Hello, syzbot found the following issue on: HEAD commit: 243f750a2df0 Merge tag 'gpio-fixes-for-v6.13-rc3' of git:/.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=149edbe8580000 kernel config: https://syzkaller.appspot.com/x/.config?x=99a5586995ec03b2 dashboard link: https://syzkaller.appspot.com/bug?extid=4c5f0c6f8cc60159bdbf compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 userspace arch: i386 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-243f750a.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/e3ec11e872fc/vmlinux-243f750a.xz kernel image: https://storage.googleapis.com/syzbot-assets/d9df37410c95/bzImage-243f750a.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+4c5f0c6f8cc60159bdbf@xxxxxxxxxxxxxxxxxxxxxxxxx ========================= WARNING: held lock freed! 6.13.0-rc2-syzkaller-00192-g243f750a2df0 #0 Not tainted ------------------------- syz.0.39/6085 is freeing memory ffff88806780b000-ffff88806780b7ff, with a lock still held there! ffff88806780b258 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1617 [inline] ffff88806780b258 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0}, at: bt_accept_dequeue+0x249/0x600 net/bluetooth/af_bluetooth.c:276 2 locks held by syz.0.39/6085: #0: ffff888066585008 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline] #0: ffff888066585008 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release+0x86/0x270 net/socket.c:639 #1: ffff88806780b258 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1617 [inline] #1: ffff88806780b258 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0}, at: bt_accept_dequeue+0x249/0x600 net/bluetooth/af_bluetooth.c:276 stack backtrace: CPU: 3 UID: 0 PID: 6085 Comm: syz.0.39 Not tainted 6.13.0-rc2-syzkaller-00192-g243f750a2df0 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_freed_lock_bug kernel/locking/lockdep.c:6662 [inline] debug_check_no_locks_freed+0x208/0x2b0 kernel/locking/lockdep.c:6697 slab_free_hook mm/slub.c:2281 [inline] slab_free mm/slub.c:4613 [inline] kfree+0xe5/0x4b0 mm/slub.c:4761 sk_prot_free net/core/sock.c:2201 [inline] __sk_destruct+0x5eb/0x720 net/core/sock.c:2293 sk_destruct+0xc2/0xf0 net/core/sock.c:2308 __sk_free+0xf4/0x3e0 net/core/sock.c:2319 sk_free+0x6a/0x90 net/core/sock.c:2330 sock_put include/net/sock.h:1904 [inline] bt_accept_unlink+0x245/0x2e0 net/bluetooth/af_bluetooth.c:259 bt_accept_dequeue+0x517/0x600 net/bluetooth/af_bluetooth.c:305 l2cap_sock_cleanup_listen+0x5c/0x2a0 net/bluetooth/l2cap_sock.c:1439 l2cap_sock_release+0x5c/0x210 net/bluetooth/l2cap_sock.c:1413 __sock_release+0xb0/0x270 net/socket.c:640 sock_close+0x1c/0x30 net/socket.c:1408 __fput+0x3f8/0xb60 fs/file_table.c:450 task_work_run+0x14e/0x250 kernel/task_work.c:239 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218 __do_fast_syscall_32+0x80/0x120 arch/x86/entry/common.c:389 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7ff5579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000ff8596dc EFLAGS: 00000202 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 000000000000001e RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> ================================================================== BUG: KASAN: slab-use-after-free in debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline] BUG: KASAN: slab-use-after-free in do_raw_spin_lock+0x271/0x2c0 kernel/locking/spinlock_debug.c:115 Read of size 4 at addr ffff88806780b1c4 by task syz.0.39/6085 CPU: 3 UID: 0 PID: 6085 Comm: syz.0.39 Not tainted 6.13.0-rc2-syzkaller-00192-g243f750a2df0 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <TASK> __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:378 [inline] print_report+0xc3/0x620 mm/kasan/report.c:489 kasan_report+0xd9/0x110 mm/kasan/report.c:602 debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline] do_raw_spin_lock+0x271/0x2c0 kernel/locking/spinlock_debug.c:115 spin_lock_bh include/linux/spinlock.h:356 [inline] release_sock+0x21/0x220 net/core/sock.c:3635 bt_accept_dequeue+0x505/0x600 net/bluetooth/af_bluetooth.c:309 l2cap_sock_cleanup_listen+0x5c/0x2a0 net/bluetooth/l2cap_sock.c:1439 l2cap_sock_release+0x5c/0x210 net/bluetooth/l2cap_sock.c:1413 __sock_release+0xb0/0x270 net/socket.c:640 sock_close+0x1c/0x30 net/socket.c:1408 __fput+0x3f8/0xb60 fs/file_table.c:450 task_work_run+0x14e/0x250 kernel/task_work.c:239 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218 __do_fast_syscall_32+0x80/0x120 arch/x86/entry/common.c:389 