CVE-2022-50488
block, bfq: fix possible uaf for 'bfqq->bic'
Description
In the Linux kernel, the following vulnerability has been resolved: block, bfq: fix possible uaf for 'bfqq->bic' Our test report a uaf for 'bfqq->bic' in 5.10: ================================================================== BUG: KASAN: use-after-free in bfq_select_queue+0x378/0xa30 CPU: 6 PID: 2318352 Comm: fsstress Kdump: loaded Not tainted 5.10.0-60.18.0.50.h602.kasan.eulerosv2r11.x86_64 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58-20220320_160524-szxrtosci10000 04/01/2014 Call Trace: bfq_select_queue+0x378/0xa30 bfq_dispatch_request+0xe8/0x130 blk_mq_do_dispatch_sched+0x62/0xb0 __blk_mq_sched_dispatch_requests+0x215/0x2a0 blk_mq_sched_dispatch_requests+0x8f/0xd0 __blk_mq_run_hw_queue+0x98/0x180 __blk_mq_delay_run_hw_queue+0x22b/0x240 blk_mq_run_hw_queue+0xe3/0x190 blk_mq_sched_insert_requests+0x107/0x200 blk_mq_flush_plug_list+0x26e/0x3c0 blk_finish_plug+0x63/0x90 __iomap_dio_rw+0x7b5/0x910 iomap_dio_rw+0x36/0x80 ext4_dio_read_iter+0x146/0x190 [ext4] ext4_file_read_iter+0x1e2/0x230 [ext4] new_sync_read+0x29f/0x400 vfs_read+0x24e/0x2d0 ksys_read+0xd5/0x1b0 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x61/0xc6 Commit 3bc5e683c67d ("bfq: Split shared queues on move between cgroups") changes that move process to a new cgroup will allocate a new bfqq to use, however, the old bfqq and new bfqq can point to the same bic: 1) Initial state, two process with io in the same cgroup. Process 1 Process 2 (BIC1) (BIC2) | Λ | Λ | | | | V | V | bfqq1 bfqq2 2) bfqq1 is merged to bfqq2. Process 1 Process 2 (BIC1) (BIC2) | | \-------------\| V bfqq1 bfqq2(coop) 3) Process 1 exit, then issue new io(denoce IOA) from Process 2. (BIC2) | Λ | | V | bfqq2(coop) 4) Before IOA is completed, move Process 2 to another cgroup and issue io. Process 2 (BIC2) Λ |\--------------\ | V bfqq2 bfqq3 Now that BIC2 points to bfqq3, while bfqq2 and bfqq3 both point to BIC2. If all the requests are completed, and Process 2 exit, BIC2 will be freed while there is no guarantee that bfqq2 will be freed before BIC2. Fix the problem by clearing bfqq->bic while bfqq is detached from bic.
INFO
Published Date :
Oct. 4, 2025, 4:15 p.m.
Last Modified :
Jan. 26, 2026, 7:49 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Apply the kernel patch for the identified issue.
- Update the Linux kernel to a patched version.
- Rebuild and deploy the kernel.
- Verify the fix in the updated kernel.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2022-50488.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2022-50488 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2022-50488
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2022-50488 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2022-50488 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jan. 26, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-416 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.1 up to (excluding) 6.1.2 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.17.14 up to (excluding) 5.18 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.4.198 up to (excluding) 5.5 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.10.121 up to (excluding) 5.10.175 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.15.46 up to (excluding) 5.15.86 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.18.3 up to (excluding) 6.0.16 Added Reference Type kernel.org: https://git.kernel.org/stable/c/094f3d9314d67691cb21ba091c1b528f6e3c4893 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/5533742c7cb1bc9b1f0bf401cc397d44a3a9e07a Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/64dc8c732f5c2b406cc752e6aaa1bd5471159cab Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/761564d93c8265f65543acf0a576b32d66bfa26a Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/b22fd72bfebda3956efc4431b60ddfc0a51e03e0 Types: Patch -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Oct. 04, 2025
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: block, bfq: fix possible uaf for 'bfqq->bic' Our test report a uaf for 'bfqq->bic' in 5.10: ================================================================== BUG: KASAN: use-after-free in bfq_select_queue+0x378/0xa30 CPU: 6 PID: 2318352 Comm: fsstress Kdump: loaded Not tainted 5.10.0-60.18.0.50.h602.kasan.eulerosv2r11.x86_64 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58-20220320_160524-szxrtosci10000 04/01/2014 Call Trace: bfq_select_queue+0x378/0xa30 bfq_dispatch_request+0xe8/0x130 blk_mq_do_dispatch_sched+0x62/0xb0 __blk_mq_sched_dispatch_requests+0x215/0x2a0 blk_mq_sched_dispatch_requests+0x8f/0xd0 __blk_mq_run_hw_queue+0x98/0x180 __blk_mq_delay_run_hw_queue+0x22b/0x240 blk_mq_run_hw_queue+0xe3/0x190 blk_mq_sched_insert_requests+0x107/0x200 blk_mq_flush_plug_list+0x26e/0x3c0 blk_finish_plug+0x63/0x90 __iomap_dio_rw+0x7b5/0x910 iomap_dio_rw+0x36/0x80 ext4_dio_read_iter+0x146/0x190 [ext4] ext4_file_read_iter+0x1e2/0x230 [ext4] new_sync_read+0x29f/0x400 vfs_read+0x24e/0x2d0 ksys_read+0xd5/0x1b0 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x61/0xc6 Commit 3bc5e683c67d ("bfq: Split shared queues on move between cgroups") changes that move process to a new cgroup will allocate a new bfqq to use, however, the old bfqq and new bfqq can point to the same bic: 1) Initial state, two process with io in the same cgroup. Process 1 Process 2 (BIC1) (BIC2) | Λ | Λ | | | | V | V | bfqq1 bfqq2 2) bfqq1 is merged to bfqq2. Process 1 Process 2 (BIC1) (BIC2) | | \-------------\| V bfqq1 bfqq2(coop) 3) Process 1 exit, then issue new io(denoce IOA) from Process 2. (BIC2) | Λ | | V | bfqq2(coop) 4) Before IOA is completed, move Process 2 to another cgroup and issue io. Process 2 (BIC2) Λ |\--------------\ | V bfqq2 bfqq3 Now that BIC2 points to bfqq3, while bfqq2 and bfqq3 both point to BIC2. If all the requests are completed, and Process 2 exit, BIC2 will be freed while there is no guarantee that bfqq2 will be freed before BIC2. Fix the problem by clearing bfqq->bic while bfqq is detached from bic. Added Reference https://git.kernel.org/stable/c/094f3d9314d67691cb21ba091c1b528f6e3c4893 Added Reference https://git.kernel.org/stable/c/5533742c7cb1bc9b1f0bf401cc397d44a3a9e07a Added Reference https://git.kernel.org/stable/c/64dc8c732f5c2b406cc752e6aaa1bd5471159cab Added Reference https://git.kernel.org/stable/c/761564d93c8265f65543acf0a576b32d66bfa26a Added Reference https://git.kernel.org/stable/c/b22fd72bfebda3956efc4431b60ddfc0a51e03e0