Re: [PATCH] Bluetooth: Use lock_sock() when acquiring lock in sco_conn_del
On 10/16/20 12:10 PM, Hillf Danton wrote:
On Fri, 16 Oct 2020 11:15:27 +0800 Yanfei Xu wrote:
On 10/14/20 8:31 PM, Hillf Danton wrote:
On Wed, 14 Oct 2020 15:17:31 +0800
From: Yanfei Xu
Locking slock-AF_BLUETOOTH-BTPROTO_SCO may happen in process context or
BH context. If in process context, we should use lock_sock(). As blow
warning, sco_conn_del() is called in process context, so let's use
lock_sock() instead of bh_lock_sock().
Sounds opposite because blocking BH in BH context provides no extra
protection while it makes sense in the less critical context particularly
wrt sock lock.
WARNING: inconsistent lock state
5.9.0-rc4-syzkaller #0 Not tainted
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
syz-executor675/31233 [HC0[0]:SC0[0]:HE1:SE1] takes:
8880a75c50a0 (slock-AF_BLUETOOTH-BTPROTO_SCO){+.?.}-{2:2}, at:
spin_lock include/linux/spinlock.h:354 [inline]
8880a75c50a0 (slock-AF_BLUETOOTH-BTPROTO_SCO){+.?.}-{2:2}, at:
sco_conn_del+0x128/0x270 net/bluetooth/sco.c:176
{IN-SOFTIRQ-W} state was registered at:
lock_acquire+0x1f3/0xae0 kernel/locking/lockdep.c:5006
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
spin_lock include/linux/spinlock.h:354 [inline]
sco_sock_timeout+0x24/0x140 net/bluetooth/sco.c:83
call_timer_fn+0x1ac/0x760 kernel/time/timer.c:1413
expire_timers kernel/time/timer.c:1458 [inline]
__run_timers.part.0+0x67c/0xaa0 kernel/time/timer.c:1755
__run_timers kernel/time/timer.c:1736 [inline]
run_timer_softirq+0xae/0x1a0 kernel/time/timer.c:1768
__do_softirq+0x1f7/0xa91 kernel/softirq.c:298
asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706
__run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
do_softirq_own_stack+0x9d/0xd0 arch/x86/kernel/irq_64.c:77
invoke_softirq kernel/softirq.c:393 [inline]
__irq_exit_rcu kernel/softirq.c:423 [inline]
irq_exit_rcu+0x235/0x280 kernel/softirq.c:435
sysvec_apic_timer_interrupt+0x51/0xf0 arch/x86/kernel/apic/apic.c:1091
asm_sysvec_apic_timer_interrupt+0x12/0x20
arch/x86/include/asm/idtentry.h:581
unwind_next_frame+0x139a/0x1f90 arch/x86/kernel/unwind_orc.c:607
arch_stack_walk+0x81/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
kasan_set_track mm/kasan/common.c:56 [inline]
__kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
slab_post_alloc_hook mm/slab.h:518 [inline]
slab_alloc mm/slab.c:3312 [inline]
kmem_cache_alloc+0x13a/0x3a0 mm/slab.c:3482
__d_alloc+0x2a/0x950 fs/dcache.c:1709
d_alloc+0x4a/0x230 fs/dcache.c:1788
d_alloc_parallel+0xe9/0x18e0 fs/dcache.c:2540
lookup_open.isra.0+0x9ac/0x1350 fs/namei.c:3030
open_last_lookups fs/namei.c:3177 [inline]
path_openat+0x96d/0x2730 fs/namei.c:3365
do_filp_open+0x17e/0x3c0 fs/namei.c:3395
do_sys_openat2+0x16d/0x420 fs/open.c:1168
do_sys_open fs/open.c:1184 [inline]
__do_sys_open fs/open.c:1192 [inline]
__se_sys_open fs/open.c:1188 [inline]
__x64_sys_open+0x119/0x1c0 fs/open.c:1188
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
irq event stamp: 853
