| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
drm/nouveau: fix stale locked mutex in nouveau_gem_ioctl_pushbuf
If VM_BIND is enabled on the client the legacy submission ioctl can't be
used, however if a client tries to do so regardless it will return an
error. In this case the clients mutex remained unlocked leading to a
deadlock inside nouveau_drm_postclose or any other nouveau ioctl call. |
| In the Linux kernel, the following vulnerability has been resolved:
NFS: Fix nfs_netfs_issue_read() xarray locking for writeback interrupt
The loop inside nfs_netfs_issue_read() currently does not disable
interrupts while iterating through pages in the xarray to submit
for NFS read. This is not safe though since after taking xa_lock,
another page in the mapping could be processed for writeback inside
an interrupt, and deadlock can occur. The fix is simple and clean
if we use xa_for_each_range(), which handles the iteration with RCU
while reducing code complexity.
The problem is easily reproduced with the following test:
mount -o vers=3,fsc 127.0.0.1:/export /mnt/nfs
dd if=/dev/zero of=/mnt/nfs/file1.bin bs=4096 count=1
echo 3 > /proc/sys/vm/drop_caches
dd if=/mnt/nfs/file1.bin of=/dev/null
umount /mnt/nfs
On the console with a lockdep-enabled kernel a message similar to
the following will be seen:
================================
WARNING: inconsistent lock state
6.7.0-lockdbg+ #10 Not tainted
--------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
test5/1708 [HC0[0]:SC0[0]:HE1:SE1] takes:
ffff888127baa598 (&xa->xa_lock#4){+.?.}-{3:3}, at:
nfs_netfs_issue_read+0x1b2/0x4b0 [nfs]
{IN-SOFTIRQ-W} state was registered at:
lock_acquire+0x144/0x380
_raw_spin_lock_irqsave+0x4e/0xa0
__folio_end_writeback+0x17e/0x5c0
folio_end_writeback+0x93/0x1b0
iomap_finish_ioend+0xeb/0x6a0
blk_update_request+0x204/0x7f0
blk_mq_end_request+0x30/0x1c0
blk_complete_reqs+0x7e/0xa0
__do_softirq+0x113/0x544
__irq_exit_rcu+0xfe/0x120
irq_exit_rcu+0xe/0x20
sysvec_call_function_single+0x6f/0x90
asm_sysvec_call_function_single+0x1a/0x20
pv_native_safe_halt+0xf/0x20
default_idle+0x9/0x20
default_idle_call+0x67/0xa0
do_idle+0x2b5/0x300
cpu_startup_entry+0x34/0x40
start_secondary+0x19d/0x1c0
secondary_startup_64_no_verify+0x18f/0x19b
irq event stamp: 176891
hardirqs last enabled at (176891): [<ffffffffa67a0be4>]
_raw_spin_unlock_irqrestore+0x44/0x60
hardirqs last disabled at (176890): [<ffffffffa67a0899>]
_raw_spin_lock_irqsave+0x79/0xa0
softirqs last enabled at (176646): [<ffffffffa515d91e>]
__irq_exit_rcu+0xfe/0x120
softirqs last disabled at (176633): [<ffffffffa515d91e>]
__irq_exit_rcu+0xfe/0x120
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&xa->xa_lock#4);
<Interrupt>
lock(&xa->xa_lock#4);
*** DEADLOCK ***
2 locks held by test5/1708:
#0: ffff888127baa498 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at:
nfs_start_io_read+0x28/0x90 [nfs]
#1: ffff888127baa650 (mapping.invalidate_lock#3){.+.+}-{4:4}, at:
page_cache_ra_unbounded+0xa4/0x280
stack backtrace:
CPU: 6 PID: 1708 Comm: test5 Kdump: loaded Not tainted 6.7.0-lockdbg+
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39
04/01/2014
Call Trace:
dump_stack_lvl+0x5b/0x90
mark_lock+0xb3f/0xd20
__lock_acquire+0x77b/0x3360
_raw_spin_lock+0x34/0x80
nfs_netfs_issue_read+0x1b2/0x4b0 [nfs]
netfs_begin_read+0x77f/0x980 [netfs]
nfs_netfs_readahead+0x45/0x60 [nfs]
nfs_readahead+0x323/0x5a0 [nfs]
read_pages+0xf3/0x5c0
page_cache_ra_unbounded+0x1c8/0x280
filemap_get_pages+0x38c/0xae0
filemap_read+0x206/0x5e0
nfs_file_read+0xb7/0x140 [nfs]
vfs_read+0x2a9/0x460
ksys_read+0xb7/0x140 |
| In the Linux kernel, the following vulnerability has been resolved:
USB: core: Fix deadlock in usb_deauthorize_interface()
Among the attribute file callback routines in
drivers/usb/core/sysfs.c, the interface_authorized_store() function is
the only one which acquires a device lock on an ancestor device: It
calls usb_deauthorize_interface(), which locks the interface's parent
USB device.
The will lead to deadlock if another process already owns that lock
and tries to remove the interface, whether through a configuration
change or because the device has been disconnected. As part of the
removal procedure, device_del() waits for all ongoing sysfs attribute
callbacks to complete. But usb_deauthorize_interface() can't complete
until the device lock has been released, and the lock won't be
released until the removal has finished.
The mechanism provided by sysfs to prevent this kind of deadlock is
to use the sysfs_break_active_protection() function, which tells sysfs
not to wait for the attribute callback.
Reported-and-tested by: Yue Sun <samsun1006219@gmail.com>
Reported by: xingwei lee <xrivendell7@gmail.com> |
| In the Linux kernel, the following vulnerability has been resolved:
USB: core: Fix deadlock in port "disable" sysfs attribute
The show and store callback routines for the "disable" sysfs attribute
file in port.c acquire the device lock for the port's parent hub
device. This can cause problems if another process has locked the hub
to remove it or change its configuration:
Removing the hub or changing its configuration requires the
hub interface to be removed, which requires the port device
to be removed, and device_del() waits until all outstanding
sysfs attribute callbacks for the ports have returned. The
lock can't be released until then.
