| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
s390/qeth: fix deadlock during failing recovery
Commit 0b9902c1fcc5 ("s390/qeth: fix deadlock during recovery") removed
taking discipline_mutex inside qeth_do_reset(), fixing potential
deadlocks. An error path was missed though, that still takes
discipline_mutex and thus has the original deadlock potential.
Intermittent deadlocks were seen when a qeth channel path is configured
offline, causing a race between qeth_do_reset and ccwgroup_remove.
Call qeth_set_offline() directly in the qeth_do_reset() error case and
then a new variant of ccwgroup_set_offline(), without taking
discipline_mutex. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: core: sysfs: Fix hang when device state is set via sysfs
This fixes a regression added with:
commit f0f82e2476f6 ("scsi: core: Fix capacity set to zero after
offlinining device")
The problem is that after iSCSI recovery, iscsid will call into the kernel
to set the dev's state to running, and with that patch we now call
scsi_rescan_device() with the state_mutex held. If the SCSI error handler
thread is just starting to test the device in scsi_send_eh_cmnd() then it's
going to try to grab the state_mutex.
We are then stuck, because when scsi_rescan_device() tries to send its I/O
scsi_queue_rq() calls -> scsi_host_queue_ready() -> scsi_host_in_recovery()
which will return true (the host state is still in recovery) and I/O will
just be requeued. scsi_send_eh_cmnd() will then never be able to grab the
state_mutex to finish error handling.
To prevent the deadlock move the rescan-related code to after we drop the
state_mutex.
This also adds a check for if we are already in the running state. This
prevents extra scans and helps the iscsid case where if the transport class
has already onlined the device during its recovery process then we don't
need userspace to do it again plus possibly block that daemon. |
| In the Linux kernel, the following vulnerability has been resolved:
ASoC: Intel: soc-acpi-intel-rpl-match: add missing empty item
There is no links_num in struct snd_soc_acpi_mach {}, and we test
!link->num_adr as a condition to end the loop in hda_sdw_machine_select().
So an empty item in struct snd_soc_acpi_link_adr array is required. |
| In the Linux kernel, the following vulnerability has been resolved:
firmware: qcom: uefisecapp: Fix deadlock in qcuefi_acquire()
If the __qcuefi pointer is not set, then in the original code, we would
hold onto the lock. That means that if we tried to set it later, then
it would cause a deadlock. Drop the lock on the error path. That's
what all the callers are expecting. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe/client: fix deadlock in show_meminfo()
There is a real deadlock as well as sleeping in atomic() bug in here, if
the bo put happens to be the last ref, since bo destruction wants to
grab the same spinlock and sleeping locks. Fix that by dropping the ref
using xe_bo_put_deferred(), and moving the final commit outside of the
lock. Dropping the lock around the put is tricky since the bo can go
out of scope and delete itself from the list, making it difficult to
navigate to the next list entry.
(cherry picked from commit 0083b8e6f11d7662283a267d4ce7c966812ffd8a) |
| In the Linux kernel, the following vulnerability has been resolved:
libfs: fix infinite directory reads for offset dir
After we switch tmpfs dir operations from simple_dir_operations to
simple_offset_dir_operations, every rename happened will fill new dentry
to dest dir's maple tree(&SHMEM_I(inode)->dir_offsets->mt) with a free
key starting with octx->newx_offset, and then set newx_offset equals to
free key + 1. This will lead to infinite readdir combine with rename
happened at the same time, which fail generic/736 in xfstests(detail show
as below).
1. create 5000 files(1 2 3...) under one dir
2. call readdir(man 3 readdir) once, and get one entry
3. rename(entry, "TEMPFILE"), then rename("TEMPFILE", entry)
4. loop 2~3, until readdir return nothing or we loop too many
times(tmpfs break test with the second condition)
We choose the same logic what commit 9b378f6ad48cf ("btrfs: fix infinite
directory reads") to fix it, record the last_index when we open dir, and
do not emit the entry which index >= last_index. The file->private_data
now used in offset dir can use directly to do this, and we also update
the last_index when we llseek the dir file.
[brauner: only update last_index after seek when offset is zero like Jan suggested] |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: ufs: core: Fix deadlock during RTC update
There is a deadlock when runtime suspend waits for the flush of RTC work,
and the RTC work calls ufshcd_rpm_get_sync() to wait for runtime resume.
Here is deadlock backtrace:
kworker/0:1 D 4892.876354 10 10971 4859 0x4208060 0x8 10 0 120 670730152367
ptr f0ffff80c2e40000 0 1 0x00000001 0x000000ff 0x000000ff 0x000000ff
<ffffffee5e71ddb0> __switch_to+0x1a8/0x2d4
<ffffffee5e71e604> __schedule+0x684/0xa98
<ffffffee5e71ea60> schedule+0x48/0xc8
<ffffffee5e725f78> schedule_timeout+0x48/0x170
<ffffffee5e71fb74> do_wait_for_common+0x108/0x1b0
<ffffffee5e71efe0> wait_for_completion+0x44/0x60
<ffffffee5d6de968> __flush_work+0x39c/0x424
<ffffffee5d6decc0> __cancel_work_sync+0xd8/0x208
<ffffffee5d6dee2c> cancel_delayed_work_sync+0x14/0x28
<ffffffee5e2551b8> __ufshcd_wl_suspend+0x19c/0x480
<ffffffee5e255fb8> ufshcd_wl_runtime_suspend+0x3c/0x1d4
<ffffffee5dffd80c> scsi_runtime_suspend+0x78/0xc8
<ffffffee5df93580> __rpm_callback+0x94/0x3e0
<ffffffee5df90b0c> rpm_suspend+0x2d4/0x65c
<ffffffee5df91448> __pm_runtime_suspend+0x80/0x114
<ffffffee5dffd95c> scsi_runtime_idle+0x38/0x6c
<ffffffee5df912f4> rpm_idle+0x264/0x338
<ffffffee5df90f14> __pm_runtime_idle+0x80/0x110
<ffffffee5e24ce44> ufshcd_rtc_work+0x128/0x1e4
<ffffffee5d6e3a40> process_one_work+0x26c/0x650
<ffffffee5d6e65c8> worker_thread+0x260/0x3d8
<ffffffee5d6edec8> kthread+0x110/0x134
<ffffffee5d616b18> ret_from_fork+0x10/0x20
Skip updating RTC if RPM state is not RPM_ACTIVE. |
| In the Linux kernel, the following vulnerability has been resolved:
net: wan: fsl_qmc_hdlc: Convert carrier_lock spinlock to a mutex
The carrier_lock spinlock protects the carrier detection. While it is
held, framer_get_status() is called which in turn takes a mutex.
This is not correct and can lead to a deadlock.
A run with PROVE_LOCKING enabled detected the issue:
[ BUG: Invalid wait context ]
...
c204ddbc (&framer->mutex){+.+.}-{3:3}, at: framer_get_status+0x40/0x78
other info that might help us debug this:
context-{4:4}
2 locks held by ifconfig/146:
#0: c0926a38 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x12c/0x664
#1: c2006a40 (&qmc_hdlc->carrier_lock){....}-{2:2}, at: qmc_hdlc_framer_set_carrier+0x30/0x98
Avoid the spinlock usage and convert carrier_lock to a mutex. |
| In the Linux kernel, the following vulnerability has been resolved:
block: fix deadlock between sd_remove & sd_release
Our test report the following hung task:
[ 2538.459400] INFO: task "kworker/0:0":7 blocked for more than 188 seconds.