hardirqs last enabled at (853): []
__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline]
hardirqs last enabled at (853): []
_raw_spin_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:199
hardirqs last disabled at (852): []
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:126 [inline]
hardirqs last disabled at (852): []
_raw_spin_lock_irq+0xa4/0xd0 kernel/locking/spinlock.c:167
softirqs last enabled at (0): []
copy_process+0x1a99/0x6920 kernel/fork.c:2018
softirqs last disabled at (0): [<>] 0x0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
lock(slock-AF_BLUETOOTH-BTPROTO_SCO);
lock(slock-AF_BLUETOOTH-BTPROTO_SCO);
*** DEADLOCK ***
3 locks held by syz-executor675/31233:
#0: 88809f104f40 (>req_lock){+.+.}-{3:3}, at:
hci_dev_do_close+0xf5/0x1080 net/bluetooth/hci_core.c:1720
#1: 88809f104078 (>lock){+.+.}-{3:3}, at:
hci_dev_do_close+0x253/0x1080 net/bluetooth/hci_core.c:1757
#2: 8a9188c8 (hci_cb_list_lock){+.+.}-{3:3}, at:
hci_disconn_cfm include/net/bluetooth/hci_core.h:1435 [inline]
#2: 8a9188c8 (hci_cb_list_lock){+.+.}-{3:3}, at:
hci_conn_hash_flush+0xc7/0x220 net/bluetooth/hci_conn.c:1557
stack backtrace:
CPU: 1 PID: 31233 Comm: syz-executor675 Not tainted 5.9.0-rc4-syzkaller
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x198/0x1fd lib/dump_stack.c:118
Re: [PATCH] Bluetooth: Use lock_sock() when acquiring lock in sco_conn_del
On 10/14/20 8:31 PM, Hillf Danton wrote:
On Wed, 14 Oct 2020 15:17:31 +0800
From: Yanfei Xu
Locking slock-AF_BLUETOOTH-BTPROTO_SCO may happen in process context or
BH context. If in process context, we should use lock_sock(). As blow
warning, sco_conn_del() is called in process context, so let's use
lock_sock() instead of bh_lock_sock().
Sounds opposite because blocking BH in BH context provides no extra
protection while it makes sense in the less critical context particularly
wrt sock lock.
WARNING: inconsistent lock state
5.9.0-rc4-syzkaller #0 Not tainted
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
syz-executor675/31233 [HC0[0]:SC0[0]:HE1:SE1] takes:
8880a75c50a0 (slock-AF_BLUETOOTH-BTPROTO_SCO){+.?.}-{2:2}, at:
spin_lock include/linux/spinlock.h:354 [inline]
8880a75c50a0 (slock-AF_BLUETOOTH-BTPROTO_SCO){+.?.}-{2:2}, at:
sco_conn_del+0x128/0x270 net/bluetooth/sco.c:176
{IN-SOFTIRQ-W} state was registered at:
lock_acquire+0x1f3/0xae0 kernel/locking/lockdep.c:5006
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
spin_lock include/linux/spinlock.h:354 [inline]
sco_sock_timeout+0x24/0x140 net/bluetooth/sco.c:83
call_timer_fn+0x1ac/0x760 kernel/time/timer.c:1413
expire_timers kernel/time/timer.c:1458 [inline]
__run_timers.part.0+0x67c/0xaa0 kernel/time/timer.c:1755
__run_timers kernel/time/timer.c:1736 [inline]
run_timer_softirq+0xae/0x1a0 kernel/time/timer.c:1768
__do_softirq+0x1f7/0xa91 kernel/softirq.c:298
asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706
__run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
do_softirq_own_stack+0x9d/0xd0 arch/x86/kernel/irq_64.c:77
