| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| An issue was discovered in PyTorch v2.5 and v2.7.1. Omission of profiler.stop() can cause torch.profiler.profile (PythonTracer) to crash or hang during finalization, leading to a Denial of Service (DoS). |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix deadlock between rcu_tasks_trace and event_mutex.
Fix the following deadlock:
CPU A
_free_event()
perf_kprobe_destroy()
mutex_lock(&event_mutex)
perf_trace_event_unreg()
synchronize_rcu_tasks_trace()
There are several paths where _free_event() grabs event_mutex
and calls sync_rcu_tasks_trace. Above is one such case.
CPU B
bpf_prog_test_run_syscall()
rcu_read_lock_trace()
bpf_prog_run_pin_on_cpu()
bpf_prog_load()
bpf_tracing_func_proto()
trace_set_clr_event()
mutex_lock(&event_mutex)
Delegate trace_set_clr_event() to workqueue to avoid
such lock dependency. |
| In the Linux kernel, the following vulnerability has been resolved:
s390/mm: Fix in_atomic() handling in do_secure_storage_access()
Kernel user spaces accesses to not exported pages in atomic context
incorrectly try to resolve the page fault.
With debug options enabled call traces like this can be seen:
BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1523
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 419074, name: qemu-system-s39
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
INFO: lockdep is turned off.
Preemption disabled at:
[<00000383ea47cfa2>] copy_page_from_iter_atomic+0xa2/0x8a0
CPU: 12 UID: 0 PID: 419074 Comm: qemu-system-s39
Tainted: G W 6.16.0-20250531.rc0.git0.69b3a602feac.63.fc42.s390x+debug #1 PREEMPT
Tainted: [W]=WARN
Hardware name: IBM 3931 A01 703 (LPAR)
Call Trace:
[<00000383e990d282>] dump_stack_lvl+0xa2/0xe8
[<00000383e99bf152>] __might_resched+0x292/0x2d0
[<00000383eaa7c374>] down_read+0x34/0x2d0
[<00000383e99432f8>] do_secure_storage_access+0x108/0x360
[<00000383eaa724b0>] __do_pgm_check+0x130/0x220
[<00000383eaa842e4>] pgm_check_handler+0x114/0x160
[<00000383ea47d028>] copy_page_from_iter_atomic+0x128/0x8a0
([<00000383ea47d016>] copy_page_from_iter_atomic+0x116/0x8a0)
[<00000383e9c45eae>] generic_perform_write+0x16e/0x310
[<00000383e9eb87f4>] ext4_buffered_write_iter+0x84/0x160
[<00000383e9da0de4>] vfs_write+0x1c4/0x460
[<00000383e9da123c>] ksys_write+0x7c/0x100
[<00000383eaa7284e>] __do_syscall+0x15e/0x280
[<00000383eaa8417e>] system_call+0x6e/0x90
INFO: lockdep is turned off.
It is not allowed to take the mmap_lock while in atomic context. Therefore
handle such a secure storage access fault as if the accessed page is not
mapped: the uaccess function will return -EFAULT, and the caller has to
deal with this. Usually this means that the access is retried in process
context, which allows to resolve the page fault (or in this case export the
page). |
| In the Linux kernel, the following vulnerability has been resolved:
um: work around sched_yield not yielding in time-travel mode
sched_yield by a userspace may not actually cause scheduling in
time-travel mode as no time has passed. In the case seen it appears to
be a badly implemented userspace spinlock in ASAN. Unfortunately, with
time-travel it causes an extreme slowdown or even deadlock depending on
the kernel configuration (CONFIG_UML_MAX_USERSPACE_ITERATIONS).
Work around it by accounting time to the process whenever it executes a
sched_yield syscall. |
| In the Linux kernel, the following vulnerability has been resolved:
PM: hibernate: Avoid deadlock in hibernate_compressor_param_set()
syzbot reported a deadlock in lock_system_sleep() (see below).
The write operation to "/sys/module/hibernate/parameters/compressor"
conflicts with the registration of ieee80211 device, resulting in a deadlock
when attempting to acquire system_transition_mutex under param_lock.
To avoid this deadlock, change hibernate_compressor_param_set() to use
mutex_trylock() for attempting to acquire system_transition_mutex and
return -EBUSY when it fails.
