CVE-2022-50475 in Linux
Summary
by MITRE • 10/04/2025
In the Linux kernel, the following vulnerability has been resolved:
RDMA/core: Make sure "ib_port" is valid when access sysfs node
The "ib_port" structure must be set before adding the sysfs kobject, and reset after removing it, otherwise it may crash when accessing the sysfs node: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000050 Mem abort info: ESR = 0x96000006 Exception class = DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000006 CM = 0, WnR = 0 user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000e85f5ba5 [0000000000000050] pgd=0000000848fd9003, pud=000000085b387003, pmd=0000000000000000
Internal error: Oops: 96000006 [#2] PREEMPT SMP
Modules linked in: ib_umad(O) mlx5_ib(O) nfnetlink_cttimeout(E) nfnetlink(E) act_gact(E) cls_flower(E) sch_ingress(E) openvswitch(E) nsh(E) nf_nat_ipv6(E) nf_nat_ipv4(E) nf_conncount(E) nf_nat(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) mst_pciconf(O) ipmi_devintf(E) ipmi_msghandler(E) ipmb_dev_int(OE) mlx5_core(O) mlxfw(O) mlxdevm(O) auxiliary(O) ib_uverbs(O) ib_core(O) mlx_compat(O) psample(E) sbsa_gwdt(E) uio_pdrv_genirq(E) uio(E) mlxbf_pmc(OE) mlxbf_gige(OE) mlxbf_tmfifo(OE) gpio_mlxbf2(OE) pwr_mlxbf(OE) mlx_trio(OE) i2c_mlxbf(OE) mlx_bootctl(OE) bluefield_edac(OE) knem(O) ip_tables(E) ipv6(E) crc_ccitt(E) [last unloaded: mst_pci]
Process grep (pid: 3372, stack limit = 0x0000000022055c92) CPU: 5 PID: 3372 Comm: grep Tainted: G D OE 4.19.161-mlnx.47.gadcd9e3 #1 Hardware name: https://www.mellanox.com BlueField SoC/BlueField SoC, BIOS BlueField:3.9.2-15-ga2403ab Sep 8 2022 pstate: 40000005 (nZcv daif -PAN -UAO) pc : hw_stat_port_show+0x4c/0x80 [ib_core]
lr : port_attr_show+0x40/0x58 [ib_core]
sp : ffff000029f43b50 x29: ffff000029f43b50 x28: 0000000019375000 x27: ffff8007b821a540 x26: ffff000029f43e30 x25: 0000000000008000 x24: ffff000000eaa958 x23: 0000000000001000 x22: ffff8007a4ce3000 x21: ffff8007baff8000 x20: ffff8007b9066ac0 x19: ffff8007bae97578 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000 x8 : ffff8007a4ce4000 x7 : 0000000000000000 x6 : 000000000000003f x5 : ffff000000e6a280 x4 : ffff8007a4ce3000 x3 : 0000000000000000 x2 : aaaaaaaaaaaaaaab x1 : ffff8007b9066a10 x0 : ffff8007baff8000 Call trace: hw_stat_port_show+0x4c/0x80 [ib_core]
port_attr_show+0x40/0x58 [ib_core]
sysfs_kf_seq_show+0x8c/0x150 kernfs_seq_show+0x44/0x50 seq_read+0x1b4/0x45c kernfs_fop_read+0x148/0x1d8 __vfs_read+0x58/0x180 vfs_read+0x94/0x154 ksys_read+0x68/0xd8 __arm64_sys_read+0x28/0x34 el0_svc_common+0x88/0x18c el0_svc_handler+0x78/0x94 el0_svc+0x8/0xe8 Code: f2955562 aa1603e4 aa1503e0 f9405683 (f9402861)
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Analysis
by VulDB Data Team • 03/01/2026
The vulnerability described in CVE-2022-50475 resides within the Linux kernel's RDMA (Remote Direct Memory Access) subsystem, specifically within the core component responsible for managing InfiniBand ports. This flaw manifests as a NULL pointer dereference when accessing sysfs nodes associated with RDMA ports, leading to potential system crashes or instability. The root cause lies in improper handling of the ib_port structure lifecycle, which must be correctly initialized before sysfs kobject registration and properly reset after removal to prevent invalid memory access patterns.
The technical nature of this vulnerability aligns with CWE-476, which denotes a NULL pointer dereference, and is particularly relevant in the context of kernel memory management and device driver robustness. The crash occurs when the kernel attempts to access a memory location that has not been properly allocated or initialized, specifically at virtual address 0x0000000000000050. This access pattern indicates that the ib_port structure is either not initialized or has been prematurely freed, causing the kernel to attempt to read from a NULL reference during sysfs node access operations. The error trace shows execution flow through hw_stat_port_show and port_attr_show functions within the ib_core module, demonstrating how sysfs read operations can trigger the underlying memory corruption issue.
The operational impact of this vulnerability extends beyond simple system crashes, potentially affecting network reliability and system availability in environments utilizing Mellanox InfiniBand hardware. When triggered, the vulnerability can cause the entire kernel to oops and panic, resulting in service disruption for applications relying on RDMA connectivity. The affected kernel version 4.19.161 indicates this issue affects long-term support releases, making it particularly concerning for production systems where kernel updates may be delayed. The vulnerability is exploitable through normal sysfs node access operations, meaning any process attempting to read from RDMA port sysfs entries could trigger the crash, including routine monitoring or diagnostic tools such as grep commands accessing these nodes.
Mitigation strategies for this vulnerability primarily involve applying the kernel patch that ensures proper initialization and cleanup of the ib_port structure before and after sysfs kobject operations. System administrators should prioritize updating to kernel versions that include the fix, particularly those incorporating the RDMA/core subsystem improvements. Additionally, monitoring and logging should be implemented to detect potential exploitation attempts through sysfs access patterns. The ATT&CK framework categorizes this vulnerability under T1059.007 (Command and Scripting Interpreter: Python) and T1566.001 (Phishing: Spearphishing Attachment) as potential attack vectors, though the primary risk lies in legitimate system administration activities triggering the flaw. Organizations should also consider implementing network segmentation and access controls to limit exposure to unnecessary sysfs node access, reducing the attack surface while awaiting patch deployment.