CVE-2022-49902

published 2025-05-01

CVE-2022-49902: In the Linux kernel, the following vulnerability has been resolved: block: Fix possible memory leak for rq_wb on add_disk failure kmemleak reported memory…

Priority P4 17 medium 5.5 CVSS 3.1

AV L AC L PR L UI N S U C N I N A H

In the Linux kernel, the following vulnerability has been resolved:

block: Fix possible memory leak for rq_wb on add_disk failure

kmemleak reported memory leaks in device_add_disk():

kmemleak: 3 new suspected memory leaks

unreferenced object 0xffff88800f420800 (size 512):
comm "modprobe", pid 4275, jiffies 4295639067 (age 223.512s)
hex dump (first 32 bytes):
04 00 00 00 08 00 00 00 01 00 00 00 00 00 00 00 ................
00 e1 f5 05 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[] kmalloc_trace+0x26/0x60
[] wbt_init+0x50/0x6f0
[] wbt_enable_default+0x157/0x1c0
[] blk_register_queue+0x2a4/0x420
[] device_add_disk+0x6fd/0xe40
[] nbd_dev_add+0x828/0xbf0 [nbd]
...

It is because the memory allocated in wbt_enable_default() is not
released in device_add_disk() error path.
Normally, these memory are freed in:

del_gendisk()
rq_qos_exit()
rqos->ops->exit(rqos);
wbt_exit()

So rq_qos_exit() is called to free the rq_wb memory for wbt_init().
However in the error path of device_add_disk(), only
blk_unregister_queue() is called and make rq_wb memory leaked.

Add rq_qos_exit() to the error path to fix it.

Affected

11 ranges

Vendor	Product	Version range	Fixed in
debian	linux	< linux 6.0.8-1 (bookworm)	linux 6.0.8-1 (bookworm)
linux	linux	—	—
linux	linux	>= 83cbce9574462c6b4eed6797bdaf18fae6859ab3 < 4e68c5da60cd79950bd56287ae80b39d6261f995	4e68c5da60cd79950bd56287ae80b39d6261f995
linux	linux	>= 83cbce9574462c6b4eed6797bdaf18fae6859ab3 < 528677d3b4af985445bd4ac667485ded1ed11220	528677d3b4af985445bd4ac667485ded1ed11220
linux	linux	>= 83cbce9574462c6b4eed6797bdaf18fae6859ab3 < fa81cbafbf5764ad5053512152345fab37a1fe18	fa81cbafbf5764ad5053512152345fab37a1fe18
linux	linux_kernel	—	—
linux	linux_kernel	>= 0 < 6.0.8-1	6.0.8-1
linux	linux_kernel	>= 0 < 6.0.8-1	6.0.8-1
linux	linux_kernel	>= 0 < 6.0.8-1	6.0.8-1
linux	linux_kernel	>= 5.15 < 5.15.78	5.15.78
linux	linux_kernel	>= 5.16 < 6.0.8	6.0.8

CVSS provenance

nvd v3.1 5.5 MEDIUM CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

osv 5.5 MEDIUM

vendor_debian 5.5 MEDIUM

vendor_redhat 5.5 MEDIUM

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