invoke_softirq kernel/softirq.c:393 [inline]
__irq_exit_rcu kernel/softirq.c:423 [inline]
irq_exit_rcu+0x235/0x280 kernel/softirq.c:435
sysvec_apic_timer_interrupt+0x51/0xf0 arch/x86/kernel/apic/apic.c:1091
asm_sysvec_apic_timer_interrupt+0x12/0x20
arch/x86/include/asm/idtentry.h:581
unwind_next_frame+0x139a/0x1f90 arch/x86/kernel/unwind_orc.c:607
arch_stack_walk+0x81/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
kasan_set_track mm/kasan/common.c:56 [inline]
__kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
slab_post_alloc_hook mm/slab.h:518 [inline]
slab_alloc mm/slab.c:3312 [inline]
kmem_cache_alloc+0x13a/0x3a0 mm/slab.c:3482
__d_alloc+0x2a/0x950 fs/dcache.c:1709
d_alloc+0x4a/0x230 fs/dcache.c:1788
d_alloc_parallel+0xe9/0x18e0 fs/dcache.c:2540
lookup_open.isra.0+0x9ac/0x1350 fs/namei.c:3030
open_last_lookups fs/namei.c:3177 [inline]
path_openat+0x96d/0x2730 fs/namei.c:3365
do_filp_open+0x17e/0x3c0 fs/namei.c:3395
do_sys_openat2+0x16d/0x420 fs/open.c:1168
do_sys_open fs/open.c:1184 [inline]
__do_sys_open fs/open.c:1192 [inline]
__se_sys_open fs/open.c:1188 [inline]
__x64_sys_open+0x119/0x1c0 fs/open.c:1188
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
irq event stamp: 853
hardirqs last enabled at (853): []
__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline]
hardirqs last enabled at (853): []
_raw_spin_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:199
hardirqs last disabled at (852): []
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:126 [inline]
hardirqs last disabled at (852): []
_raw_spin_lock_irq+0xa4/0xd0 kernel/locking/spinlock.c:167
softirqs last enabled at (0): []
copy_process+0x1a99/0x6920 kernel/fork.c:2018
softirqs last disabled at (0): [<>] 0x0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
lock(slock-AF_BLUETOOTH-BTPROTO_SCO);
lock(slock-AF_BLUETOOTH-BTPROTO_SCO);
*** DEADLOCK ***
3 locks held by syz-executor675/31233:
#0: 88809f104f40 (>req_lock){+.+.}-{3:3}, at:
hci_dev_do_close+0xf5/0x1080 net/bluetooth/hci_core.c:1720
#1: 88809f104078 (>lock){+.+.}-{3:3}, at:
hci_dev_do_close+0x253/0x1080 net/bluetooth/hci_core.c:1757
#2: 8a9188c8 (hci_cb_list_lock){+.+.}-{3:3}, at:
hci_disconn_cfm include/net/bluetooth/hci_core.h:1435 [inline]
#2: 8a9188c8 (hci_cb_list_lock){+.+.}-{3:3}, at:
hci_conn_hash_flush+0xc7/0x220 net/bluetooth/hci_conn.c:1557
stack backtrace:
CPU: 1 PID: 31233 Comm: syz-executor675 Not tainted 5.9.0-rc4-syzkaller
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x198/0x1fd lib/dump_stack.c:118
print_usage_bug kernel/locking/lockdep.c:4020 [inline]
valid_state kernel/locking/lockdep.c:3361 [inline]
mark_lock_irq kernel/locking/lockdep.c:3560
[PATCH] Bluetooth: Use lock_sock() when acquiring lock in sco_conn_del
From: Yanfei Xu
Locking slock-AF_BLUETOOTH-BTPROTO_SCO may happen in process context or
BH context. If in process context, we should use lock_sock(). As blow
warning, sco_conn_del() is called in process context, so let's use
lock_sock() instead of bh_lock_sock().
