Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: KASAN: slab-use-after-free Write in hci_conn_drop ================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline] BUG: KASAN: slab-use-after-free in atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1383 [inline] BUG: KASAN: slab-use-after-free in hci_conn_drop+0x34/0x280 include/net/bluetooth/hci_core.h:1548 Write of size 4 at addr ffff88801ea58010 by task syz-executor.0/5537 CPU: 0 UID: 0 PID: 5537 Comm: syz-executor.0 Not tainted 6.12.0-rc1-syzkaller-g7ec462100ef9-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189 instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1383 [inline] hci_conn_drop+0x34/0x280 include/net/bluetooth/hci_core.h:1548 sco_conn_destruct+0x57/0x100 net/bluetooth/sco.c:166 sco_sock_destruct+0x43/0x90 net/bluetooth/sco.c:407 __sk_destruct+0x5a/0x5f0 net/core/sock.c:2259 sco_sock_release+0x25e/0x320 net/bluetooth/sco.c:1259 __sock_release net/socket.c:658 [inline] sock_close+0xbe/0x240 net/socket.c:1426 __fput+0x241/0x880 fs/file_table.c:431 __do_sys_close fs/open.c:1565 [inline] __se_sys_close fs/open.c:1550 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1550 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa71cc7cd5a Code: 48 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c 24 0c e8 03 7f 02 00 8b 7c 24 0c 89 c2 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 36 89 d7 89 44 24 0c e8 63 7f 02 00 8b 44 24 RSP: 002b:00007ffc91af2860 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00007fa71cc7cd5a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007fa71cdad980 R08: 0000001b2d160000 R09: 7fffffffffffffff R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000016f8e R13: ffffffffffffffff R14: 00007fa71c800000 R15: 0000000000016c4d </TASK> Allocated by task 5455: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:257 [inline] __kmalloc_cache_noprof+0x19c/0x2c0 mm/slub.c:4296 kmalloc_noprof include/linux/slab.h:878 [inline] kzalloc_noprof include/linux/slab.h:1014 [inline] __hci_conn_add+0x2f9/0x1850 net/bluetooth/hci_conn.c:932 hci_conn_add_unset net/bluetooth/hci_conn.c:1041 [inline] hci_connect_sco+0xd0/0x370 net/bluetooth/hci_conn.c:1689 sco_connect net/bluetooth/sco.c:279 [inline] sco_sock_connect+0x2fc/0x990 net/bluetooth/sco.c:596 __sys_connect_file net/socket.c:2066 [inline] __sys_connect+0x2d3/0x300 net/socket.c:2083 __do_sys_connect net/socket.c:2093 [inline] __se_sys_connect net/socket.c:2090 [inline] __x64_sys_connect+0x7a/0x90 net/socket.c:2090 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 4494: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:2343 [inline] slab_free mm/slub.c:4580 [inline] kfree+0x1a0/0x440 mm/slub.c:4728 device_release+0x9b/0x1c0 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x231/0x480 lib/kobject.c:737 hci_conn_cleanup net/bluetooth/hci_conn.c:174 [inline] hci_conn_del+0x8c4/0xc40 net/bluetooth/hci_conn.c:1160 hci_abort_conn_sync+0x583/0xde0 net/bluetooth/hci_sync.c:5586 hci_cmd_sync_work+0x22d/0x400 net/bluetooth/hci_sync.c:328 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Last potentially related work creation: kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:541 insert_work+0x3e/0x330 kernel/workqueue.c:2183 __queue_work+0xc8b/0xf50 kernel/workqueue.c:2339 queue_delayed_work_on+0x1ca/0x390 kernel/workqueue.c:2552 sco_conn_destruct+0x57/0x100 net/bluetooth/sco.c:166 sco_sock_destruct+0x43/0x90 net/bluetooth/sco.c:407 __sk_destruct+0x5a/0x5f0 net/core/sock.c:2259 sco_sock_release+0x25e/0x320 net/bluetooth/sco.c:1259 __sock_release net/socket.c:658 [inline] sock_close+0xbe/0x240 net/socket.c:1426 __fput+0x241/0x880 fs/file_table.c:431 task_work_run+0x251/0x310 kernel/task_work.c:228 get_signal+0x15e8/0x1740 kernel/signal.c:2690 