) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880275e3000 pfn:0x275e0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88801b041dc0 ffffea00008df610 ffffea0000a56810 raw: ffff8880275e3000 000000000010000c 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801b041dc0 ffffea00008df610 ffffea0000a56810 head: ffff8880275e3000 000000000010000c 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea00009d7801 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 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 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 63, tgid 63 (kworker/u8:4), ts 13703885737, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1551 prep_new_page mm/page_alloc.c:1559 [inline] get_page_from_freelist+0x10c4/0x34c0 mm/page_alloc.c:3477 __alloc_frozen_pages_noprof+0x223/0x24d0 mm/page_alloc.c:4740 alloc_slab_page mm/slub.c:2448 [inline] allocate_slab mm/slub.c:2610 [inline] new_slab+0x94/0x330 mm/slub.c:2663 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3849 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3939 __slab_alloc_node mm/slub.c:4014 [inline] slab_alloc_node mm/slub.c:4175 [inline] __kmalloc_cache_node_noprof+0x100/0x420 mm/slub.c:4357 kmalloc_node_noprof include/linux/slab.h:925 [inline] blk_mq_alloc_hctx block/blk-mq.c:3945 [inline] blk_mq_alloc_and_init_hctx+0x639/0x11c0 block/blk-mq.c:4448 blk_mq_realloc_hw_ctxs+0x8f6/0xc00 block/blk-mq.c:4481 blk_mq_init_allocated_queue+0x3af/0x1230 block/blk-mq.c:4535 blk_mq_alloc_queue+0x1c2/0x290 block/blk-mq.c:4348 scsi_alloc_sdev+0x88f/0xd80 drivers/scsi/scsi_scan.c:338 scsi_probe_and_add_lun+0x76b/0xd80 drivers/scsi/scsi_scan.c:1209 __scsi_scan_target+0x1e8/0x580 drivers/scsi/scsi_scan.c:1774 scsi_scan_channel drivers/scsi/scsi_scan.c:1862 [inline] scsi_scan_channel+0x149/0x1e0 drivers/scsi/scsi_scan.c:1838 scsi_scan_host_selected+0x302/0x400 drivers/scsi/scsi_scan.c:1891 page_owner free stack trace missing Memory state around the buggy address: ffff8880275e2f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880275e2f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880275e3000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880275e3080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880275e3100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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