[ 2538.459427] Call trace:
[ 2538.459430] __switch_to+0x174/0x338
[ 2538.459436] __schedule+0x628/0x9c4
[ 2538.459442] schedule+0x7c/0xe8
[ 2538.459447] schedule_preempt_disabled+0x24/0x40
[ 2538.459453] __mutex_lock+0x3ec/0xf04
[ 2538.459456] __mutex_lock_slowpath+0x14/0x24
[ 2538.459459] mutex_lock+0x30/0xd8
[ 2538.459462] del_gendisk+0xdc/0x350
[ 2538.459466] sd_remove+0x30/0x60
[ 2538.459470] device_release_driver_internal+0x1c4/0x2c4
[ 2538.459474] device_release_driver+0x18/0x28
[ 2538.459478] bus_remove_device+0x15c/0x174
[ 2538.459483] device_del+0x1d0/0x358
[ 2538.459488] __scsi_remove_device+0xa8/0x198
[ 2538.459493] scsi_forget_host+0x50/0x70
[ 2538.459497] scsi_remove_host+0x80/0x180
[ 2538.459502] usb_stor_disconnect+0x68/0xf4
[ 2538.459506] usb_unbind_interface+0xd4/0x280
[ 2538.459510] device_release_driver_internal+0x1c4/0x2c4
[ 2538.459514] device_release_driver+0x18/0x28
[ 2538.459518] bus_remove_device+0x15c/0x174
[ 2538.459523] device_del+0x1d0/0x358
[ 2538.459528] usb_disable_device+0x84/0x194
[ 2538.459532] usb_disconnect+0xec/0x300
[ 2538.459537] hub_event+0xb80/0x1870
[ 2538.459541] process_scheduled_works+0x248/0x4dc
[ 2538.459545] worker_thread+0x244/0x334
[ 2538.459549] kthread+0x114/0x1bc
[ 2538.461001] INFO: task "fsck.":15415 blocked for more than 188 seconds.
[ 2538.461014] Call trace:
[ 2538.461016] __switch_to+0x174/0x338
[ 2538.461021] __schedule+0x628/0x9c4
[ 2538.461025] schedule+0x7c/0xe8
[ 2538.461030] blk_queue_enter+0xc4/0x160
[ 2538.461034] blk_mq_alloc_request+0x120/0x1d4
[ 2538.461037] scsi_execute_cmd+0x7c/0x23c
[ 2538.461040] ioctl_internal_command+0x5c/0x164
[ 2538.461046] scsi_set_medium_removal+0x5c/0xb0
[ 2538.461051] sd_release+0x50/0x94
[ 2538.461054] blkdev_put+0x190/0x28c
[ 2538.461058] blkdev_release+0x28/0x40
[ 2538.461063] __fput+0xf8/0x2a8
[ 2538.461066] __fput_sync+0x28/0x5c
[ 2538.461070] __arm64_sys_close+0x84/0xe8
[ 2538.461073] invoke_syscall+0x58/0x114
[ 2538.461078] el0_svc_common+0xac/0xe0
[ 2538.461082] do_el0_svc+0x1c/0x28
[ 2538.461087] el0_svc+0x38/0x68
[ 2538.461090] el0t_64_sync_handler+0x68/0xbc
[ 2538.461093] el0t_64_sync+0x1a8/0x1ac
T1: T2:
sd_remove
del_gendisk
__blk_mark_disk_dead
blk_freeze_queue_start
++q->mq_freeze_depth
bdev_release
mutex_lock(&disk->open_mutex)
sd_release
scsi_execute_cmd
blk_queue_enter
wait_event(!q->mq_freeze_depth)
mutex_lock(&disk->open_mutex)
SCSI does not set GD_OWNS_QUEUE, so QUEUE_FLAG_DYING is not set in
this scenario. This is a classic ABBA deadlock. To fix the deadlock,
make sure we don't try to acquire disk->open_mutex after freezing
the queue. |
| In the Linux kernel, the following vulnerability has been resolved:
ionic: use dev_consume_skb_any outside of napi
If we're not in a NAPI softirq context, we need to be careful
about how we call napi_consume_skb(), specifically we need to
call it with budget==0 to signal to it that we're not in a
safe context.
This was found while running some configuration stress testing
of traffic and a change queue config loop running, and this
curious note popped out:
[ 4371.402645] BUG: using smp_processor_id() in preemptible [00000000] code: ethtool/20545
[ 4371.402897] caller is napi_skb_cache_put+0x16/0x80
[ 4371.403120] CPU: 25 PID: 20545 Comm: ethtool Kdump: loaded Tainted: G OE 6.10.0-rc3-netnext+ #8
[ 4371.403302] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 01/23/2021
[ 4371.403460] Call Trace:
[ 4371.403613] <TASK>
[ 4371.403758] dump_stack_lvl+0x4f/0x70
[ 4371.403904] check_preemption_disabled+0xc1/0xe0
[ 4371.404051] napi_skb_cache_put+0x16/0x80
[ 4371.404199] ionic_tx_clean+0x18a/0x240 [ionic]
[ 4371.404354] ionic_tx_cq_service+0xc4/0x200 [ionic]
[ 4371.404505] ionic_tx_flush+0x15/0x70 [ionic]
[ 4371.404653] ? ionic_lif_qcq_deinit.isra.23+0x5b/0x70 [ionic]
[ 4371.404805] ionic_txrx_deinit+0x71/0x190 [ionic]
[ 4371.404956] ionic_reconfigure_queues+0x5f5/0xff0 [ionic]
[ 4371.405111] ionic_set_ringparam+0x2e8/0x3e0 [ionic]
[ 4371.405265] ethnl_set_rings+0x1f1/0x300
[ 4371.405418] ethnl_default_set_doit+0xbb/0x160
[ 4371.405571] genl_family_rcv_msg_doit+0xff/0x130
[...]
I found that ionic_tx_clean() calls napi_consume_skb() which calls
napi_skb_cache_put(), but before that last call is the note
/* Zero budget indicate non-NAPI context called us, like netpoll */
and
DEBUG_NET_WARN_ON_ONCE(!in_softirq());
Those are pretty big hints that we're doing it wrong. We can pass a
context hint down through the calls to let ionic_tx_clean() know what
we're doing so it can call napi_consume_skb() correctly. |
| In the Linux kernel, the following vulnerability has been resolved:
eth: sungem: remove .ndo_poll_controller to avoid deadlocks
Erhard reports netpoll warnings from sungem:
netpoll_send_skb_on_dev(): eth0 enabled interrupts in poll (gem_start_xmit+0x0/0x398)
WARNING: CPU: 1 PID: 1 at net/core/netpoll.c:370 netpoll_send_skb+0x1fc/0x20c
gem_poll_controller() disables interrupts, which may sleep.
We can't sleep in netpoll, it has interrupts disabled completely.
Strangely, gem_poll_controller() doesn't even poll the completions,
and instead acts as if an interrupt has fired so it just schedules
NAPI and exits. None of this has been necessary for years, since
netpoll invokes NAPI directly. |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: Reload only IB representors upon lag disable/enable
On lag disable, the bond IB device along with all of its
representors are destroyed, and then the slaves' representors get reloaded.
In case the slave IB representor load fails, the eswitch error flow
unloads all representors, including ethernet representors, where the
netdevs get detached and removed from lag bond. Such flow is inaccurate
as the lag driver is not responsible for loading/unloading ethernet
representors. Furthermore, the flow described above begins by holding
lag lock to prevent bond changes during disable flow. However, when
reaching the ethernet representors detachment from lag, the lag lock is
required again, triggering the following deadlock:
Call trace:
__switch_to+0xf4/0x148
__schedule+0x2c8/0x7d0
schedule+0x50/0xe0
schedule_preempt_disabled+0x18/0x28
__mutex_lock.isra.13+0x2b8/0x570
__mutex_lock_slowpath+0x1c/0x28
mutex_lock+0x4c/0x68
mlx5_lag_remove_netdev+0x3c/0x1a0 [mlx5_core]
mlx5e_uplink_rep_disable+0x70/0xa0 [mlx5_core]
mlx5e_detach_netdev+0x6c/0xb0 [mlx5_core]
mlx5e_netdev_change_profile+0x44/0x138 [mlx5_core]
mlx5e_netdev_attach_nic_profile+0x28/0x38 [mlx5_core]
mlx5e_vport_rep_unload+0x184/0x1b8 [mlx5_core]
mlx5_esw_offloads_rep_load+0xd8/0xe0 [mlx5_core]
mlx5_eswitch_reload_reps+0x74/0xd0 [mlx5_core]
mlx5_disable_lag+0x130/0x138 [mlx5_core]
mlx5_lag_disable_change+0x6c/0x70 [mlx5_core] // hold ldev->lock
mlx5_devlink_eswitch_mode_set+0xc0/0x410 [mlx5_core]
devlink_nl_cmd_eswitch_set_doit+0xdc/0x180
genl_family_rcv_msg_doit.isra.17+0xe8/0x138
genl_rcv_msg+0xe4/0x220
netlink_rcv_skb+0x44/0x108
genl_rcv+0x40/0x58
netlink_unicast+0x198/0x268
netlink_sendmsg+0x1d4/0x418
sock_sendmsg+0x54/0x60
__sys_sendto+0xf4/0x120
__arm64_sys_sendto+0x30/0x40
el0_svc_common+0x8c/0x120
do_el0_svc+0x30/0xa0
el0_svc+0x20/0x30
el0_sync_handler+0x90/0xb8
el0_sync+0x160/0x180
Thus, upon lag enable/disable, load and unload only the IB representors
of the slaves preventing the deadlock mentioned above.
While at it, refactor the mlx5_esw_offloads_rep_load() function to have
a static helper method for its internal logic, in symmetry with the
representor unload design. |
| In the Linux kernel, the following vulnerability has been resolved:
Revert "media: v4l2-ctrls: show all owned controls in log_status"
This reverts commit 9801b5b28c6929139d6fceeee8d739cc67bb2739.
This patch introduced a potential deadlock scenario:
[Wed May 8 10:02:06 2024] Possible unsafe locking scenario:
[Wed May 8 10:02:06 2024] CPU0 CPU1
[Wed May 8 10:02:06 2024] ---- ----
[Wed May 8 10:02:06 2024] lock(vivid_ctrls:1620:(hdl_vid_cap)->_lock);
[Wed May 8 10:02:06 2024] lock(vivid_ctrls:1608:(hdl_user_vid)->_lock);
[Wed May 8 10:02:06 2024] lock(vivid_ctrls:1620:(hdl_vid_cap)->_lock);
[Wed May 8 10:02:06 2024] lock(vivid_ctrls:1608:(hdl_user_vid)->_lock);
For now just revert. |
| In the Linux kernel, the following vulnerability has been resolved:
Reapply "drm/qxl: simplify qxl_fence_wait"
This reverts commit 07ed11afb68d94eadd4ffc082b97c2331307c5ea.
Stephen Rostedt reports:
"I went to run my tests on my VMs and the tests hung on boot up.
Unfortunately, the most I ever got out was:
[ 93.607888] Testing event system initcall: OK
[ 93.667730] Running tests on all trace events:
[ 93.669757] Testing all events: OK
[ 95.631064] ------------[ cut here ]------------
Timed out after 60 seconds"
and further debugging points to a possible circular locking dependency
between the console_owner locking and the worker pool locking.
Reverting the commit allows Steve's VM to boot to completion again.
[ This may obviously result in the "[TTM] Buffer eviction failed"
messages again, which was the reason for that original revert. But at
this point this seems preferable to a non-booting system... ] |
| In the Linux kernel, the following vulnerability has been resolved:
mm: use memalloc_nofs_save() in page_cache_ra_order()
See commit f2c817bed58d ("mm: use memalloc_nofs_save in readahead path"),
ensure that page_cache_ra_order() do not attempt to reclaim file-backed
pages too, or it leads to a deadlock, found issue when test ext4 large
folio.