But the disable_show() or disable_store() routine can't return
until after it has acquired the lock.
The resulting deadlock can be avoided by calling
sysfs_break_active_protection(). This will cause the sysfs core not
to wait for the attribute's callback routine to return, allowing the
removal to proceed. The disadvantage is that after making this call,
there is no guarantee that the hub structure won't be deallocated at
any moment. To prevent this, we have to acquire a reference to it
first by calling hub_get(). |
| In the Linux kernel, the following vulnerability has been resolved:
block: fix deadlock between bd_link_disk_holder and partition scan
'open_mutex' of gendisk is used to protect open/close block devices. But
in bd_link_disk_holder(), it is used to protect the creation of symlink
between holding disk and slave bdev, which introduces some issues.
When bd_link_disk_holder() is called, the driver is usually in the process
of initialization/modification and may suspend submitting io. At this
time, any io hold 'open_mutex', such as scanning partitions, can cause
deadlocks. For example, in raid:
T1 T2
bdev_open_by_dev
lock open_mutex [1]
...
efi_partition
...
md_submit_bio
md_ioctl mddev_syspend
-> suspend all io
md_add_new_disk
bind_rdev_to_array
bd_link_disk_holder
try lock open_mutex [2]
md_handle_request
-> wait mddev_resume
T1 scan partition, T2 add a new device to raid. T1 waits for T2 to resume
mddev, but T2 waits for open_mutex held by T1. Deadlock occurs.
Fix it by introducing a local mutex 'blk_holder_mutex' to replace
'open_mutex'. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: hisi_sas: Fix a deadlock issue related to automatic dump
If we issue a disabling PHY command, the device attached with it will go
offline, if a 2 bit ECC error occurs at the same time, a hung task may be
found:
[ 4613.652388] INFO: task kworker/u256:0:165233 blocked for more than 120 seconds.
[ 4613.666297] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 4613.674809] task:kworker/u256:0 state:D stack: 0 pid:165233 ppid: 2 flags:0x00000208
[ 4613.683959] Workqueue: 0000:74:02.0_disco_q sas_revalidate_domain [libsas]
[ 4613.691518] Call trace:
[ 4613.694678] __switch_to+0xf8/0x17c
[ 4613.698872] __schedule+0x660/0xee0
[ 4613.703063] schedule+0xac/0x240
[ 4613.706994] schedule_timeout+0x500/0x610
[ 4613.711705] __down+0x128/0x36c
[ 4613.715548] down+0x240/0x2d0
[ 4613.719221] hisi_sas_internal_abort_timeout+0x1bc/0x260 [hisi_sas_main]
[ 4613.726618] sas_execute_internal_abort+0x144/0x310 [libsas]
[ 4613.732976] sas_execute_internal_abort_dev+0x44/0x60 [libsas]
[ 4613.739504] hisi_sas_internal_task_abort_dev.isra.0+0xbc/0x1b0 [hisi_sas_main]
[ 4613.747499] hisi_sas_dev_gone+0x174/0x250 [hisi_sas_main]
[ 4613.753682] sas_notify_lldd_dev_gone+0xec/0x2e0 [libsas]
[ 4613.759781] sas_unregister_common_dev+0x4c/0x7a0 [libsas]
[ 4613.765962] sas_destruct_devices+0xb8/0x120 [libsas]
[ 4613.771709] sas_do_revalidate_domain.constprop.0+0x1b8/0x31c [libsas]
[ 4613.778930] sas_revalidate_domain+0x60/0xa4 [libsas]
[ 4613.784716] process_one_work+0x248/0x950
[ 4613.789424] worker_thread+0x318/0x934
[ 4613.793878] kthread+0x190/0x200
[ 4613.797810] ret_from_fork+0x10/0x18
[ 4613.802121] INFO: task kworker/u256:4:316722 blocked for more than 120 seconds.
[ 4613.816026] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 4613.824538] task:kworker/u256:4 state:D stack: 0 pid:316722 ppid: 2 flags:0x00000208
[ 4613.833670] Workqueue: 0000:74:02.0 hisi_sas_rst_work_handler [hisi_sas_main]
[ 4613.841491] Call trace:
[ 4613.844647] __switch_to+0xf8/0x17c
[ 4613.848852] __schedule+0x660/0xee0
[ 4613.853052] schedule+0xac/0x240
[ 4613.856984] schedule_timeout+0x500/0x610
[ 4613.861695] __down+0x128/0x36c
[ 4613.865542] down+0x240/0x2d0
[ 4613.869216] hisi_sas_controller_prereset+0x58/0x1fc [hisi_sas_main]
[ 4613.876324] hisi_sas_rst_work_handler+0x40/0x8c [hisi_sas_main]
[ 4613.883019] process_one_work+0x248/0x950
[ 4613.887732] worker_thread+0x318/0x934
[ 4613.892204] kthread+0x190/0x200
[ 4613.896118] ret_from_fork+0x10/0x18
[ 4613.900423] INFO: task kworker/u256:1:348985 blocked for more than 121 seconds.
[ 4613.914341] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 4613.922852] task:kworker/u256:1 state:D stack: 0 pid:348985 ppid: 2 flags:0x00000208
[ 4613.931984] Workqueue: 0000:74:02.0_event_q sas_port_event_worker [libsas]
[ 4613.939549] Call trace:
[ 4613.942702] __switch_to+0xf8/0x17c
[ 4613.946892] __schedule+0x660/0xee0
[ 4613.951083] schedule+0xac/0x240
[ 4613.955015] schedule_timeout+0x500/0x610
[ 4613.959725] wait_for_common+0x200/0x610
[ 4613.964349] wait_for_completion+0x3c/0x5c
[ 4613.969146] flush_workqueue+0x198/0x790
[ 4613.973776] sas_porte_broadcast_rcvd+0x1e8/0x320 [libsas]
[ 4613.979960] sas_port_event_worker+0x54/0xa0 [libsas]
[ 4613.985708] process_one_work+0x248/0x950
[ 4613.990420] worker_thread+0x318/0x934
[ 4613.994868] kthread+0x190/0x200
[ 4613.998800] ret_from_fork+0x10/0x18
This is because when the device goes offline, we obtain the hisi_hba
semaphore and send the ABORT_DEV command to the device. However, the
internal abort timed out due to the 2 bit ECC error and triggers automatic
dump. In addition, since the hisi_hba semaphore has been obtained, the dump
cannot be executed and the controller cannot be reset.