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7ff5579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000ff8596dc EFLAGS: 00000202 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 000000000000001e RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> Allocated by task 5953: 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 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4298 [inline] __kmalloc_noprof+0x21a/0x4f0 mm/slub.c:4310 kmalloc_noprof include/linux/slab.h:905 [inline] sk_prot_alloc+0x1a8/0x2a0 net/core/sock.c:2165 sk_alloc+0x36/0xb90 net/core/sock.c:2218 bt_sock_alloc+0x3b/0x3a0 net/bluetooth/af_bluetooth.c:148 l2cap_sock_alloc.constprop.0+0x33/0x1c0 net/bluetooth/l2cap_sock.c:1879 l2cap_sock_new_connection_cb+0x101/0x240 net/bluetooth/l2cap_sock.c:1470 l2cap_connect_cfm+0x85f/0xf10 net/bluetooth/l2cap_core.c:7263 hci_connect_cfm include/net/bluetooth/hci_core.h:2057 [inline] hci_remote_features_evt+0x5aa/0xa30 net/bluetooth/hci_event.c:3726 hci_event_func net/bluetooth/hci_event.c:7473 [inline] hci_event_packet+0x9eb/0x1190 net/bluetooth/hci_event.c:7525 hci_rx_work+0x2c5/0x16b0 net/bluetooth/hci_core.c:4035 process_one_work+0x958/0x1b30 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Freed by task 6085: 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:582 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:2353 [inline] slab_free mm/slub.c:4613 [inline] kfree+0x14f/0x4b0 mm/slub.c:4761 sk_prot_free net/core/sock.c:2201 [inline] __sk_destruct+0x5eb/0x720 net/core/sock.c:2293 sk_destruct+0xc2/0xf0 net/core/sock.c:2308 __sk_free+0xf4/0x3e0 net/core/sock.c:2319 sk_free+0x6a/0x90 net/core/sock.c:2330 sock_put include/net/sock.h:1904 [inline] bt_accept_unlink+0x245/0x2e0 net/bluetooth/af_bluetooth.c:259 bt_accept_dequeue+0x517/0x600 net/bluetooth/af_bluetooth.c:305 l2cap_sock_cleanup_listen+0x5c/0x2a0 net/bluetooth/l2cap_sock.c:1439 l2cap_sock_release+0x5c/0x210 net/bluetooth/l2cap_sock.c:1413 __sock_release+0xb0/0x270 net/socket.c:640 sock_close+0x1c/0x30 net/socket.c:1408 __fput+0x3f8/0xb60 fs/file_table.c:450 task_work_run+0x14e/0x250 kernel/task_work.c:239 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218 __do_fast_syscall_32+0x80/0x120 arch/x86/entry/common.c:389 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e The buggy address belongs to the object at ffff88806780b000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 452 bytes inside of freed 2048-byte region [ffff88806780b000, ffff88806780b800) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x67808 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 04fff00000000040 ffff88801ac42f00 ffffea00019a8600 dead000000000002 raw: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000 head: 04fff00000000040 ffff88801ac42f00 ffffea00019a8600 dead000000000002 head: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000 head: 04fff00000000003 ffffea00019e0201 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5945, tgid 5945 (syz-executor), ts 45957452176, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1556 prep_new_page mm/page_alloc.c:1564 [inline] get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3474 __alloc_pages_noprof+0x223/0x25b0 mm/page_alloc.c:4751 alloc_pages_mpol_noprof+0x2c9/0x610 mm/mempolicy.c:2269 alloc_slab_page mm/slub.c:2423 [inline] allocate_slab mm/slub.c:2589 [inline] new_slab+0x2c9/0x410 mm/slub.c:2642 ___slab_alloc+0xce2/0x1650 mm/slub.c:3830 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3920 __slab_alloc_node mm/slub.c:3995 [inline] slab_alloc_node mm/slub.c:4156 [inline] __kmalloc_cache_noprof+0xf6/0x420 mm/slub.c:4324 kmalloc_noprof include/linux/slab.h:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] nsim_bus_dev_new drivers/net/netdevsim/bus.c:425 [inline] new_device_store+0x207/0x730 drivers/net/netdevsim/bus.c:173 bus_attr_store+0x71/0xb0 drivers/base/bus.c:172 sysfs_kf_write+0x117/0x170 fs/sysfs/file.c:139 kernfs_fop_write_iter+0x33d/0x500 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:586 [inline] vfs_write+0x5ae/0x1150 fs/read_write.c:679 ksys_write+0x12b/0x250 fs/read_write.c:731 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 page_owner free stack trace missing Memory state around the buggy address: ffff88806780b080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806780b100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88806780b180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88806780b200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806780b280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup