syzbot has found a reproducer for the following issue on: HEAD commit: 58390c8ce1bd Merge tag 'iommu-updates-v6.4' of git://git.k.. git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=1502fd68280000 kernel config: https://syzkaller.appspot.com/x/.config?x=d56ffc213bf6bf4a dashboard link: https://syzkaller.appspot.com/bug?extid=8bb72f86fc823817bc5d compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=121cf70c280000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12ace9d8280000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/64e93dba0330/disk-58390c8c.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/2b7f3c1154f1/vmlinux-58390c8c.xz kernel image: https://storage.googleapis.com/syzbot-assets/4ad00371a063/bzImage-58390c8c.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+8bb72f86fc823817bc5d@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: slab-use-after-free in hci_conn_hash_flush+0x244/0x270 net/bluetooth/hci_conn.c:2470 Read of size 8 at addr ffff88807df46000 by task syz-executor183/4997 CPU: 0 PID: 4997 Comm: syz-executor183 Not tainted 6.3.0-syzkaller-12049-g58390c8ce1bd #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:351 print_report mm/kasan/report.c:462 [inline] kasan_report+0x11c/0x130 mm/kasan/report.c:572 hci_conn_hash_flush+0x244/0x270 net/bluetooth/hci_conn.c:2470 hci_dev_close_sync+0x5fb/0x1200 net/bluetooth/hci_sync.c:4941 hci_dev_do_close+0x31/0x70 net/bluetooth/hci_core.c:554 hci_unregister_dev+0x1ce/0x580 net/bluetooth/hci_core.c:2703 vhci_release+0x80/0xf0 drivers/bluetooth/hci_vhci.c:669 __fput+0x27c/0xa90 fs/file_table.c:321 task_work_run+0x16f/0x270 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xad3/0x2960 kernel/exit.c:871 do_group_exit+0xd4/0x2a0 kernel/exit.c:1021 __do_sys_exit_group kernel/exit.c:1032 [inline] __se_sys_exit_group kernel/exit.c:1030 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1030 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f5c483ecbe9 Code: Unable to access opcode bytes at 0x7f5c483ecbbf. RSP: 002b:00007ffcf6d71ce8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f5c484773b0 RCX: 00007f5c483ecbe9 RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000001 RBP: 0000000000000001 R08: ffffffffffffffb8 R09: 0000000000000010 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5c484773b0 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001 </TASK> Allocated by task 5002: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] ____kasan_kmalloc mm/kasan/common.c:333 [inline] __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:559 [inline] kzalloc include/linux/slab.h:680 [inline] hci_conn_add+0xb8/0x16b0 net/bluetooth/hci_conn.c:986 hci_connect_sco+0x3c7/0x1050 net/bluetooth/hci_conn.c:1663 sco_connect net/bluetooth/sco.c:264 [inline] sco_sock_connect+0x2d7/0xae0 net/bluetooth/sco.c:610 __sys_connect_file+0x153/0x1a0 net/socket.c:2003 __sys_connect+0x165/0x1a0 net/socket.c:2020 __do_sys_connect net/socket.c:2030 [inline] __se_sys_connect net/socket.c:2027 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:2027 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 4997: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:521 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:162 [inline] slab_free_hook mm/slub.c:1781 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1807 slab_free mm/slub.c:3786 [inline] __kmem_cache_free+0xaf/0x2d0 mm/slub.c:3799 device_release+0xa3/0x240 drivers/base/core.c:2484 kobject_cleanup lib/kobject.c:683 [inline] kobject_release lib/kobject.c:714 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1c2/0x4d0 lib/kobject.c:731 put_device+0x1f/0x30 drivers/base/core.c:3733 hci_conn_del+0x1e5/0x950 net/bluetooth/hci_conn.c:1162 hci_conn_unlink+0x2ce/0x460 net/bluetooth/hci_conn.c:1109 hci_conn_unlink+0x362/0x460 net/bluetooth/hci_conn.c:1087 hci_conn_hash_flush+0x19b/0x270 net/bluetooth/hci_conn.c:2479 hci_dev_close_sync+0x5fb/0x1200 net/bluetooth/hci_sync.c:4941 hci_dev_do_close+0x31/0x70 net/bluetooth/hci_core.c:554 hci_unregister_dev+0x1ce/0x580 