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88801ea58000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 16 bytes inside of freed 8192-byte region [ffff88801ea58000, ffff88801ea5a000) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1ea58 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff888015442280 0000000000000000 dead000000000001 raw: 0000000000000000 0000000080020002 00000001f5000000 0000000000000000 head: 00fff00000000040 ffff888015442280 0000000000000000 dead000000000001 head: 0000000000000000 0000000080020002 00000001f5000000 0000000000000000 head: 00fff00000000003 ffffea00007a9601 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 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4772, tgid 4772 (dhcpcd-run-hook), ts 33884825404, free_ts 32631813811 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537 prep_new_page mm/page_alloc.c:1545 [inline] get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4733 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 alloc_slab_page+0x6a/0x120 mm/slub.c:2413 allocate_slab+0x5a/0x2f0 mm/slub.c:2579 new_slab mm/slub.c:2632 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3819 __slab_alloc+0x58/0xa0 mm/slub.c:3909 __slab_alloc_node mm/slub.c:3962 [inline] slab_alloc_node mm/slub.c:4123 [inline] __kmalloc_cache_noprof+0x1d5/0x2c0 mm/slub.c:4291 kmalloc_noprof include/linux/slab.h:878 [inline] kzalloc_noprof include/linux/slab.h:1014 [inline] tomoyo_print_bprm security/tomoyo/audit.c:26 [inline] tomoyo_init_log+0x11cd/0x2050 security/tomoyo/audit.c:264 tomoyo_supervisor+0x38a/0x11f0 security/tomoyo/common.c:2099 tomoyo_audit_env_log security/tomoyo/environ.c:36 [inline] tomoyo_env_perm+0x178/0x210 security/tomoyo/environ.c:63 tomoyo_environ security/tomoyo/domain.c:672 [inline] tomoyo_find_next_domain+0x146e/0x1d40 security/tomoyo/domain.c:881 tomoyo_bprm_check_security+0x114/0x180 security/tomoyo/hooks.h:76 security_bprm_check+0x86/0x250 security/security.c:1296 search_binary_handler fs/exec.c:1740 [inline] exec_binprm fs/exec.c:1794 [inline] bprm_execve+0xa56/0x1770 fs/exec.c:1845 page last free pid 4743 tgid 4743 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638 discard_slab mm/slub.c:2678 [inline] __put_partials+0xeb/0x130 mm/slub.c:3146 put_cpu_partial+0x17c/0x250 mm/slub.c:3221 __slab_free+0x2ea/0x3d0 mm/slub.c:4450 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4086 [inline] slab_alloc_node mm/slub.c:4135 [inline] __kmalloc_cache_noprof+0x132/0x2c0 mm/slub.c:4291 kmalloc_noprof include/linux/slab.h:878 [inline] tomoyo_print_header security/tomoyo/audit.c:156 [inline] tomoyo_init_log+0x1ca/0x2050 security/tomoyo/audit.c:255 tomoyo_supervisor+0x38a/0x11f0 security/tomoyo/common.c:2099 tomoyo_audit_path_log security/tomoyo/file.c:168 [inline] tomoyo_path_permission+0x243/0x360 security/tomoyo/file.c:587 tomoyo_path_perm+0x480/0x740 security/tomoyo/file.c:838 security_inode_getattr+0x130/0x330 security/security.c:2371 vfs_getattr+0x45/0x430 fs/stat.c:204 vfs_fstat fs/stat.c:229 [inline] vfs_fstatat+0xe4/0x190 fs/stat.c:338 __do_sys_newfstatat fs/stat.c:505 [inline] __se_sys_newfstatat fs/stat.c:499 [inline] __x64_sys_newfstatat+0x11d/0x1a0 fs/stat.c:499 Memory state around the buggy address: ffff88801ea57f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801ea57f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88801ea58000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801ea58080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801ea58100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Tested on: commit: 7ec46210 Merge tag 'pull-work.unaligned' of git://git... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=114d5527980000 kernel config: https://syzkaller.appspot.com/x/.config?x=d0ca089c3fc6b54e dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 patch: https://syzkaller.appspot.com/x/patch.diff?x=15355527980000