Task flags need not be saved or adjusted before calling
mutex_trylock(&system_transition_mutex) because the caller is not going
to end up waiting for this mutex and if it runs concurrently with system
suspend in progress, it will be frozen properly when it returns to user
space.
syzbot report:
syz-executor895/5833 is trying to acquire lock:
ffffffff8e0828c8 (system_transition_mutex){+.+.}-{4:4}, at: lock_system_sleep+0x87/0xa0 kernel/power/main.c:56
but task is already holding lock:
ffffffff8e07dc68 (param_lock){+.+.}-{4:4}, at: kernel_param_lock kernel/params.c:607 [inline]
ffffffff8e07dc68 (param_lock){+.+.}-{4:4}, at: param_attr_store+0xe6/0x300 kernel/params.c:586
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (param_lock){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:585 [inline]
__mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730
ieee80211_rate_control_ops_get net/mac80211/rate.c:220 [inline]
rate_control_alloc net/mac80211/rate.c:266 [inline]
ieee80211_init_rate_ctrl_alg+0x18d/0x6b0 net/mac80211/rate.c:1015
ieee80211_register_hw+0x20cd/0x4060 net/mac80211/main.c:1531
mac80211_hwsim_new_radio+0x304e/0x54e0 drivers/net/wireless/virtual/mac80211_hwsim.c:5558
init_mac80211_hwsim+0x432/0x8c0 drivers/net/wireless/virtual/mac80211_hwsim.c:6910
do_one_initcall+0x128/0x700 init/main.c:1257
do_initcall_level init/main.c:1319 [inline]
do_initcalls init/main.c:1335 [inline]
do_basic_setup init/main.c:1354 [inline]
kernel_init_freeable+0x5c7/0x900 init/main.c:1568
kernel_init+0x1c/0x2b0 init/main.c:1457
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
-> #2 (rtnl_mutex){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:585 [inline]
__mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730
wg_pm_notification drivers/net/wireguard/device.c:80 [inline]
wg_pm_notification+0x49/0x180 drivers/net/wireguard/device.c:64
notifier_call_chain+0xb7/0x410 kernel/notifier.c:85
notifier_call_chain_robust kernel/notifier.c:120 [inline]
blocking_notifier_call_chain_robust kernel/notifier.c:345 [inline]
blocking_notifier_call_chain_robust+0xc9/0x170 kernel/notifier.c:333
pm_notifier_call_chain_robust+0x27/0x60 kernel/power/main.c:102
snapshot_open+0x189/0x2b0 kernel/power/user.c:77
misc_open+0x35a/0x420 drivers/char/misc.c:179
chrdev_open+0x237/0x6a0 fs/char_dev.c:414
do_dentry_open+0x735/0x1c40 fs/open.c:956
vfs_open+0x82/0x3f0 fs/open.c:1086
do_open fs/namei.c:3830 [inline]
path_openat+0x1e88/0x2d80 fs/namei.c:3989
do_filp_open+0x20c/0x470 fs/namei.c:4016
do_sys_openat2+0x17a/0x1e0 fs/open.c:1428
do_sys_open fs/open.c:1443 [inline]
__do_sys_openat fs/open.c:1459 [inline]
__se_sys_openat fs/open.c:1454 [inline]
__x64_sys_openat+0x175/0x210 fs/open.c:1454
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #1 ((pm_chain_head).rwsem){++++}-{4:4}:
down_read+0x9a/0x330 kernel/locking/rwsem.c:1524
blocking_notifier_call_chain_robust kerne
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
net: vlan: don't propagate flags on open
With the device instance lock, there is now a possibility of a deadlock:
[ 1.211455] ============================================
[ 1.211571] WARNING: possible recursive locking detected
[ 1.211687] 6.14.0-rc5-01215-g032756b4ca7a-dirty #5 Not tainted
[ 1.211823] --------------------------------------------
[ 1.211936] ip/184 is trying to acquire lock:
[ 1.212032] ffff8881024a4c30 (&dev->lock){+.+.}-{4:4}, at: dev_set_allmulti+0x4e/0xb0
[ 1.212207]
[ 1.212207] but task is already holding lock:
[ 1.212332] ffff8881024a4c30 (&dev->lock){+.+.}-{4:4}, at: dev_open+0x50/0xb0
[ 1.212487]
[ 1.212487] other info that might help us debug this:
[ 1.212626] Possible unsafe locking scenario:
[ 1.212626]
[ 1.212751] CPU0
[ 1.212815] ----
[ 1.212871] lock(&dev->lock);
[ 1.212944] lock(&dev->lock);
[ 1.213016]
[ 1.213016] *** DEADLOCK ***
[ 1.213016]
[ 1.213143] May be due to missing lock nesting notation
[ 1.213143]
[ 1.213294] 3 locks held by ip/184:
