null_blk: fix null-ptr-dereference while configuring 'power' and 'submit_queues'
Writing 'power' and 'submit_queues' concurrently will trigger kernel
panic:
Test script:
modprobe null_blk nr_devices=0
mkdir -p /sys/kernel/config/nullb/nullb0
while true; do echo 1 > submit_queues; echo 4 > submit_queues; done &
while true; do echo 1 > power; echo 0 > power; done
Test result:
BUG: kernel NULL pointer dereference, address: 0000000000000148
Oops: 0000 [#1] PREEMPT SMP
RIP: 0010:__lock_acquire+0x41d/0x28f0
Call Trace:
<TASK>
lock_acquire+0x121/0x450
down_write+0x5f/0x1d0
simple_recursive_removal+0x12f/0x5c0
blk_mq_debugfs_unregister_hctxs+0x7c/0x100
blk_mq_update_nr_hw_queues+0x4a3/0x720
nullb_update_nr_hw_queues+0x71/0xf0 [null_blk]
nullb_device_submit_queues_store+0x79/0xf0 [null_blk]
configfs_write_iter+0x119/0x1e0
vfs_write+0x326/0x730
ksys_write+0x74/0x150
This is because del_gendisk() can concurrent with
blk_mq_update_nr_hw_queues():
nullb_device_power_store nullb_apply_submit_queues
null_del_dev
del_gendisk
nullb_update_nr_hw_queues
if (!dev->nullb)
// still set while gendisk is deleted
return 0
blk_mq_update_nr_hw_queues
dev->nullb = NULL
Fix this problem by resuing the global mutex to protect
nullb_device_power_store() and nullb_update_nr_hw_queues() from configfs.
Metrics
Affected Vendors & Products
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
Mon, 02 Dec 2024 08:15:00 +0000
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Thu, 10 Oct 2024 12:15:00 +0000
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ssvc
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Thu, 10 Oct 2024 11:45:00 +0000
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Wed, 11 Sep 2024 18:30:00 +0000
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ssvc
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Wed, 11 Sep 2024 13:30:00 +0000
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ssvc
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Mon, 09 Sep 2024 14:00:00 +0000
Type | Values Removed | Values Added |
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First Time appeared |
Linux
Linux linux Kernel |
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CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
Vendors & Products |
Linux
Linux linux Kernel |
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Metrics |
cvssV3_1
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cvssV3_1
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-05-04T09:11:07.932Z
Reserved: 2024-06-21T10:13:16.284Z
Link: CVE-2024-36478

Updated: 2024-08-02T03:37:05.181Z

Status : Modified
Published: 2024-06-21T11:15:10.360
Modified: 2024-12-02T08:15:05.787
Link: CVE-2024-36478


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