Therefore, the deadlocks occur on the following circular dependencies
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
spi: cadence-qspi: remove system-wide suspend helper calls from runtime PM hooks
The ->runtime_suspend() and ->runtime_resume() callbacks are not
expected to call spi_controller_suspend() and spi_controller_resume().
Remove calls to those in the cadence-qspi driver.
Those helpers have two roles currently:
- They stop/start the queue, including dealing with the kworker.
- They toggle the SPI controller SPI_CONTROLLER_SUSPENDED flag. It
requires acquiring ctlr->bus_lock_mutex.
Step one is irrelevant because cadence-qspi is not queued. Step two
however has two implications:
- A deadlock occurs, because ->runtime_resume() is called in a context
where the lock is already taken (in the ->exec_op() callback, where
the usage count is incremented).
- It would disallow all operations once the device is auto-suspended.
Here is a brief call tree highlighting the mutex deadlock:
spi_mem_exec_op()
...
spi_mem_access_start()
mutex_lock(&ctlr->bus_lock_mutex)
cqspi_exec_mem_op()
pm_runtime_resume_and_get()
cqspi_resume()
spi_controller_resume()
mutex_lock(&ctlr->bus_lock_mutex)
...
spi_mem_access_end()
mutex_unlock(&ctlr->bus_lock_mutex)
... |
| In the Linux kernel, the following vulnerability has been resolved:
dmaengine: fsl-qdma: fix SoC may hang on 16 byte unaligned read
There is chip (ls1028a) errata:
The SoC may hang on 16 byte unaligned read transactions by QDMA.
Unaligned read transactions initiated by QDMA may stall in the NOC
(Network On-Chip), causing a deadlock condition. Stalled transactions will
trigger completion timeouts in PCIe controller.
Workaround:
Enable prefetch by setting the source descriptor prefetchable bit
( SD[PF] = 1 ).
Implement this workaround. |
| In the Linux kernel, the following vulnerability has been resolved:
mptcp: fix possible deadlock in subflow diag
Syzbot and Eric reported a lockdep splat in the subflow diag:
WARNING: possible circular locking dependency detected
6.8.0-rc4-syzkaller-00212-g40b9385dd8e6 #0 Not tainted
syz-executor.2/24141 is trying to acquire lock:
ffff888045870130 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at:
tcp_diag_put_ulp net/ipv4/tcp_diag.c:100 [inline]
ffff888045870130 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at:
tcp_diag_get_aux+0x738/0x830 net/ipv4/tcp_diag.c:137
but task is already holding lock:
ffffc9000135e488 (&h->lhash2[i].lock){+.+.}-{2:2}, at: spin_lock
include/linux/spinlock.h:351 [inline]
ffffc9000135e488 (&h->lhash2[i].lock){+.+.}-{2:2}, at:
inet_diag_dump_icsk+0x39f/0x1f80 net/ipv4/inet_diag.c:1038
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&h->lhash2[i].lock){+.+.}-{2:2}:
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
__inet_hash+0x335/0xbe0 net/ipv4/inet_hashtables.c:743
inet_csk_listen_start+0x23a/0x320 net/ipv4/inet_connection_sock.c:1261
__inet_listen_sk+0x2a2/0x770 net/ipv4/af_inet.c:217
inet_listen+0xa3/0x110 net/ipv4/af_inet.c:239
rds_tcp_listen_init+0x3fd/0x5a0 net/rds/tcp_listen.c:316
rds_tcp_init_net+0x141/0x320 net/rds/tcp.c:577
ops_init+0x352/0x610 net/core/net_namespace.c:136
__register_pernet_operations net/core/net_namespace.c:1214 [inline]
register_pernet_operations+0x2cb/0x660 net/core/net_namespace.c:1283
register_pernet_device+0x33/0x80 net/core/net_namespace.c:1370
rds_tcp_init+0x62/0xd0 net/rds/tcp.c:735
do_one_initcall+0x238/0x830 init/main.c:1236
do_initcall_level+0x157/0x210 init/main.c:1298
do_initcalls+0x3f/0x80 init/main.c:1314
kernel_init_freeable+0x42f/0x5d0 init/main.c:1551
kernel_init+0x1d/0x2a0 init/main.c:1441
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242
-> #0 (k-sk_lock-AF_INET6){+.+.}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain+0x18ca/0x58e0 kernel/locking/lockdep.c:3869
__lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
lock_sock_fast include/net/sock.h:1723 [inline]
subflow_get_info+0x166/0xd20 net/mptcp/diag.c:28
tcp_diag_put_ulp net/ipv4/tcp_diag.c:100 [inline]
tcp_diag_get_aux+0x738/0x830 net/ipv4/tcp_diag.c:137
inet_sk_diag_fill+0x10ed/0x1e00 net/ipv4/inet_diag.c:345
inet_diag_dump_icsk+0x55b/0x1f80 net/ipv4/inet_diag.c:1061
__inet_diag_dump+0x211/0x3a0 net/ipv4/inet_diag.c:1263
inet_diag_dump_compat+0x1c1/0x2d0 net/ipv4/inet_diag.c:1371
netlink_dump+0x59b/0xc80 net/netlink/af_netlink.c:2264
__netlink_dump_start+0x5df/0x790 net/netlink/af_netlink.c:2370
netlink_dump_start include/linux/netlink.h:338 [inline]
inet_diag_rcv_msg_compat+0x209/0x4c0 net/ipv4/inet_diag.c:1405
sock_diag_rcv_msg+0xe7/0x410
netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543
sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:280
netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline]
netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1367
netlink_sendmsg+0xa3b/0xd70 net/netlink/af_netlink.c:1908
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0x221/0x270 net/socket.c:745
____sys_sendmsg+0x525/0x7d0 net/socket.c:2584
___sys_sendmsg net/socket.c:2638 [inline]
__sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667
do_syscall_64+0xf9/0x240
entry_SYSCALL_64_after_hwframe+0x6f/0x77
As noted by Eric we can break the lock dependency chain avoid
dumping
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: act_mirred: use the backlog for mirred ingress
The test Davide added in commit ca22da2fbd69 ("act_mirred: use the backlog
for nested calls to mirred ingress") hangs our testing VMs every 10 or so
runs, with the familiar tcp_v4_rcv -> tcp_v4_rcv deadlock reported by
lockdep.
The problem as previously described by Davide (see Link) is that
if we reverse flow of traffic with the redirect (egress -> ingress)
we may reach the same socket which generated the packet. And we may
still be holding its socket lock. The common solution to such deadlocks
is to put the packet in the Rx backlog, rather than run the Rx path
inline. Do that for all egress -> ingress reversals, not just once
we started to nest mirred calls.
In the past there was a concern that the backlog indirection will
lead to loss of error reporting / less accurate stats. But the current
workaround does not seem to address the issue. |
| In the Linux kernel, the following vulnerability has been resolved:
net: implement lockless setsockopt(SO_PEEK_OFF)
syzbot reported a lockdep violation [1] involving af_unix
support of SO_PEEK_OFF.
Since SO_PEEK_OFF is inherently not thread safe (it uses a per-socket
sk_peek_off field), there is really no point to enforce a pointless
thread safety in the kernel.
After this patch :
- setsockopt(SO_PEEK_OFF) no longer acquires the socket lock.
- skb_consume_udp() no longer has to acquire the socket lock.
- af_unix no longer needs a special version of sk_set_peek_off(),
because it does not lock u->iolock anymore.
As a followup, we could replace prot->set_peek_off to be a boolean
and avoid an indirect call, since we always use sk_set_peek_off().
[1]
WARNING: possible circular locking dependency detected
6.8.0-rc4-syzkaller-00267-g0f1dd5e91e2b #0 Not tainted
syz-executor.2/30025 is trying to acquire lock:
ffff8880765e7d80 (&u->iolock){+.+.}-{3:3}, at: unix_set_peek_off+0x26/0xa0 net/unix/af_unix.c:789
but task is already holding lock:
ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1691 [inline]
ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sockopt_lock_sock net/core/sock.c:1060 [inline]
ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sk_setsockopt+0xe52/0x3360 net/core/sock.c:1193
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (sk_lock-AF_UNIX){+.+.}-{0:0}:
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
lock_sock_nested+0x48/0x100 net/core/sock.c:3524
lock_sock include/net/sock.h:1691 [inline]
__unix_dgram_recvmsg+0x1275/0x12c0 net/unix/af_unix.c:2415
sock_recvmsg_nosec+0x18e/0x1d0 net/socket.c:1046
____sys_recvmsg+0x3c0/0x470 net/socket.c:2801
___sys_recvmsg net/socket.c:2845 [inline]
do_recvmmsg+0x474/0xae0 net/socket.c:2939
__sys_recvmmsg net/socket.c:3018 [inline]
__do_sys_recvmmsg net/socket.c:3041 [inline]
__se_sys_recvmmsg net/socket.c:3034 [inline]
__x64_sys_recvmmsg+0x199/0x250 net/socket.c:3034
do_syscall_64+0xf9/0x240
entry_SYSCALL_64_after_hwframe+0x6f/0x77
-> #0 (&u->iolock){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain+0x18ca/0x58e0 kernel/locking/lockdep.c:3869
__lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137
lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
unix_set_peek_off+0x26/0xa0 net/unix/af_unix.c:789
sk_setsockopt+0x207e/0x3360
do_sock_setsockopt+0x2fb/0x720 net/socket.c:2307
__sys_setsockopt+0x1ad/0x250 net/socket.c:2334
__do_sys_setsockopt net/socket.c:2343 [inline]
__se_sys_setsockopt net/socket.c:2340 [inline]
__x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340
do_syscall_64+0xf9/0x240
entry_SYSCALL_64_after_hwframe+0x6f/0x77
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(sk_lock-AF_UNIX);
lock(&u->iolock);
lock(sk_lock-AF_UNIX);
lock(&u->iolock);
*** DEADLOCK ***
1 lock held by syz-executor.2/30025:
#0: ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1691 [inline]
#0: ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sockopt_lock_sock net/core/sock.c:1060 [inline]
#0: ffff8880765e7930 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sk_setsockopt+0xe52/0x3360 net/core/sock.c:1193
stack backtrace:
CPU: 0 PID: 30025 Comm: syz-executor.2 Not tainted 6.8.0-rc4-syzkaller-00267-g0f1dd5e91e2b #0
Hardware name: Google Google C
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
dpll: fix possible deadlock during netlink dump operation
Recently, I've been hitting following deadlock warning during dpll pin
dump:
[52804.637962] ======================================================
[52804.638536] WARNING: possible circular locking dependency detected
[52804.639111] 6.8.0-rc2jiri+ #1 Not tainted
[52804.639529] ------------------------------------------------------
[52804.640104] python3/2984 is trying to acquire lock:
[52804.640581] ffff88810e642678 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}, at: netlink_dump+0xb3/0x780
[52804.641417]
but task is already holding lock:
[52804.642010] ffffffff83bde4c8 (dpll_lock){+.+.}-{3:3}, at: dpll_lock_dumpit+0x13/0x20
[52804.642747]
which lock already depends on the new lock.
[52804.643551]
the existing dependency chain (in reverse order) is:
[52804.644259]
-> #1 (dpll_lock){+.+.}-{3:3}:
[52804.644836] lock_acquire+0x174/0x3e0
[52804.645271] __mutex_lock+0x119/0x1150
[52804.645723] dpll_lock_dumpit+0x13/0x20
[52804.646169] genl_start+0x266/0x320
[52804.646578] __netlink_dump_start+0x321/0x450
[52804.647056] genl_family_rcv_msg_dumpit+0x155/0x1e0
[52804.647575] genl_rcv_msg+0x1ed/0x3b0
[52804.648001] netlink_rcv_skb+0xdc/0x210
[52804.648440] genl_rcv+0x24/0x40
[52804.648831] netlink_unicast+0x2f1/0x490
[52804.649290] netlink_sendmsg+0x36d/0x660
[52804.649742] __sock_sendmsg+0x73/0xc0
[52804.650165] __sys_sendto+0x184/0x210
[52804.650597] __x64_sys_sendto+0x72/0x80
[52804.651045] do_syscall_64+0x6f/0x140
[52804.651474] entry_SYSCALL_64_after_hwframe+0x46/0x4e
[52804.652001]
-> #0 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}:
[52804.652650] check_prev_add+0x1ae/0x1280
[52804.653107] __lock_acquire+0x1ed3/0x29a0
[52804.653559] lock_acquire+0x174/0x3e0
[52804.653984] __mutex_lock+0x119/0x1150
[52804.654423] netlink_dump+0xb3/0x780
[52804.654845] __netlink_dump_start+0x389/0x450
[52804.655321] genl_family_rcv_msg_dumpit+0x155/0x1e0
[52804.655842] genl_rcv_msg+0x1ed/0x3b0
[52804.656272] netlink_rcv_skb+0xdc/0x210
[52804.656721] genl_rcv+0x24/0x40
[52804.657119] netlink_unicast+0x2f1/0x490
[52804.657570] netlink_sendmsg+0x36d/0x660
[52804.658022] __sock_sendmsg+0x73/0xc0
[52804.658450] __sys_sendto+0x184/0x210
[52804.658877] __x64_sys_sendto+0x72/0x80
[52804.659322] do_syscall_64+0x6f/0x140
[52804.659752] entry_SYSCALL_64_after_hwframe+0x46/0x4e
[52804.660281]
other info that might help us debug this:
[52804.661077] Possible unsafe locking scenario:
[52804.661671] CPU0 CPU1
[52804.662129] ---- ----
[52804.662577] lock(dpll_lock);
[52804.662924] lock(nlk_cb_mutex-GENERIC);
[52804.663538] lock(dpll_lock);
[52804.664073] lock(nlk_cb_mutex-GENERIC);
[52804.664490]
The issue as follows: __netlink_dump_start() calls control->start(cb)
with nlk->cb_mutex held. In control->start(cb) the dpll_lock is taken.
Then nlk->cb_mutex is released and taken again in netlink_dump(), while
dpll_lock still being held. That leads to ABBA deadlock when another
CPU races with the same operation.
Fix this by moving dpll_lock taking into dumpit() callback which ensures
correct lock taking order. |
| In the Linux kernel, the following vulnerability has been resolved:
ASoC: rt5645: Fix deadlock in rt5645_jack_detect_work()
There is a path in rt5645_jack_detect_work(), where rt5645->jd_mutex
is left locked forever. That may lead to deadlock
when rt5645_jack_detect_work() is called for the second time.
Found by Linux Verification Center (linuxtesting.org) with SVACE. |
| In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix hang in nilfs_lookup_dirty_data_buffers()
Syzbot reported a hang issue in migrate_pages_batch() called by mbind()
and nilfs_lookup_dirty_data_buffers() called in the log writer of nilfs2.
While migrate_pages_batch() locks a folio and waits for the writeback to
complete, the log writer thread that should bring the writeback to
completion picks up the folio being written back in
nilfs_lookup_dirty_data_buffers() that it calls for subsequent log
creation and was trying to lock the folio. Thus causing a deadlock.
In the first place, it is unexpected that folios/pages in the middle of
writeback will be updated and become dirty. Nilfs2 adds a checksum to
verify the validity of the log being written and uses it for recovery at
mount, so data changes during writeback are suppressed. Since this is
broken, an unclean shutdown could potentially cause recovery to fail.
Investigation revealed that the root cause is that the wait for writeback
completion in nilfs_page_mkwrite() is conditional, and if the backing
device does not require stable writes, data may be modified without
waiting.
Fix these issues by making nilfs_page_mkwrite() wait for writeback to
finish regardless of the stable write requirement of the backing device. |
| In the Linux kernel, the following vulnerability has been resolved:
bcachefs: grab s_umount only if snapshotting
When I was testing mongodb over bcachefs with compression,
there is a lockdep warning when snapshotting mongodb data volume.
$ cat test.sh
prog=bcachefs
$prog subvolume create /mnt/data
$prog subvolume create /mnt/data/snapshots
while true;do
$prog subvolume snapshot /mnt/data /mnt/data/snapshots/$(date +%s)
sleep 1s
done
$ cat /etc/mongodb.conf
systemLog:
destination: file
logAppend: true
path: /mnt/data/mongod.log
storage:
dbPath: /mnt/data/
lockdep reports:
[ 3437.452330] ======================================================
[ 3437.452750] WARNING: possible circular locking dependency detected
[ 3437.453168] 6.7.0-rc7-custom+ #85 Tainted: G E
[ 3437.453562] ------------------------------------------------------
[ 3437.453981] bcachefs/35533 is trying to acquire lock:
[ 3437.454325] ffffa0a02b2b1418 (sb_writers#10){.+.+}-{0:0}, at: filename_create+0x62/0x190
[ 3437.454875]
but task is already holding lock:
[ 3437.455268] ffffa0a02b2b10e0 (&type->s_umount_key#48){.+.+}-{3:3}, at: bch2_fs_file_ioctl+0x232/0xc90 [bcachefs]
[ 3437.456009]
which lock already depends on the new lock.
[ 3437.456553]
the existing dependency chain (in reverse order) is:
[ 3437.457054]
-> #3 (&type->s_umount_key#48){.+.+}-{3:3}:
[ 3437.457507] down_read+0x3e/0x170
[ 3437.457772] bch2_fs_file_ioctl+0x232/0xc90 [bcachefs]
[ 3437.458206] __x64_sys_ioctl+0x93/0xd0
[ 3437.458498] do_syscall_64+0x42/0xf0
[ 3437.458779] entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ 3437.459155]
-> #2 (&c->snapshot_create_lock){++++}-{3:3}:
[ 3437.459615] down_read+0x3e/0x170
[ 3437.459878] bch2_truncate+0x82/0x110 [bcachefs]
[ 3437.460276] bchfs_truncate+0x254/0x3c0 [bcachefs]
[ 3437.460686] notify_change+0x1f1/0x4a0
[ 3437.461283] do_truncate+0x7f/0xd0
[ 3437.461555] path_openat+0xa57/0xce0
[ 3437.461836] do_filp_open+0xb4/0x160
[ 3437.462116] do_sys_openat2+0x91/0xc0
[ 3437.462402] __x64_sys_openat+0x53/0xa0
[ 3437.462701] do_syscall_64+0x42/0xf0
[ 3437.462982] entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ 3437.463359]
-> #1 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}:
[ 3437.463843] down_write+0x3b/0xc0
[ 3437.464223] bch2_write_iter+0x5b/0xcc0 [bcachefs]
[ 3437.464493] vfs_write+0x21b/0x4c0
[ 3437.464653] ksys_write+0x69/0xf0
[ 3437.464839] do_syscall_64+0x42/0xf0
[ 3437.465009] entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ 3437.465231]
-> #0 (sb_writers#10){.+.+}-{0:0}:
[ 3437.465471] __lock_acquire+0x1455/0x21b0
[ 3437.465656] lock_acquire+0xc6/0x2b0
[ 3437.465822] mnt_want_write+0x46/0x1a0
[ 3437.465996] filename_create+0x62/0x190
[ 3437.466175] user_path_create+0x2d/0x50
[ 3437.466352] bch2_fs_file_ioctl+0x2ec/0xc90 [bcachefs]
[ 3437.466617] __x64_sys_ioctl+0x93/0xd0
[ 3437.466791] do_syscall_64+0x42/0xf0
[ 3437.466957] entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ 3437.467180]
other info that might help us debug this:
[ 3437.469670] 2 locks held by bcachefs/35533:
other info that might help us debug this:
[ 3437.467507] Chain exists of:
sb_writers#10 --> &c->snapshot_create_lock --> &type->s_umount_key#48
[ 3437.467979] Possible unsafe locking scenario:
[ 3437.468223] CPU0 CPU1
[ 3437.468405] ---- ----
[ 3437.468585] rlock(&type->s_umount_key#48);
[ 3437.468758] lock(&c->snapshot_create_lock);
[ 3437.469030] lock(&type->s_umount_key#48);
[ 3437.469291] rlock(sb_writers#10);
[ 3437.469434]
*** DEADLOCK ***
[ 3437.469
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
tcp: make sure init the accept_queue's spinlocks once
When I run syz's reproduction C program locally, it causes the following
issue:
pvqspinlock: lock 0xffff9d181cd5c660 has corrupted value 0x0!
WARNING: CPU: 19 PID: 21160 at __pv_queued_spin_unlock_slowpath (kernel/locking/qspinlock_paravirt.h:508)
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
RIP: 0010:__pv_queued_spin_unlock_slowpath (kernel/locking/qspinlock_paravirt.h:508)
Code: 73 56 3a ff 90 c3 cc cc cc cc 8b 05 bb 1f 48 01 85 c0 74 05 c3 cc cc cc cc 8b 17 48 89 fe 48 c7 c7
30 20 ce 8f e8 ad 56 42 ff <0f> 0b c3 cc cc cc cc 0f 0b 0f 1f 40 00 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffa8d200604cb8 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff9d1ef60e0908
RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI: ffff9d1ef60e0900
RBP: ffff9d181cd5c280 R08: 0000000000000000 R09: 00000000ffff7fff
R10: ffffa8d200604b68 R11: ffffffff907dcdc8 R12: 0000000000000000
R13: ffff9d181cd5c660 R14: ffff9d1813a3f330 R15: 0000000000001000
FS: 00007fa110184640(0000) GS:ffff9d1ef60c0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000000 CR3: 000000011f65e000 CR4: 00000000000006f0
Call Trace:
<IRQ>
_raw_spin_unlock (kernel/locking/spinlock.c:186)
inet_csk_reqsk_queue_add (net/ipv4/inet_connection_sock.c:1321)
inet_csk_complete_hashdance (net/ipv4/inet_connection_sock.c:1358)
tcp_check_req (net/ipv4/tcp_minisocks.c:868)
tcp_v4_rcv (net/ipv4/tcp_ipv4.c:2260)
ip_protocol_deliver_rcu (net/ipv4/ip_input.c:205)
ip_local_deliver_finish (net/ipv4/ip_input.c:234)
__netif_receive_skb_one_core (net/core/dev.c:5529)
process_backlog (./include/linux/rcupdate.h:779)
__napi_poll (net/core/dev.c:6533)
net_rx_action (net/core/dev.c:6604)
__do_softirq (./arch/x86/include/asm/jump_label.h:27)
do_softirq (kernel/softirq.c:454 kernel/softirq.c:441)
</IRQ>
<TASK>
__local_bh_enable_ip (kernel/softirq.c:381)
__dev_queue_xmit (net/core/dev.c:4374)
ip_finish_output2 (./include/net/neighbour.h:540 net/ipv4/ip_output.c:235)
__ip_queue_xmit (net/ipv4/ip_output.c:535)
__tcp_transmit_skb (net/ipv4/tcp_output.c:1462)
tcp_rcv_synsent_state_process (net/ipv4/tcp_input.c:6469)
tcp_rcv_state_process (net/ipv4/tcp_input.c:6657)
tcp_v4_do_rcv (net/ipv4/tcp_ipv4.c:1929)
__release_sock (./include/net/sock.h:1121 net/core/sock.c:2968)
release_sock (net/core/sock.c:3536)
inet_wait_for_connect (net/ipv4/af_inet.c:609)
__inet_stream_connect (net/ipv4/af_inet.c:702)
inet_stream_connect (net/ipv4/af_inet.c:748)
__sys_connect (./include/linux/file.h:45 net/socket.c:2064)
__x64_sys_connect (net/socket.c:2073 net/socket.c:2070 net/socket.c:2070)
do_syscall_64 (arch/x86/entry/common.c:51 arch/x86/entry/common.c:82)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129)
RIP: 0033:0x7fa10ff05a3d
Code: 5b 41 5c c3 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89
c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d ab a3 0e 00 f7 d8 64 89 01 48
RSP: 002b:00007fa110183de8 EFLAGS: 00000202 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 0000000020000054 RCX: 00007fa10ff05a3d
RDX: 000000000000001c RSI: 0000000020000040 RDI: 0000000000000003
RBP: 00007fa110183e20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007fa110184640
R13: 0000000000000000 R14: 00007fa10fe8b060 R15: 00007fff73e23b20
</TASK>
The issue triggering process is analyzed as follows:
Thread A Thread B
tcp_v4_rcv //receive ack TCP packet inet_shutdown
tcp_check_req tcp_disconnect //disconnect sock
... tcp_set_state(sk, TCP_CLOSE)
inet_csk_complete_hashdance ...
inet_csk_reqsk_queue_add
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
io_uring: add a schedule point in io_add_buffers()
Looping ~65535 times doing kmalloc() calls can trigger soft lockups,
especially with DEBUG features (like KASAN).
[ 253.536212] watchdog: BUG: soft lockup - CPU#64 stuck for 26s! [b219417889:12575]
[ 253.544433] Modules linked in: vfat fat i2c_mux_pca954x i2c_mux spidev cdc_acm xhci_pci xhci_hcd sha3_generic gq(O)
[ 253.544451] CPU: 64 PID: 12575 Comm: b219417889 Tainted: G S O 5.17.0-smp-DEV #801
[ 253.544457] RIP: 0010:kernel_text_address (./include/asm-generic/sections.h:192 ./include/linux/kallsyms.h:29 kernel/extable.c:67 kernel/extable.c:98)
[ 253.544464] Code: 0f 93 c0 48 c7 c1 e0 63 d7 a4 48 39 cb 0f 92 c1 20 c1 0f b6 c1 5b 5d c3 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 53 48 89 fb <48> c7 c0 00 00 80 a0 41 be 01 00 00 00 48 39 c7 72 0c 48 c7 c0 40
[ 253.544468] RSP: 0018:ffff8882d8baf4c0 EFLAGS: 00000246
[ 253.544471] RAX: 1ffff1105b175e00 RBX: ffffffffa13ef09a RCX: 00000000a13ef001
[ 253.544474] RDX: ffffffffa13ef09a RSI: ffff8882d8baf558 RDI: ffffffffa13ef09a
[ 253.544476] RBP: ffff8882d8baf4d8 R08: ffff8882d8baf5e0 R09: 0000000000000004
[ 253.544479] R10: ffff8882d8baf5e8 R11: ffffffffa0d59a50 R12: ffff8882eab20380
[ 253.544481] R13: ffffffffa0d59a50 R14: dffffc0000000000 R15: 1ffff1105b175eb0
[ 253.544483] FS: 00000000016d3380(0000) GS:ffff88af48c00000(0000) knlGS:0000000000000000
[ 253.544486] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 253.544488] CR2: 00000000004af0f0 CR3: 00000002eabfa004 CR4: 00000000003706e0
[ 253.544491] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 253.544492] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 253.544494] Call Trace:
[ 253.544496] <TASK>
[ 253.544498] ? io_queue_sqe (fs/io_uring.c:7143)
[ 253.544505] __kernel_text_address (kernel/extable.c:78)
[ 253.544508] unwind_get_return_address (arch/x86/kernel/unwind_frame.c:19)
[ 253.544514] arch_stack_walk (arch/x86/kernel/stacktrace.c:27)
[ 253.544517] ? io_queue_sqe (fs/io_uring.c:7143)
[ 253.544521] stack_trace_save (kernel/stacktrace.c:123)
[ 253.544527] ____kasan_kmalloc (mm/kasan/common.c:39 mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:515)
[ 253.544531] ? ____kasan_kmalloc (mm/kasan/common.c:39 mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:515)
[ 253.544533] ? __kasan_kmalloc (mm/kasan/common.c:524)
[ 253.544535] ? kmem_cache_alloc_trace (./include/linux/kasan.h:270 mm/slab.c:3567)
[ 253.544541] ? io_issue_sqe (fs/io_uring.c:4556 fs/io_uring.c:4589 fs/io_uring.c:6828)
[ 253.544544] ? __io_queue_sqe (fs/io_uring.c:?)
[ 253.544551] __kasan_kmalloc (mm/kasan/common.c:524)
[ 253.544553] kmem_cache_alloc_trace (./include/linux/kasan.h:270 mm/slab.c:3567)
[ 253.544556] ? io_issue_sqe (fs/io_uring.c:4556 fs/io_uring.c:4589 fs/io_uring.c:6828)
[ 253.544560] io_issue_sqe (fs/io_uring.c:4556 fs/io_uring.c:4589 fs/io_uring.c:6828)
[ 253.544564] ? __kasan_slab_alloc (mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:469)
[ 253.544567] ? __kasan_slab_alloc (mm/kasan/common.c:39 mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:469)
[ 253.544569] ? kmem_cache_alloc_bulk (mm/slab.h:732 mm/slab.c:3546)
[ 253.544573] ? __io_alloc_req_refill (fs/io_uring.c:2078)
[ 253.544578] ? io_submit_sqes (fs/io_uring.c:7441)
[ 253.544581] ? __se_sys_io_uring_enter (fs/io_uring.c:10154 fs/io_uring.c:10096)
[ 253.544584] ? __x64_sys_io_uring_enter (fs/io_uring.c:10096)
[ 253.544587] ? do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
[ 253.544590] ? entry_SYSCALL_64_after_hwframe (??:?)
[ 253.544596] __io_queue_sqe (fs/io_uring.c:?)
[ 253.544600] io_queue_sqe (fs/io_uring.c:7143)
[ 253.544603] io_submit_sqe (fs/io_uring.c:?)
[ 253.544608] io_submit_sqes (fs/io_uring.c:?)
[ 253.544612] __se_sys_io_uring_enter (fs/io_uring.c:10154 fs/io_uri
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/ib_srp: Fix a deadlock
Remove the flush_workqueue(system_long_wq) call since flushing
system_long_wq is deadlock-prone and since that call is redundant with a
preceding cancel_work_sync() |
| In the Linux kernel, the following vulnerability has been resolved:
mm: vmscan: remove deadlock due to throttling failing to make progress
A soft lockup bug in kcompactd was reported in a private bugzilla with
the following visible in dmesg;
watchdog: BUG: soft lockup - CPU#33 stuck for 26s! [kcompactd0:479]
watchdog: BUG: soft lockup - CPU#33 stuck for 52s! [kcompactd0:479]
watchdog: BUG: soft lockup - CPU#33 stuck for 78s! [kcompactd0:479]
watchdog: BUG: soft lockup - CPU#33 stuck for 104s! [kcompactd0:479]
The machine had 256G of RAM with no swap and an earlier failed
allocation indicated that node 0 where kcompactd was run was potentially
unreclaimable;
Node 0 active_anon:29355112kB inactive_anon:2913528kB active_file:0kB
inactive_file:0kB unevictable:64kB isolated(anon):0kB isolated(file):0kB
mapped:8kB dirty:0kB writeback:0kB shmem:26780kB shmem_thp:
0kB shmem_pmdmapped: 0kB anon_thp: 23480320kB writeback_tmp:0kB
kernel_stack:2272kB pagetables:24500kB all_unreclaimable? yes
Vlastimil Babka investigated a crash dump and found that a task
migrating pages was trying to drain PCP lists;
PID: 52922 TASK: ffff969f820e5000 CPU: 19 COMMAND: "kworker/u128:3"
Call Trace:
__schedule
schedule
schedule_timeout
wait_for_completion
__flush_work
__drain_all_pages
__alloc_pages_slowpath.constprop.114
__alloc_pages
alloc_migration_target
migrate_pages
migrate_to_node
do_migrate_pages
cpuset_migrate_mm_workfn
process_one_work
worker_thread
kthread
ret_from_fork
This failure is specific to CONFIG_PREEMPT=n builds. The root of the
problem is that kcompact0 is not rescheduling on a CPU while a task that
has isolated a large number of the pages from the LRU is waiting on
kcompact0 to reschedule so the pages can be released. While
shrink_inactive_list() only loops once around too_many_isolated, reclaim
can continue without rescheduling if sc->skipped_deactivate == 1 which
could happen if there was no file LRU and the inactive anon list was not
low. |
| In the Linux kernel, the following vulnerability has been resolved:
net, neigh: Do not trigger immediate probes on NUD_FAILED from neigh_managed_work
syzkaller was able to trigger a deadlock for NTF_MANAGED entries [0]:
kworker/0:16/14617 is trying to acquire lock:
ffffffff8d4dd370 (&tbl->lock){++-.}-{2:2}, at: ___neigh_create+0x9e1/0x2990 net/core/neighbour.c:652
[...]
but task is already holding lock:
ffffffff8d4dd370 (&tbl->lock){++-.}-{2:2}, at: neigh_managed_work+0x35/0x250 net/core/neighbour.c:1572
The neighbor entry turned to NUD_FAILED state, where __neigh_event_send()
triggered an immediate probe as per commit cd28ca0a3dd1 ("neigh: reduce
arp latency") via neigh_probe() given table lock was held.
One option to fix this situation is to defer the neigh_probe() back to
the neigh_timer_handler() similarly as pre cd28ca0a3dd1. For the case
of NTF_MANAGED, this deferral is acceptable given this only happens on
actual failure state and regular / expected state is NUD_VALID with the
entry already present.
The fix adds a parameter to __neigh_event_send() in order to communicate
whether immediate probe is allowed or disallowed. Existing call-sites
of neigh_event_send() default as-is to immediate probe. However, the
neigh_managed_work() disables it via use of neigh_event_send_probe().
[0] <TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_deadlock_bug kernel/locking/lockdep.c:2956 [inline]
check_deadlock kernel/locking/lockdep.c:2999 [inline]
validate_chain kernel/locking/lockdep.c:3788 [inline]
__lock_acquire.cold+0x149/0x3ab kernel/locking/lockdep.c:5027
lock_acquire kernel/locking/lockdep.c:5639 [inline]
lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604
__raw_write_lock_bh include/linux/rwlock_api_smp.h:202 [inline]
_raw_write_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:334
___neigh_create+0x9e1/0x2990 net/core/neighbour.c:652
ip6_finish_output2+0x1070/0x14f0 net/ipv6/ip6_output.c:123
__ip6_finish_output net/ipv6/ip6_output.c:191 [inline]
__ip6_finish_output+0x61e/0xe90 net/ipv6/ip6_output.c:170
ip6_finish_output+0x32/0x200 net/ipv6/ip6_output.c:201
NF_HOOK_COND include/linux/netfilter.h:296 [inline]
ip6_output+0x1e4/0x530 net/ipv6/ip6_output.c:224
dst_output include/net/dst.h:451 [inline]
NF_HOOK include/linux/netfilter.h:307 [inline]
ndisc_send_skb+0xa99/0x17f0 net/ipv6/ndisc.c:508
ndisc_send_ns+0x3a9/0x840 net/ipv6/ndisc.c:650
ndisc_solicit+0x2cd/0x4f0 net/ipv6/ndisc.c:742
neigh_probe+0xc2/0x110 net/core/neighbour.c:1040
__neigh_event_send+0x37d/0x1570 net/core/neighbour.c:1201
neigh_event_send include/net/neighbour.h:470 [inline]
neigh_managed_work+0x162/0x250 net/core/neighbour.c:1574
process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307
worker_thread+0x657/0x1110 kernel/workqueue.c:2454
kthread+0x2e9/0x3a0 kernel/kthread.c:377
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK> |
