CVE-2022-49434: PCI: Avoid pci_dev_lock() AB/BA deadlock with sriov_numvfs_store()
Vulnerability summary
CVE-2022-49434 is a medium (CVSS 5.5) Improper Locking vulnerability in linux. EPSS estimates a 0.21% chance of exploitation in the next 30 days, higher than 12% of scored vulnerabilities.
Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 6 · Related 5Timeline
- 26-02-2025PublishedVulnerability first disclosed.
- 11-05-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: PCI: Avoid pci_dev_lock() AB/BA deadlock with sriov_numvfs_store() The sysfs sriov_numvfs_store() path acquires the device lock before the config space access lock: sriov_numvfs_store device_lock # A (1) acquire device lock sriov_configure vfio_pci_sriov_configure # (for example) vfio_pci_core_sriov_configure pci_disable_sriov sriov_disable pci_cfg_access_lock pci_wait_cfg # B (4) wait for dev->block_cfg_access == 0 Previously, pci_dev_lock() acquired the config space access lock before the device lock: pci_dev_lock pci_cfg_access_lock dev->block_cfg_access = 1 # B (2) set dev->block_cfg_access = 1 device_lock # A (3) wait for device lock Any path that uses pci_dev_lock(), e.g., pci_reset_function(), may deadlock with sriov_numvfs_store() if the operations occur in the sequence (1) (2) (3) (4). Avoid the deadlock by reversing the order in pci_dev_lock() so it acquires the device lock before the config space access lock, the same as the sriov_numvfs_store() path. [bhelgaas: combined and adapted commit log from Jay Zhou's independent subsequent posting: https://lore.kernel.org/r/20220404062539.1710-1-jianjay.zhou@huawei.com]
CVSS metrics
3 scores · 3 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.21%
Chance of exploitation in the next 30 days
Percentile
12%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.21% 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.
Ubuntu112 products
- linuxAll versions (No fix recorded) | < 4.15.0-192.203 | < 5.4.0-126.142 | < 5.15.0-47.51
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 4.15.0-1140.151 | < 5.4.0-1085.92 | < 5.15.0-1019.23
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 17530e71e0166a37f8e20a9b7bcf1d50ae3cff8e, < c3c6dc1853b8bf3c718f96fd8480a6eb09ba4831 | ≥ 17530e71e0166a37f8e20a9b7bcf1d50ae3cff8e, < aed6d4d519210c28817948f34c53b6e058e0456c | ≥ 17530e71e0166a37f8e20a9b7bcf1d50ae3cff8e, < c9a81f9ed6ae3554621d6a50220b1bc74b67d81e | ≥ 17530e71e0166a37f8e20a9b7bcf1d50ae3cff8e, < eff3587b9c01439b738298475e555c028ac9f55e | ≥ 17530e71e0166a37f8e20a9b7bcf1d50ae3cff8e, < 2cdd5284035322795b0964f899eefba254cfe483 | ≥ 17530e71e0166a37f8e20a9b7bcf1d50ae3cff8e, < ea047f51172aa68841adef7f52d375002438b8f0 | ≥ 17530e71e0166a37f8e20a9b7bcf1d50ae3cff8e, < 59ea6b3ae51df7cd6bfd84c9c0030609b9315622 | ≥ 17530e71e0166a37f8e20a9b7bcf1d50ae3cff8e, < a91ee0e9fca9d7501286cfbced9b30a33e52740a | 4.13
- linux_kernel< 4.9.318 | ≥ 4.10, < 4.14.283 | ≥ 4.15, < 4.19.247 | ≥ 4.20, < 5.4.198 | ≥ 5.5, < 5.10.121 | ≥ 5.11, < 5.15.46 | ≥ 5.16, < 5.17.14 | ≥ 5.18, < 5.18.3
Debian1 product
- linux< 5.18.5-1
3 vendors · 115 products