WARNING: inconsistent lock state
5.9.0-rc4-syzkaller #0 Not tainted
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
syz-executor675/31233 [HC0[0]:SC0[0]:HE1:SE1] takes:
8880a75c50a0 (slock-AF_BLUETOOTH-BTPROTO_SCO){+.?.}-{2:2}, at:
spin_lock include/linux/spinlock.h:354 [inline]
8880a75c50a0 (slock-AF_BLUETOOTH-BTPROTO_SCO){+.?.}-{2:2}, at:
sco_conn_del+0x128/0x270 net/bluetooth/sco.c:176
{IN-SOFTIRQ-W} state was registered at:
lock_acquire+0x1f3/0xae0 kernel/locking/lockdep.c:5006
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
spin_lock include/linux/spinlock.h:354 [inline]
sco_sock_timeout+0x24/0x140 net/bluetooth/sco.c:83
call_timer_fn+0x1ac/0x760 kernel/time/timer.c:1413
expire_timers kernel/time/timer.c:1458 [inline]
__run_timers.part.0+0x67c/0xaa0 kernel/time/timer.c:1755
__run_timers kernel/time/timer.c:1736 [inline]
run_timer_softirq+0xae/0x1a0 kernel/time/timer.c:1768
__do_softirq+0x1f7/0xa91 kernel/softirq.c:298
asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706
__run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
do_softirq_own_stack+0x9d/0xd0 arch/x86/kernel/irq_64.c:77
invoke_softirq kernel/softirq.c:393 [inline]
__irq_exit_rcu kernel/softirq.c:423 [inline]
irq_exit_rcu+0x235/0x280 kernel/softirq.c:435
sysvec_apic_timer_interrupt+0x51/0xf0 arch/x86/kernel/apic/apic.c:1091
asm_sysvec_apic_timer_interrupt+0x12/0x20
arch/x86/include/asm/idtentry.h:581
unwind_next_frame+0x139a/0x1f90 arch/x86/kernel/unwind_orc.c:607
arch_stack_walk+0x81/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
kasan_set_track mm/kasan/common.c:56 [inline]
__kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
slab_post_alloc_hook mm/slab.h:518 [inline]
slab_alloc mm/slab.c:3312 [inline]
kmem_cache_alloc+0x13a/0x3a0 mm/slab.c:3482
__d_alloc+0x2a/0x950 fs/dcache.c:1709
d_alloc+0x4a/0x230 fs/dcache.c:1788
d_alloc_parallel+0xe9/0x18e0 fs/dcache.c:2540
lookup_open.isra.0+0x9ac/0x1350 fs/namei.c:3030
open_last_lookups fs/namei.c:3177 [inline]
path_openat+0x96d/0x2730 fs/namei.c:3365
do_filp_open+0x17e/0x3c0 fs/namei.c:3395
do_sys_openat2+0x16d/0x420 fs/open.c:1168
do_sys_open fs/open.c:1184 [inline]
__do_sys_open fs/open.c:1192 [inline]
__se_sys_open fs/open.c:1188 [inline]
__x64_sys_open+0x119/0x1c0 fs/open.c:1188
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
irq event stamp: 853
hardirqs last enabled at (853): []
__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline]
hardirqs last enabled at (853): []
_raw_spin_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:199
hardirqs last disabled at (852): []
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:126 [inline]
hardirqs last disabled at (852): []
_raw_spin_lock_irq+0xa4/0xd0 kernel/locking/spinlock.c:167
softirqs last enabled at (0): []
copy_process+0x1a99/0x6920 kernel/fork.c:2018
softirqs last disabled at (0): [<>] 0x0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
lock(slock-AF_BLUETOOTH-BTPROTO_SCO);
lock(slock-AF_BLUETOOTH-BTPROTO_SCO);
*** DEADLOCK ***
3 locks held by syz-executor675/31233:
#0: 88809f104f40 (>req_lock){+.+.}-{3:3}, at:
hci_dev_do_close+0xf5/0x1080 net/bluetooth/hci_core.c:1720
#1: 88809f104078 (>lock){+.+.}-{3:3}, at:
hci_dev_do_close+0x253/0x1080 net/bluetooth/hci_core.c:1757
#2: 8a9188c8 (hci_cb_list_lock){+.+.}-{3:3}, at:
hci_disconn_cfm include/net/bluetooth/hci_core.h:1435 [inline]
#2: 8a9188c8 (hci_cb_list_lock){+.+.}-{3:3}, at:
hci_conn_hash_flush+0xc7/0x220 net/bluetooth/hci_conn.c:1557
stack backtrace:
CPU: 1 PID: 31233 Comm: syz-executor675 Not tainted 5.9.0-rc4-syzkaller
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x198/0x1fd lib/dump_stack.c:118
print_usage_bug kernel/locking/lockdep.c:4020 [inline]
valid_state kernel/locking/lockdep.c:3361 [inline]
mark_lock_irq kernel/locking/lockdep.c:3560 [inline]
mark_lock.cold+0x7a/0x7f kernel/locking/lockdep.c:4006
mark_usage kernel/locking/lockdep.c:3923 [inline]
__lock_acquire+0x876/0x5570 kernel/locking/lockdep.c:4380
lock_acquire+0x1f3/0xae0 kernel/locking/lockdep.c:5006
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
