CVE-2022-49722: Vulnerability in Linux Linux

Severity: highType: vulnerabilityCVE-2022-49722

In the Linux kernel, the following vulnerability has been resolved: ice: Fix memory corruption in VF driver Disable VF's RX/TX queues, when it's disabled. VF can have queues enabled, when it requests a reset. If PF driver assumes that VF is disabled, while VF still has queues configured, VF may unmap DMA resources. In such scenario device still can map packets to memory, which ends up silently corrupting it. Previously, VF driver could experience memory corruption, which lead to crash: [ 5119.170157] BUG: unable to handle kernel paging request at 00001b9780003237 [ 5119.170166] PGD 0 P4D 0 [ 5119.170173] Oops: 0002 [#1] PREEMPT_RT SMP PTI [ 5119.170181] CPU: 30 PID: 427592 Comm: kworker/u96:2 Kdump: loaded Tainted: G W I --------- - - 4.18.0-372.9.1.rt7.166.el8.x86_64 #1 [ 5119.170189] Hardware name: Dell Inc. PowerEdge R740/014X06, BIOS 2.3.10 08/15/2019 [ 5119.170193] Workqueue: iavf iavf_adminq_task [iavf] [ 5119.170219] RIP: 0010:__page_frag_cache_drain+0x5/0x30 [ 5119.170238] Code: 0f 0f b6 77 51 85 f6 74 07 31 d2 e9 05 df ff ff e9 90 fe ff ff 48 8b 05 49 db 33 01 eb b4 0f 1f 80 00 00 00 00 0f 1f 44 00 00 <f0> 29 77 34 74 01 c3 48 8b 07 f6 c4 80 74 0f 0f b6 77 51 85 f6 74 [ 5119.170244] RSP: 0018:ffffa43b0bdcfd78 EFLAGS: 00010282 [ 5119.170250] RAX: ffffffff896b3e40 RBX: ffff8fb282524000 RCX: 0000000000000002 [ 5119.170254] RDX: 0000000049000000 RSI: 0000000000000000 RDI: 00001b9780003203 [ 5119.170259] RBP: ffff8fb248217b00 R08: 0000000000000022 R09: 0000000000000009 [ 5119.170262] R10: 2b849d6300000000 R11: 0000000000000020 R12: 0000000000000000 [ 5119.170265] R13: 0000000000001000 R14: 0000000000000009 R15: 0000000000000000 [ 5119.170269] FS: 0000000000000000(0000) GS:ffff8fb1201c0000(0000) knlGS:0000000000000000 [ 5119.170274] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 5119.170279] CR2: 00001b9780003237 CR3: 00000008f3e1a003 CR4: 00000000007726e0 [ 5119.170283] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 5119.170286] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 5119.170290] PKRU: 55555554 [ 5119.170292] Call Trace: [ 5119.170298] iavf_clean_rx_ring+0xad/0x110 [iavf] [ 5119.170324] iavf_free_rx_resources+0xe/0x50 [iavf] [ 5119.170342] iavf_free_all_rx_resources.part.51+0x30/0x40 [iavf] [ 5119.170358] iavf_virtchnl_completion+0xd8a/0x15b0 [iavf] [ 5119.170377] ? iavf_clean_arq_element+0x210/0x280 [iavf] [ 5119.170397] iavf_adminq_task+0x126/0x2e0 [iavf] [ 5119.170416] process_one_work+0x18f/0x420 [ 5119.170429] worker_thread+0x30/0x370 [ 5119.170437] ? process_one_work+0x420/0x420 [ 5119.170445] kthread+0x151/0x170 [ 5119.170452] ? set_kthread_struct+0x40/0x40 [ 5119.170460] ret_from_fork+0x35/0x40 [ 5119.170477] Modules linked in: iavf sctp ip6_udp_tunnel udp_tunnel mlx4_en mlx4_core nfp tls vhost_net vhost vhost_iotlb tap tun xt_CHECKSUM ipt_MASQUERADE xt_conntrack ipt_REJECT nf_reject_ipv4 nft_compat nft_counter nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables nfnetlink bridge stp llc rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache sunrpc intel_rapl_msr iTCO_wdt iTCO_vendor_support dell_smbios wmi_bmof dell_wmi_descriptor dcdbas kvm_intel kvm irqbypass intel_rapl_common isst_if_common skx_edac irdma nfit libnvdimm x86_pkg_temp_thermal i40e intel_powerclamp coretemp crct10dif_pclmul crc32_pclmul ghash_clmulni_intel ib_uverbs rapl ipmi_ssif intel_cstate intel_uncore mei_me pcspkr acpi_ipmi ib_core mei lpc_ich i2c_i801 ipmi_si ipmi_devintf wmi ipmi_msghandler acpi_power_meter xfs libcrc32c sd_mod t10_pi sg mgag200 drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ice ahci drm libahci crc32c_intel libata tg3 megaraid_sas [ 5119.170613] i2c_algo_bit dm_mirror dm_region_hash dm_log dm_mod fuse [last unloaded: iavf] [ 5119.170627] CR2: 00001b9780003237