[ 1.213371] #0: ffffffff838b53e0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock+0x1b/0xa0
[ 1.213543] #1: ffffffff84e5fc70 (&net->rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock+0x37/0xa0
[ 1.213727] #2: ffff8881024a4c30 (&dev->lock){+.+.}-{4:4}, at: dev_open+0x50/0xb0
[ 1.213895]
[ 1.213895] stack backtrace:
[ 1.213991] CPU: 0 UID: 0 PID: 184 Comm: ip Not tainted 6.14.0-rc5-01215-g032756b4ca7a-dirty #5
[ 1.213993] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
[ 1.213994] Call Trace:
[ 1.213995] <TASK>
[ 1.213996] dump_stack_lvl+0x8e/0xd0
[ 1.214000] print_deadlock_bug+0x28b/0x2a0
[ 1.214020] lock_acquire+0xea/0x2a0
[ 1.214027] __mutex_lock+0xbf/0xd40
[ 1.214038] dev_set_allmulti+0x4e/0xb0 # real_dev->flags & IFF_ALLMULTI
[ 1.214040] vlan_dev_open+0xa5/0x170 # ndo_open on vlandev
[ 1.214042] __dev_open+0x145/0x270
[ 1.214046] __dev_change_flags+0xb0/0x1e0
[ 1.214051] netif_change_flags+0x22/0x60 # IFF_UP vlandev
[ 1.214053] dev_change_flags+0x61/0xb0 # for each device in group from dev->vlan_info
[ 1.214055] vlan_device_event+0x766/0x7c0 # on netdevsim0
[ 1.214058] notifier_call_chain+0x78/0x120
[ 1.214062] netif_open+0x6d/0x90
[ 1.214064] dev_open+0x5b/0xb0 # locks netdevsim0
[ 1.214066] bond_enslave+0x64c/0x1230
[ 1.214075] do_set_master+0x175/0x1e0 # on netdevsim0
[ 1.214077] do_setlink+0x516/0x13b0
[ 1.214094] rtnl_newlink+0xaba/0xb80
[ 1.214132] rtnetlink_rcv_msg+0x440/0x490
[ 1.214144] netlink_rcv_skb+0xeb/0x120
[ 1.214150] netlink_unicast+0x1f9/0x320
[ 1.214153] netlink_sendmsg+0x346/0x3f0
[ 1.214157] __sock_sendmsg+0x86/0xb0
[ 1.214160] ____sys_sendmsg+0x1c8/0x220
[ 1.214164] ___sys_sendmsg+0x28f/0x2d0
[ 1.214179] __x64_sys_sendmsg+0xef/0x140
[ 1.214184] do_syscall_64+0xec/0x1d0
[ 1.214190] entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 1.214191] RIP: 0033:0x7f2d1b4a7e56
Device setup:
netdevsim0 (down)
^ ^
bond netdevsim1.100@netdevsim1 allmulticast=on (down)
When we enslave the lower device (netdevsim0) which has a vlan, we
propagate vlan's allmuti/promisc flags during ndo_open. This causes
(re)locking on of the real_dev.
Propagate allmulti/promisc on flags change, not on the open. There
is a slight semantics change that vlans that are down now propagate
the flags, but this seems unlikely to result in the real issues.
Reproducer:
echo 0 1 > /sys/bus/netdevsim/new_device
dev_path=$(ls -d /sys/bus/netdevsim/devices/netdevsim0/net/*)
dev=$(echo $dev_path | rev | cut -d/ -f1 | rev)
ip link set dev $dev name netdevsim0
ip link set dev netdevsim0 up
ip link add link netdevsim0 name netdevsim0.100 type vlan id 100
ip link set dev netdevsim0.100 allm
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
PCI: vmd: Make vmd_dev::cfg_lock a raw_spinlock_t type
The access to the PCI config space via pci_ops::read and pci_ops::write is
a low-level hardware access. The functions can be accessed with disabled
interrupts even on PREEMPT_RT. The pci_lock is a raw_spinlock_t for this
purpose.
A spinlock_t becomes a sleeping lock on PREEMPT_RT, so it cannot be
acquired with disabled interrupts. The vmd_dev::cfg_lock is accessed in
the same context as the pci_lock.
Make vmd_dev::cfg_lock a raw_spinlock_t type so it can be used with
interrupts disabled.
This was reported as:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
Call Trace:
rt_spin_lock+0x4e/0x130
vmd_pci_read+0x8d/0x100 [vmd]
pci_user_read_config_byte+0x6f/0xe0
pci_read_config+0xfe/0x290
sysfs_kf_bin_read+0x68/0x90
[bigeasy: reword commit message]
Tested-off-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
[kwilczynski: commit log]
[bhelgaas: add back report info from
https://lore.kernel.org/lkml/20241218115951.83062-1-ryotkkr98@gmail.com/] |
| In the Linux kernel, the following vulnerability has been resolved:
gpio: rcar: Use raw_spinlock to protect register access
Use raw_spinlock in order to fix spurious messages about invalid context
when spinlock debugging is enabled. The lock is only used to serialize
register access.
[ 4.239592] =============================
[ 4.239595] [ BUG: Invalid wait context ]
[ 4.239599] 6.13.0-rc7-arm64-renesas-05496-gd088502a519f #35 Not tainted
[ 4.239603] -----------------------------
[ 4.239606] kworker/u8:5/76 is trying to lock:
[ 4.239609] ffff0000091898a0 (&p->lock){....}-{3:3}, at: gpio_rcar_config_interrupt_input_mode+0x34/0x164
[ 4.239641] other info that might help us debug this:
[ 4.239643] context-{5:5}
[ 4.239646] 5 locks held by kworker/u8:5/76:
[ 4.239651] #0: ffff0000080fb148 ((wq_completion)async){+.+.}-{0:0}, at: process_one_work+0x190/0x62c
[ 4.250180] OF: /soc/sound@ec500000/ports/port@0/endpoint: Read of boolean property 'frame-master' with a value.
[ 4.254094] #1: ffff80008299bd80 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: process_one_work+0x1b8/0x62c
[ 4.254109] #2: ffff00000920c8f8
[ 4.258345] OF: /soc/sound@ec500000/ports/port@1/endpoint: Read of boolean property 'bitclock-master' with a value.
[ 4.264803] (&dev->mutex){....}-{4:4}, at: __device_attach_async_helper+0x3c/0xdc
[ 4.264820] #3: ffff00000a50ca40 (request_class#2){+.+.}-{4:4}, at: __setup_irq+0xa0/0x690
[ 4.264840] #4:
[ 4.268872] OF: /soc/sound@ec500000/ports/port@1/endpoint: Read of boolean property 'frame-master' with a value.
[ 4.273275] ffff00000a50c8c8 (lock_class){....}-{2:2}, at: __setup_irq+0xc4/0x690
[ 4.296130] renesas_sdhi_internal_dmac ee100000.mmc: mmc1 base at 0x00000000ee100000, max clock rate 200 MHz
[ 4.304082] stack backtrace:
[ 4.304086] CPU: 1 UID: 0 PID: 76 Comm: kworker/u8:5 Not tainted 6.13.0-rc7-arm64-renesas-05496-gd088502a519f #35
[ 4.304092] Hardware name: Renesas Salvator-X 2nd version board based on r8a77965 (DT)
[ 4.304097] Workqueue: async async_run_entry_fn
[ 4.304106] Call trace:
[ 4.304110] show_stack+0x14/0x20 (C)
[ 4.304122] dump_stack_lvl+0x6c/0x90
[ 4.304131] dump_stack+0x14/0x1c
[ 4.304138] __lock_acquire+0xdfc/0x1584
[ 4.426274] lock_acquire+0x1c4/0x33c
[ 4.429942] _raw_spin_lock_irqsave+0x5c/0x80
[ 4.434307] gpio_rcar_config_interrupt_input_mode+0x34/0x164
[ 4.440061] gpio_rcar_irq_set_type+0xd4/0xd8
[ 4.444422] __irq_set_trigger+0x5c/0x178
[ 4.448435] __setup_irq+0x2e4/0x690
[ 4.452012] request_threaded_irq+0xc4/0x190
[ 4.456285] devm_request_threaded_irq+0x7c/0xf4
[ 4.459398] ata1: link resume succeeded after 1 retries
[ 4.460902] mmc_gpiod_request_cd_irq+0x68/0xe0
[ 4.470660] mmc_start_host+0x50/0xac
[ 4.474327] mmc_add_host+0x80/0xe4
[ 4.477817] tmio_mmc_host_probe+0x2b0/0x440
[ 4.482094] renesas_sdhi_probe+0x488/0x6f4
[ 4.486281] renesas_sdhi_internal_dmac_probe+0x60/0x78
[ 4.491509] platform_probe+0x64/0xd8
[ 4.495178] really_probe+0xb8/0x2a8
[ 4.498756] __driver_probe_device+0x74/0x118
[ 4.503116] driver_probe_device+0x3c/0x154
[ 4.507303] __device_attach_driver+0xd4/0x160
[ 4.511750] bus_for_each_drv+0x84/0xe0
[ 4.515588] __device_attach_async_helper+0xb0/0xdc
[ 4.520470] async_run_entry_fn+0x30/0xd8
[ 4.524481] process_one_work+0x210/0x62c
[ 4.528494] worker_thread+0x1ac/0x340
[ 4.532245] kthread+0x10c/0x110
[ 4.535476] ret_from_fork+0x10/0x20 |
| In the Linux kernel, the following vulnerability has been resolved:
PCI: Avoid pci_dev_lock() AB/BA deadlock with sriov_numvfs_store()
The sysfs sriov_numvfs_store() path acquires the device lock before the
config space access lock:
sriov_numvfs_store
device_lock # A (1) acquire device lock
sriov_configure
vfio_pci_sriov_configure # (for example)
vfio_pci_core_sriov_configure
pci_disable_sriov
sriov_disable
pci_cfg_access_lock
pci_wait_cfg # B (4) wait for dev->block_cfg_access == 0
Previously, pci_dev_lock() acquired the config space access lock before the
device lock:
pci_dev_lock
pci_cfg_access_lock
dev->block_cfg_access = 1 # B (2) set dev->block_cfg_access = 1
device_lock # A (3) wait for device lock
Any path that uses pci_dev_lock(), e.g., pci_reset_function(), may
deadlock with sriov_numvfs_store() if the operations occur in the sequence
(1) (2) (3) (4).