INFO: task DataXceiver for:7494 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:DataXceiver for state:D stack:0 pid:7494 ppid:1 flags:0x00000200
Call trace:
__switch_to+0x14c/0x240
__schedule+0x82c/0xdd0
schedule+0x58/0xf0
io_schedule+0x24/0xa0
__folio_lock+0x130/0x300
migrate_pages_batch+0x378/0x918
migrate_pages+0x350/0x700
compact_zone+0x63c/0xb38
compact_zone_order+0xc0/0x118
try_to_compact_pages+0xb0/0x280
__alloc_pages_direct_compact+0x98/0x248
__alloc_pages+0x510/0x1110
alloc_pages+0x9c/0x130
folio_alloc+0x20/0x78
filemap_alloc_folio+0x8c/0x1b0
page_cache_ra_order+0x174/0x308
ondemand_readahead+0x1c8/0x2b8
page_cache_async_ra+0x68/0xb8
filemap_readahead.isra.0+0x64/0xa8
filemap_get_pages+0x3fc/0x5b0
filemap_splice_read+0xf4/0x280
ext4_file_splice_read+0x2c/0x48 [ext4]
vfs_splice_read.part.0+0xa8/0x118
splice_direct_to_actor+0xbc/0x288
do_splice_direct+0x9c/0x108
do_sendfile+0x328/0x468
__arm64_sys_sendfile64+0x8c/0x148
invoke_syscall+0x4c/0x118
el0_svc_common.constprop.0+0xc8/0xf0
do_el0_svc+0x24/0x38
el0_svc+0x4c/0x1f8
el0t_64_sync_handler+0xc0/0xc8
el0t_64_sync+0x188/0x190 |
| In the Linux kernel, the following vulnerability has been resolved:
batman-adv: Avoid infinite loop trying to resize local TT
If the MTU of one of an attached interface becomes too small to transmit
the local translation table then it must be resized to fit inside all
fragments (when enabled) or a single packet.
But if the MTU becomes too low to transmit even the header + the VLAN
specific part then the resizing of the local TT will never succeed. This
can for example happen when the usable space is 110 bytes and 11 VLANs are
on top of batman-adv. In this case, at least 116 byte would be needed.
There will just be an endless spam of
batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (110)
in the log but the function will never finish. Problem here is that the
timeout will be halved all the time and will then stagnate at 0 and
therefore never be able to reduce the table even more.
There are other scenarios possible with a similar result. The number of
BATADV_TT_CLIENT_NOPURGE entries in the local TT can for example be too
high to fit inside a packet. Such a scenario can therefore happen also with
only a single VLAN + 7 non-purgable addresses - requiring at least 120
bytes.
While this should be handled proactively when:
* interface with too low MTU is added
* VLAN is added
* non-purgeable local mac is added
* MTU of an attached interface is reduced
* fragmentation setting gets disabled (which most likely requires dropping
attached interfaces)
not all of these scenarios can be prevented because batman-adv is only
consuming events without the the possibility to prevent these actions
(non-purgable MAC address added, MTU of an attached interface is reduced).
It is therefore necessary to also make sure that the code is able to handle
also the situations when there were already incompatible system
configuration are present. |
| In the Linux kernel, the following vulnerability has been resolved:
virtio_net: Do not send RSS key if it is not supported
There is a bug when setting the RSS options in virtio_net that can break
the whole machine, getting the kernel into an infinite loop.
Running the following command in any QEMU virtual machine with virtionet
will reproduce this problem:
# ethtool -X eth0 hfunc toeplitz
This is how the problem happens:
1) ethtool_set_rxfh() calls virtnet_set_rxfh()
2) virtnet_set_rxfh() calls virtnet_commit_rss_command()
3) virtnet_commit_rss_command() populates 4 entries for the rss
scatter-gather
4) Since the command above does not have a key, then the last
scatter-gatter entry will be zeroed, since rss_key_size == 0.
sg_buf_size = vi->rss_key_size;
5) This buffer is passed to qemu, but qemu is not happy with a buffer
with zero length, and do the following in virtqueue_map_desc() (QEMU
function):
if (!sz) {
virtio_error(vdev, "virtio: zero sized buffers are not allowed");
6) virtio_error() (also QEMU function) set the device as broken
vdev->broken = true;
7) Qemu bails out, and do not repond this crazy kernel.
8) The kernel is waiting for the response to come back (function
virtnet_send_command())
9) The kernel is waiting doing the following :
while (!virtqueue_get_buf(vi->cvq, &tmp) &&
!virtqueue_is_broken(vi->cvq))
cpu_relax();
10) None of the following functions above is true, thus, the kernel
loops here forever. Keeping in mind that virtqueue_is_broken() does
not look at the qemu `vdev->broken`, so, it never realizes that the
vitio is broken at QEMU side.
Fix it by not sending RSS commands if the feature is not available in
the device. |
| 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:
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--- |
