CVE-2022-48674: erofs: fix pcluster use-after-free on UP platforms
Vulnerability summary
CVE-2022-48674 is a high (CVSS 7.8) Use After Free vulnerability in linux. EPSS estimates a 0.23% chance of exploitation in the next 30 days, higher than 14.4% of scored vulnerabilities.
Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 9 · Related 9Timeline
- 03-05-2024PublishedVulnerability first disclosed.
- 05-08-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: erofs: fix pcluster use-after-free on UP platforms During stress testing with CONFIG_SMP disabled, KASAN reports as below: ================================================================== BUG: KASAN: use-after-free in __mutex_lock+0xe5/0xc30 Read of size 8 at addr ffff8881094223f8 by task stress/7789 CPU: 0 PID: 7789 Comm: stress Not tainted 6.0.0-rc1-00002-g0d53d2e882f9 #3 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 Call Trace: <TASK> .. __mutex_lock+0xe5/0xc30 .. z_erofs_do_read_page+0x8ce/0x1560 .. z_erofs_readahead+0x31c/0x580 .. Freed by task 7787 kasan_save_stack+0x1e/0x40 kasan_set_track+0x20/0x30 kasan_set_free_info+0x20/0x40 __kasan_slab_free+0x10c/0x190 kmem_cache_free+0xed/0x380 rcu_core+0x3d5/0xc90 __do_softirq+0x12d/0x389 Last potentially related work creation: kasan_save_stack+0x1e/0x40 __kasan_record_aux_stack+0x97/0xb0 call_rcu+0x3d/0x3f0 erofs_shrink_workstation+0x11f/0x210 erofs_shrink_scan+0xdc/0x170 shrink_slab.constprop.0+0x296/0x530 drop_slab+0x1c/0x70 drop_caches_sysctl_handler+0x70/0x80 proc_sys_call_handler+0x20a/0x2f0 vfs_write+0x555/0x6c0 ksys_write+0xbe/0x160 do_syscall_64+0x3b/0x90 The root cause is that erofs_workgroup_unfreeze() doesn't reset to orig_val thus it causes a race that the pcluster reuses unexpectedly before freeing. Since UP platforms are quite rare now, such path becomes unnecessary. Let's drop such specific-designed path directly instead.
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- NVDNIST7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.23%
Chance of exploitation in the next 30 days
Percentile
14%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.23% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu98 products
- linux< 5.4.0-192.212 | < 5.15.0-57.63
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 5.4.0-1130.140 | < 5.15.0-1027.31
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 73f5c66df3e26ab750cefcb9a3e08c71c9f79cad, < 8ddd001cef5e82d19192e6861068463ecca5f556 | ≥ 73f5c66df3e26ab750cefcb9a3e08c71c9f79cad, < 94c34faaafe7b55adc2d8d881db195b646959b9e | ≥ 73f5c66df3e26ab750cefcb9a3e08c71c9f79cad, < 2f44013e39984c127c6efedf70e6b5f4e9dcf315 | 08ec9e6892cc792d7f8fe4d13bd8a0e91fb23488 | 78c46113413bea1cc345757112aa2642e0f66de5 | ≥ 4.19.26, < 4.20 | ≥ 4.20.13, < 4.21 | 5.0
- linux_kernel≥ 4.19.26, < 4.20 | ≥ 4.20.13, < 5.15.68 | ≥ 5.16, < 5.19.9 | 6.0:rc1 | 6.0:rc2 | 6.0:rc3 | 6.0:rc4
Debian1 product
- linux< 5.19.11-1
3 vendors · 101 products