Avoid the deadlock by reversing the order in pci_dev_lock() so it acquires
the device lock before the config space access lock, the same as the
sriov_numvfs_store() path.
[bhelgaas: combined and adapted commit log from Jay Zhou's independent
subsequent posting:
https://lore.kernel.org/r/20220404062539.1710-1-jianjay.zhou@huawei.com] |
| In the Linux kernel, the following vulnerability has been resolved:
net/9p: use a dedicated spinlock for trans_fd
Shamelessly copying the explanation from Tetsuo Handa's suggested
patch[1] (slightly reworded):
syzbot is reporting inconsistent lock state in p9_req_put()[2],
for p9_tag_remove() from p9_req_put() from IRQ context is using
spin_lock_irqsave() on "struct p9_client"->lock but trans_fd
(not from IRQ context) is using spin_lock().
Since the locks actually protect different things in client.c and in
trans_fd.c, just replace trans_fd.c's lock by a new one specific to the
transport (client.c's protect the idr for fid/tag allocations,
while trans_fd.c's protects its own req list and request status field
that acts as the transport's state machine) |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: lpfc: Move cfg_log_verbose check before calling lpfc_dmp_dbg()
In an attempt to log message 0126 with LOG_TRACE_EVENT, the following hard
lockup call trace hangs the system.
Call Trace:
_raw_spin_lock_irqsave+0x32/0x40
lpfc_dmp_dbg.part.32+0x28/0x220 [lpfc]
lpfc_cmpl_els_fdisc+0x145/0x460 [lpfc]
lpfc_sli_cancel_jobs+0x92/0xd0 [lpfc]
lpfc_els_flush_cmd+0x43c/0x670 [lpfc]
lpfc_els_flush_all_cmd+0x37/0x60 [lpfc]
lpfc_sli4_async_event_proc+0x956/0x1720 [lpfc]
lpfc_do_work+0x1485/0x1d70 [lpfc]
kthread+0x112/0x130
ret_from_fork+0x1f/0x40
Kernel panic - not syncing: Hard LOCKUP
The same CPU tries to claim the phba->port_list_lock twice.
Move the cfg_log_verbose checks as part of the lpfc_printf_vlog() and
lpfc_printf_log() macros before calling lpfc_dmp_dbg(). There is no need
to take the phba->port_list_lock within lpfc_dmp_dbg(). |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: lpfc: Fix SCSI I/O completion and abort handler deadlock
During stress I/O tests with 500+ vports, hard LOCKUP call traces are
observed.
CPU A:
native_queued_spin_lock_slowpath+0x192
_raw_spin_lock_irqsave+0x32
lpfc_handle_fcp_err+0x4c6
lpfc_fcp_io_cmd_wqe_cmpl+0x964
lpfc_sli4_fp_handle_cqe+0x266
__lpfc_sli4_process_cq+0x105
__lpfc_sli4_hba_process_cq+0x3c
lpfc_cq_poll_hdler+0x16
irq_poll_softirq+0x76
__softirqentry_text_start+0xe4
irq_exit+0xf7
do_IRQ+0x7f
CPU B:
native_queued_spin_lock_slowpath+0x5b
_raw_spin_lock+0x1c
lpfc_abort_handler+0x13e
scmd_eh_abort_handler+0x85
process_one_work+0x1a7
worker_thread+0x30
kthread+0x112
ret_from_fork+0x1f
Diagram of lockup:
CPUA CPUB
---- ----
lpfc_cmd->buf_lock
phba->hbalock
lpfc_cmd->buf_lock
phba->hbalock
Fix by reordering the taking of the lpfc_cmd->buf_lock and phba->hbalock in
lpfc_abort_handler routine so that it tries to take the lpfc_cmd->buf_lock
first before phba->hbalock. |
| In the Linux kernel, the following vulnerability has been resolved:
drivers: staging: rtl8192e: Fix deadlock in rtllib_beacons_stop()
There is a deadlock in rtllib_beacons_stop(), which is shown
below:
(Thread 1) | (Thread 2)
| rtllib_send_beacon()
rtllib_beacons_stop() | mod_timer()
spin_lock_irqsave() //(1) | (wait a time)
... | rtllib_send_beacon_cb()
del_timer_sync() | spin_lock_irqsave() //(2)
(wait timer to stop) | ...
We hold ieee->beacon_lock in position (1) of thread 1 and
use del_timer_sync() to wait timer to stop, but timer handler
also need ieee->beacon_lock in position (2) of thread 2.
As a result, rtllib_beacons_stop() will block forever.
This patch extracts del_timer_sync() from the protection of
spin_lock_irqsave(), which could let timer handler to obtain
the needed lock. |
| In the Linux kernel, the following vulnerability has been resolved:
drivers: usb: host: Fix deadlock in oxu_bus_suspend()
There is a deadlock in oxu_bus_suspend(), which is shown below:
(Thread 1) | (Thread 2)
| timer_action()
oxu_bus_suspend() | mod_timer()
spin_lock_irq() //(1) | (wait a time)
... | oxu_watchdog()
del_timer_sync() | spin_lock_irq() //(2)
(wait timer to stop) | ...
We hold oxu->lock in position (1) of thread 1, and use
del_timer_sync() to wait timer to stop, but timer handler
also need oxu->lock in position (2) of thread 2. As a result,
oxu_bus_suspend() will block forever.
This patch extracts del_timer_sync() from the protection of
spin_lock_irq(), which could let timer handler to obtain
the needed lock. |
| In the Linux kernel, the following vulnerability has been resolved:
drivers: staging: rtl8192u: Fix deadlock in ieee80211_beacons_stop()
There is a deadlock in ieee80211_beacons_stop(), which is shown below:
(Thread 1) | (Thread 2)
| ieee80211_send_beacon()
ieee80211_beacons_stop() | mod_timer()
spin_lock_irqsave() //(1) | (wait a time)
... | ieee80211_send_beacon_cb()
del_timer_sync() | spin_lock_irqsave() //(2)
(wait timer to stop) | ...
We hold ieee->beacon_lock in position (1) of thread 1 and use
del_timer_sync() to wait timer to stop, but timer handler
also need ieee->beacon_lock in position (2) of thread 2.
As a result, ieee80211_beacons_stop() will block forever.
This patch extracts del_timer_sync() from the protection of
spin_lock_irqsave(), which could let timer handler to obtain
the needed lock. |
| In the Linux kernel, the following vulnerability has been resolved:
drivers: tty: serial: Fix deadlock in sa1100_set_termios()
There is a deadlock in sa1100_set_termios(), which is shown
below:
(Thread 1) | (Thread 2)
| sa1100_enable_ms()
sa1100_set_termios() | mod_timer()
spin_lock_irqsave() //(1) | (wait a time)
... | sa1100_timeout()
del_timer_sync() | spin_lock_irqsave() //(2)
(wait timer to stop) | ...
We hold sport->port.lock in position (1) of thread 1 and
use del_timer_sync() to wait timer to stop, but timer handler
also need sport->port.lock in position (2) of thread 2. As a result,
sa1100_set_termios() will block forever.
This patch moves del_timer_sync() before spin_lock_irqsave()
in order to prevent the deadlock. |
| In the Linux kernel, the following vulnerability has been resolved:
drivers: staging: rtl8192eu: Fix deadlock in rtw_joinbss_event_prehandle
There is a deadlock in rtw_joinbss_event_prehandle(), which is shown below:
(Thread 1) | (Thread 2)
| _set_timer()
rtw_joinbss_event_prehandle()| mod_timer()
spin_lock_bh() //(1) | (wait a time)
... | rtw_join_timeout_handler()
| _rtw_join_timeout_handler()
del_timer_sync() | spin_lock_bh() //(2)
(wait timer to stop) | ...
We hold pmlmepriv->lock in position (1) of thread 1 and
use del_timer_sync() to wait timer to stop, but timer handler
also need pmlmepriv->lock in position (2) of thread 2.
As a result, rtw_joinbss_event_prehandle() will block forever.
This patch extracts del_timer_sync() from the protection of
spin_lock_bh(), which could let timer handler to obtain
the needed lock. What`s more, we change spin_lock_bh() to
spin_lock_irq() in _rtw_join_timeout_handler() in order to
prevent deadlock. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: get rid of warning on transaction commit when using flushoncommit
When using the flushoncommit mount option, during almost every transaction
commit we trigger a warning from __writeback_inodes_sb_nr():
$ cat fs/fs-writeback.c:
(...)
static void __writeback_inodes_sb_nr(struct super_block *sb, ...
{
(...)
WARN_ON(!rwsem_is_locked(&sb->s_umount));
(...)
}
(...)
The trace produced in dmesg looks like the following:
[947.473890] WARNING: CPU: 5 PID: 930 at fs/fs-writeback.c:2610 __writeback_inodes_sb_nr+0x7e/0xb3
[947.481623] Modules linked in: nfsd nls_cp437 cifs asn1_decoder cifs_arc4 fscache cifs_md4 ipmi_ssif
[947.489571] CPU: 5 PID: 930 Comm: btrfs-transacti Not tainted 95.16.3-srb-asrock-00001-g36437ad63879 #186
[947.497969] RIP: 0010:__writeback_inodes_sb_nr+0x7e/0xb3
[947.502097] Code: 24 10 4c 89 44 24 18 c6 (...)
[947.519760] RSP: 0018:ffffc90000777e10 EFLAGS: 00010246
[947.523818] RAX: 0000000000000000 RBX: 0000000000963300 RCX: 0000000000000000
[947.529765] RDX: 0000000000000000 RSI: 000000000000fa51 RDI: ffffc90000777e50
[947.535740] RBP: ffff888101628a90 R08: ffff888100955800 R09: ffff888100956000
[947.541701] R10: 0000000000000002 R11: 0000000000000001 R12: ffff888100963488
[947.547645] R13: ffff888100963000 R14: ffff888112fb7200 R15: ffff888100963460
[947.553621] FS: 0000000000000000(0000) GS:ffff88841fd40000(0000) knlGS:0000000000000000
[947.560537] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[947.565122] CR2: 0000000008be50c4 CR3: 000000000220c000 CR4: 00000000001006e0
[947.571072] Call Trace:
[947.572354] <TASK>
[947.573266] btrfs_commit_transaction+0x1f1/0x998
[947.576785] ? start_transaction+0x3ab/0x44e
[947.579867] ? schedule_timeout+0x8a/0xdd
[947.582716] transaction_kthread+0xe9/0x156
[947.585721] ? btrfs_cleanup_transaction.isra.0+0x407/0x407
[947.590104] kthread+0x131/0x139
[947.592168] ? set_kthread_struct+0x32/0x32
[947.595174] ret_from_fork+0x22/0x30
[947.597561] </TASK>
[947.598553] ---[ end trace 644721052755541c ]---
This is because we started using writeback_inodes_sb() to flush delalloc
when committing a transaction (when using -o flushoncommit), in order to
avoid deadlocks with filesystem freeze operations. This change was made
by commit ce8ea7cc6eb313 ("btrfs: don't call btrfs_start_delalloc_roots
in flushoncommit"). After that change we started producing that warning,
and every now and then a user reports this since the warning happens too
often, it spams dmesg/syslog, and a user is unsure if this reflects any
problem that might compromise the filesystem's reliability.
We can not just lock the sb->s_umount semaphore before calling
writeback_inodes_sb(), because that would at least deadlock with
filesystem freezing, since at fs/super.c:freeze_super() sync_filesystem()
is called while we are holding that semaphore in write mode, and that can
trigger a transaction commit, resulting in a deadlock. It would also
trigger the same type of deadlock in the unmount path. Possibly, it could
also introduce some other locking dependencies that lockdep would report.
To fix this call try_to_writeback_inodes_sb() instead of
writeback_inodes_sb(), because that will try to read lock sb->s_umount
and then will only call writeback_inodes_sb() if it was able to lock it.
This is fine because the cases where it can't read lock sb->s_umount
are during a filesystem unmount or during a filesystem freeze - in those
cases sb->s_umount is write locked and sync_filesystem() is called, which
calls writeback_inodes_sb(). In other words, in all cases where we can't
take a read lock on sb->s_umount, writeback is already being triggered
elsewhere.
An alternative would be to call btrfs_start_delalloc_roots() with a
number of pages different from LONG_MAX, for example matching the number
of delalloc bytes we currently have, in
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
drm/vc4: Fix deadlock on DSI device attach error
DSI device attach to DSI host will be done with host device's lock
held.
Un-registering host in "device attach" error path (ex: probe retry)
will result in deadlock with below call trace and non operational
DSI display.
Startup Call trace:
[ 35.043036] rt_mutex_slowlock.constprop.21+0x184/0x1b8
[ 35.043048] mutex_lock_nested+0x7c/0xc8
[ 35.043060] device_del+0x4c/0x3e8
[ 35.043075] device_unregister+0x20/0x40
[ 35.043082] mipi_dsi_remove_device_fn+0x18/0x28
[ 35.043093] device_for_each_child+0x68/0xb0
[ 35.043105] mipi_dsi_host_unregister+0x40/0x90
[ 35.043115] vc4_dsi_host_attach+0xf0/0x120 [vc4]
[ 35.043199] mipi_dsi_attach+0x30/0x48
[ 35.043209] tc358762_probe+0x128/0x164 [tc358762]
[ 35.043225] mipi_dsi_drv_probe+0x28/0x38
[ 35.043234] really_probe+0xc0/0x318
[ 35.043244] __driver_probe_device+0x80/0xe8
[ 35.043254] driver_probe_device+0xb8/0x118
[ 35.043263] __device_attach_driver+0x98/0xe8
[ 35.043273] bus_for_each_drv+0x84/0xd8
[ 35.043281] __device_attach+0xf0/0x150
[ 35.043290] device_initial_probe+0x1c/0x28
[ 35.043300] bus_probe_device+0xa4/0xb0
[ 35.043308] deferred_probe_work_func+0xa0/0xe0
[ 35.043318] process_one_work+0x254/0x700
[ 35.043330] worker_thread+0x4c/0x448
[ 35.043339] kthread+0x19c/0x1a8
[ 35.043348] ret_from_fork+0x10/0x20
Shutdown Call trace:
[ 365.565417] Call trace:
[ 365.565423] __switch_to+0x148/0x200
[ 365.565452] __schedule+0x340/0x9c8
[ 365.565467] schedule+0x48/0x110
[ 365.565479] schedule_timeout+0x3b0/0x448
[ 365.565496] wait_for_completion+0xac/0x138
[ 365.565509] __flush_work+0x218/0x4e0
[ 365.565523] flush_work+0x1c/0x28
[ 365.565536] wait_for_device_probe+0x68/0x158
[ 365.565550] device_shutdown+0x24/0x348
[ 365.565561] kernel_restart_prepare+0x40/0x50
[ 365.565578] kernel_restart+0x20/0x70
[ 365.565591] __do_sys_reboot+0x10c/0x220
[ 365.565605] __arm64_sys_reboot+0x2c/0x38
[ 365.565619] invoke_syscall+0x4c/0x110
[ 365.565634] el0_svc_common.constprop.3+0xfc/0x120
[ 365.565648] do_el0_svc+0x2c/0x90
[ 365.565661] el0_svc+0x4c/0xf0
[ 365.565671] el0t_64_sync_handler+0x90/0xb8
[ 365.565682] el0t_64_sync+0x180/0x184 |
| In the Linux kernel, the following vulnerability has been resolved:
USB: core: Fix hang in usb_kill_urb by adding memory barriers
The syzbot fuzzer has identified a bug in which processes hang waiting
for usb_kill_urb() to return. It turns out the issue is not unlinking
the URB; that works just fine. Rather, the problem arises when the
wakeup notification that the URB has completed is not received.
The reason is memory-access ordering on SMP systems. In outline form,
usb_kill_urb() and __usb_hcd_giveback_urb() operating concurrently on
different CPUs perform the following actions:
CPU 0 CPU 1
---------------------------- ---------------------------------
usb_kill_urb(): __usb_hcd_giveback_urb():
... ...
atomic_inc(&urb->reject); atomic_dec(&urb->use_count);
... ...
wait_event(usb_kill_urb_queue,
atomic_read(&urb->use_count) == 0);
if (atomic_read(&urb->reject))
wake_up(&usb_kill_urb_queue);
Confining your attention to urb->reject and urb->use_count, you can
see that the overall pattern of accesses on CPU 0 is:
write urb->reject, then read urb->use_count;
whereas the overall pattern of accesses on CPU 1 is:
write urb->use_count, then read urb->reject.
This pattern is referred to in memory-model circles as SB (for "Store
Buffering"), and it is well known that without suitable enforcement of
the desired order of accesses -- in the form of memory barriers -- it
is entirely possible for one or both CPUs to execute their reads ahead
of their writes. The end result will be that sometimes CPU 0 sees the
old un-decremented value of urb->use_count while CPU 1 sees the old
un-incremented value of urb->reject. Consequently CPU 0 ends up on
the wait queue and never gets woken up, leading to the observed hang
in usb_kill_urb().
The same pattern of accesses occurs in usb_poison_urb() and the
failure pathway of usb_hcd_submit_urb().
The problem is fixed by adding suitable memory barriers. To provide
proper memory-access ordering in the SB pattern, a full barrier is
required on both CPUs. The atomic_inc() and atomic_dec() accesses
themselves don't provide any memory ordering, but since they are
present, we can use the optimized smp_mb__after_atomic() memory
barrier in the various routines to obtain the desired effect.
This patch adds the necessary memory barriers. |