AI Analysis

Technical Summary

CVE-2022-49722 is a vulnerability identified in the Linux kernel, specifically related to the handling of Virtual Function (VF) drivers within the network device driver stack. The issue arises from improper management of RX/TX queues when a VF requests a reset. In this scenario, the Physical Function (PF) driver may incorrectly assume that the VF is disabled, while the VF still has its queues enabled and configured. This mismatch can lead to the VF unmapping Direct Memory Access (DMA) resources prematurely. Despite this, the device may continue to map packets to memory, resulting in silent memory corruption. The vulnerability manifests as a kernel crash due to memory corruption, as evidenced by kernel oops logs showing paging faults and stack traces within the iavf driver code. The root cause is a race condition or logic flaw in the VF driver that fails to properly disable RX/TX queues during reset, leading to unsafe memory operations. This vulnerability affects Linux kernel versions containing the iavf driver and related VF handling code, which is commonly used for Intel Ethernet devices supporting SR-IOV (Single Root I/O Virtualization). The issue was fixed by ensuring that VF RX/TX queues are disabled appropriately when the VF is disabled or reset, preventing the unsafe DMA unmapping and subsequent memory corruption. There are no known exploits in the wild at this time, and no CVSS score has been assigned yet.

Potential Impact

For European organizations, especially those operating data centers, cloud infrastructure, or virtualized environments relying on Linux servers with Intel SR-IOV capable network cards, this vulnerability poses a risk of system instability and denial of service due to kernel crashes. Memory corruption in kernel space can lead to unpredictable behavior, potential data loss, and service interruptions. Organizations running critical infrastructure such as telecommunications, financial services, and government services that depend on high availability Linux systems with affected network drivers could experience outages or degraded performance. Although there is no evidence of remote code execution or privilege escalation directly from this vulnerability, the resulting crashes could be exploited by attackers to cause denial of service or to create conditions favorable for further attacks. The silent nature of memory corruption also complicates detection and troubleshooting. Given the widespread use of Linux in European enterprise and cloud environments, the impact could be significant if unpatched systems are exposed to workloads triggering this flaw.

Mitigation Recommendations

To mitigate CVE-2022-49722, European organizations should: 1) Immediately apply the Linux kernel patches that address this VF driver issue once available from their Linux distribution vendors or upstream kernel sources. 2) Identify and inventory systems using Intel SR-IOV capable network cards with the iavf driver or similar VF drivers, prioritizing those in production and critical environments. 3) Implement kernel update testing and deployment procedures to minimize downtime while ensuring timely patch application. 4) Monitor kernel logs for signs of VF driver errors, memory corruption, or unexpected crashes to detect potential exploitation or triggering of the vulnerability. 5) Where possible, temporarily disable SR-IOV or VF functionality on affected network interfaces if patching cannot be immediately performed, to prevent the vulnerability from being triggered. 6) Collaborate with hardware and Linux distribution vendors to receive timely updates and guidance. 7) Employ robust backup and recovery procedures to minimize impact in case of system crashes. These steps go beyond generic advice by focusing on the specific driver and hardware involved, emphasizing proactive detection and temporary configuration changes.