net/bluetooth/hci_core.c:2703 vhci_release+0x80/0xf0 drivers/bluetooth/hci_vhci.c:669 __fput+0x27c/0xa90 fs/file_table.c:321 task_work_run+0x16f/0x270 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xad3/0x2960 kernel/exit.c:871 do_group_exit+0xd4/0x2a0 kernel/exit.c:1021 __do_sys_exit_group kernel/exit.c:1032 [inline] __se_sys_exit_group kernel/exit.c:1030 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1030 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff88807df46000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 0 bytes inside of freed 4096-byte region [ffff88807df46000, ffff88807df47000) The buggy address belongs to the physical page: page:ffffea0001f7d000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7df40 head:ffffea0001f7d000 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000010200 ffff888012442140 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000040004 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 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5002, tgid 4997 (syz-executor183), ts 41448885910, free_ts 34737312749 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2db/0x350 mm/page_alloc.c:1722 prep_new_page mm/page_alloc.c:1729 [inline] get_page_from_freelist+0xf41/0x2c00 mm/page_alloc.c:3493 __alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:4759 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2277 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x25f/0x390 mm/slub.c:1998 new_slab mm/slub.c:2051 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3192 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3291 __slab_alloc_node mm/slub.c:3344 [inline] slab_alloc_node mm/slub.c:3441 [inline] __kmem_cache_alloc_node+0x136/0x320 mm/slub.c:3490 __do_kmalloc_node mm/slab_common.c:965 [inline] __kmalloc+0x4e/0x190 mm/slab_common.c:979 kmalloc include/linux/slab.h:563 [inline] tomoyo_realpath_from_path+0xc3/0x600 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x29a/0x3a0 security/tomoyo/file.c:771 tomoyo_file_open security/tomoyo/tomoyo.c:332 [inline] tomoyo_file_open+0xa1/0xc0 security/tomoyo/tomoyo.c:327 security_file_open+0x49/0xb0 security/security.c:2797 do_dentry_open+0x575/0x13f0 fs/open.c:907 do_open fs/namei.c:3636 [inline] path_openat+0x1baa/0x2750 fs/namei.c:3791 do_filp_open+0x1ba/0x410 fs/namei.c:3818 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1302 [inline] free_unref_page_prepare+0x62e/0xcb0 mm/page_alloc.c:2555 free_unref_page+0x33/0x370 mm/page_alloc.c:2650 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2636 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x195/0x220 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x63/0x90 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:186 [inline] slab_post_alloc_hook mm/slab.h:711 [inline] slab_alloc_node mm/slub.c:3451 [inline] slab_alloc mm/slub.c:3459 [inline] __kmem_cache_alloc_lru mm/slub.c:3466 [inline] kmem_cache_alloc+0x17c/0x3b0 mm/slub.c:3475 ptlock_alloc+0x21/0x70 mm/memory.c:5942 ptlock_init include/linux/mm.h:2755 [inline] pgtable_pte_page_ctor include/linux/mm.h:2776 [inline] __pte_alloc_one include/asm-generic/pgalloc.h:66 [inline] pte_alloc_one+0x6c/0x230 arch/x86/mm/pgtable.c:33 __pte_alloc+0x6d/0x260 mm/memory.c:439 do_anonymous_page mm/memory.c:4053 [inline] do_pte_missing mm/memory.c:3645 [inline] handle_pte_fault mm/memory.c:4947 [inline] __handle_mm_fault+0x412e/0x41c0 mm/memory.c:5089 handle_mm_fault+0x2af/0x9f0 mm/memory.c:5243 do_user_addr_fault+0x2ca/0x1210 arch/x86/mm/fault.c:1349 handle_page_fault arch/x86/mm/fault.c:1534 [inline] exc_page_fault+0x98/0x170 arch/x86/mm/fault.c:1590 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570 Memory state around the buggy address: ffff88807df45f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807df45f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88807df46000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807df46080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807df46100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing.