block: Fix possible memory leak for rq_wb on add_disk failure

Description

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: [<00000000d3662699>] kmalloc_trace+0x26/0x60 [<00000000edc7aadc>] wbt_init+0x50/0x6f0 [<0000000069601d16>] wbt_enable_default+0x157/0x1c0 [<0000000028fc393f>] blk_register_queue+0x2a4/0x420 [<000000007345a042>] device_add_disk+0x6fd/0xe40 [<0000000060e6aab0>] 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.

Scores

EPSS (exploitation in 30 days)

0.20% · top 90% of all CVEs (5 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.

Weakness

• CWE-401 Missing Release of Memory after Effective Lifetime (opens in a new tab)All about CWE-401 and its CVEs

Affected products

• Linux · Linux

  • affected 83cbce9574462c6b4eed6797bdaf18fae6859ab3 – < 4e68c5da60cd79950bd56287ae80b39d6261f995
  • affected 83cbce9574462c6b4eed6797bdaf18fae6859ab3 – < 528677d3b4af985445bd4ac667485ded1ed11220
  • affected 83cbce9574462c6b4eed6797bdaf18fae6859ab3 – < fa81cbafbf5764ad5053512152345fab37a1fe18

• Linux · Linux

  • affected 5.15
  • unaffected < 5.15
  • unaffected 5.15.78 – ≤ 5.15.*
  • unaffected 6.0.8 – ≤ 6.0.*
  • unaffected 6.1 – ≤ *

References (3)

• https://git.kernel.org/stable/c/4e68c5da60cd79950bd56287ae80b39d6261f995 (opens in a new tab)
• https://git.kernel.org/stable/c/528677d3b4af985445bd4ac667485ded1ed11220 (opens in a new tab)
• https://git.kernel.org/stable/c/fa81cbafbf5764ad5053512152345fab37a1fe18 (opens in a new tab)

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2022-49902](https://trackcve.app/badge/CVE-2022-49902.svg)](https://trackcve.app/cve/CVE-2022-49902)

Record last updated 11 May 2026, 19:08 UTC.