md: fix a crash in mempool_free

Description

In the Linux kernel, the following vulnerability has been resolved: md: fix a crash in mempool_free There's a crash in mempool_free when running the lvm test shell/lvchange-rebuild-raid.sh. The reason for the crash is this: * super_written calls atomic_dec_and_test(&mddev->pending_writes) and wake_up(&mddev->sb_wait). Then it calls rdev_dec_pending(rdev, mddev) and bio_put(bio). * so, the process that waited on sb_wait and that is woken up is racing with bio_put(bio). * if the process wins the race, it calls bioset_exit before bio_put(bio) is executed. * bio_put(bio) attempts to free a bio into a destroyed bio set - causing a crash in mempool_free. We fix this bug by moving bio_put before atomic_dec_and_test. We also move rdev_dec_pending before atomic_dec_and_test as suggested by Neil Brown. The function md_end_flush has a similar bug - we must call bio_put before we decrement the number of in-progress bios. BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 11557f0067 P4D 11557f0067 PUD 0 Oops: 0002 [#1] PREEMPT SMP CPU: 0 PID: 73 Comm: kworker/0:1 Not tainted 6.1.0-rc3 #5 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 Workqueue: kdelayd flush_expired_bios [dm_delay] RIP: 0010:mempool_free+0x47/0x80 Code: 48 89 ef 5b 5d ff e0 f3 c3 48 89 f7 e8 32 45 3f 00 48 63 53 08 48 89 c6 3b 53 04 7d 2d 48 8b 43 10 8d 4a 01 48 89 df 89 4b 08 <48> 89 2c d0 e8 b0 45 3f 00 48 8d 7b 30 5b 5d 31 c9 ba 01 00 00 00 RSP: 0018:ffff88910036bda8 EFLAGS: 00010093 RAX: 0000000000000000 RBX: ffff8891037b65d8 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000202 RDI: ffff8891037b65d8 RBP: ffff8891447ba240 R08: 0000000000012908 R09: 00000000003d0900 R10: 0000000000000000 R11: 0000000000173544 R12: ffff889101a14000 R13: ffff8891562ac300 R14: ffff889102b41440 R15: ffffe8ffffa00d05 FS: 0000000000000000(0000) GS:ffff88942fa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000001102e99000 CR4: 00000000000006b0 Call Trace: <TASK> clone_endio+0xf4/0x1c0 [dm_mod] clone_endio+0xf4/0x1c0 [dm_mod] __submit_bio+0x76/0x120 submit_bio_noacct_nocheck+0xb6/0x2a0 flush_expired_bios+0x28/0x2f [dm_delay] process_one_work+0x1b4/0x300 worker_thread+0x45/0x3e0 ? rescuer_thread+0x380/0x380 kthread+0xc2/0x100 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x1f/0x30 </TASK> Modules linked in: brd dm_delay dm_raid dm_mod af_packet uvesafb cfbfillrect cfbimgblt cn cfbcopyarea fb font fbdev tun autofs4 binfmt_misc configfs ipv6 virtio_rng virtio_balloon rng_core virtio_net pcspkr net_failover failover qemu_fw_cfg button mousedev raid10 raid456 libcrc32c async_raid6_recov async_memcpy async_pq raid6_pq async_xor xor async_tx raid1 raid0 md_mod sd_mod t10_pi crc64_rocksoft crc64 virtio_scsi scsi_mod evdev psmouse bsg scsi_common [last unloaded: brd] CR2: 0000000000000000 ---[ end trace 0000000000000000 ]---

Timeline

Scores

EPSS (exploitation in 30 days)

0.16% · top 94% of all CVEs (7 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-476 NULL Pointer Dereference (opens in a new tab)All about CWE-476 and its CVEs

Affected products

• Linux · Linux

  • affected f8b58edf3acf0dcc186b8330939000ecf709368a – < 732cd66ec19a17f2b9183d7d5b7bdb9c39b0776e
  • affected f8b58edf3acf0dcc186b8330939000ecf709368a – < cf06b162f5b6337b688072a1a47941280b8f7110
  • affected f8b58edf3acf0dcc186b8330939000ecf709368a – < b5be563b4356b3089b3245d024cae3f248ba7090
  • affected f8b58edf3acf0dcc186b8330939000ecf709368a – < 384ef33d37cefb2ac539d44597d03f06c9b8975c
  • affected f8b58edf3acf0dcc186b8330939000ecf709368a – < ae7793027766491c5f8635b12d15a5940d3b8698
  • affected f8b58edf3acf0dcc186b8330939000ecf709368a – < 91bd504128a51776472445070e11a3b0f9348c90
  • affected f8b58edf3acf0dcc186b8330939000ecf709368a – < 842f222fc42a9239831e15b1fd49a51c546902cb
  • affected f8b58edf3acf0dcc186b8330939000ecf709368a – < 97ce99984be12b9acb49ddce0f5d8ebb037adbb6
  • affected f8b58edf3acf0dcc186b8330939000ecf709368a – < 341097ee53573e06ab9fc675d96a052385b851fa

• Linux · Linux

  • affected 2.6.13
  • unaffected < 2.6.13
  • unaffected 4.9.337 – ≤ 4.9.*
  • unaffected 4.14.303 – ≤ 4.14.*
  • unaffected 4.19.270 – ≤ 4.19.*
  • unaffected 5.4.229 – ≤ 5.4.*
  • unaffected 5.10.163 – ≤ 5.10.*
  • unaffected 5.15.87 – ≤ 5.15.*
  • unaffected 6.0.17 – ≤ 6.0.*
  • unaffected 6.1.3 – ≤ 6.1.*
  • unaffected 6.2 – ≤ *

References (9)

• https://git.kernel.org/stable/c/732cd66ec19a17f2b9183d7d5b7bdb9c39b0776e (opens in a new tab)
• https://git.kernel.org/stable/c/cf06b162f5b6337b688072a1a47941280b8f7110 (opens in a new tab)
• https://git.kernel.org/stable/c/b5be563b4356b3089b3245d024cae3f248ba7090 (opens in a new tab)
• https://git.kernel.org/stable/c/384ef33d37cefb2ac539d44597d03f06c9b8975c (opens in a new tab)
• https://git.kernel.org/stable/c/ae7793027766491c5f8635b12d15a5940d3b8698 (opens in a new tab)
• https://git.kernel.org/stable/c/91bd504128a51776472445070e11a3b0f9348c90 (opens in a new tab)
• https://git.kernel.org/stable/c/842f222fc42a9239831e15b1fd49a51c546902cb (opens in a new tab)
• https://git.kernel.org/stable/c/97ce99984be12b9acb49ddce0f5d8ebb037adbb6 (opens in a new tab)
• https://git.kernel.org/stable/c/341097ee53573e06ab9fc675d96a052385b851fa (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-2022-50381](https://trackcve.app/badge/CVE-2022-50381.svg)](https://trackcve.app/cve/CVE-2022-50381)

Record last updated 11 May 2026, 19:18 UTC.