CVE-2022-49722

In the Linux kernel, the following vulnerability has been resolved:

ice: Fix memory corruption in VF driver

Disable VFs RX/TX queues, when its 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 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

Weakness

The product writes data past the end, or before the beginning, of the intended buffer.

Affected Software

Potential Mitigations

• Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

• For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer.

• Be wary that a language’s interface to native code may still be subject to overflows, even if the language itself is theoretically safe.

• Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

• Examples include the Safe C String Library (SafeStr) by Messier and Viega [REF-57], and the Strsafe.h library from Microsoft [REF-56]. These libraries provide safer versions of overflow-prone string-handling functions.

• Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking.

• D3-SFCV (Stack Frame Canary Validation) from D3FEND [REF-1334] discusses canary-based detection in detail.

• Consider adhering to the following rules when allocating and managing an application’s memory:

• Run or compile the software using features or extensions that randomly arrange the positions of a program’s executable and libraries in memory. Because this makes the addresses unpredictable, it can prevent an attacker from reliably jumping to exploitable code.

• Examples include Address Space Layout Randomization (ASLR) [REF-58] [REF-60] and Position-Independent Executables (PIE) [REF-64]. Imported modules may be similarly realigned if their default memory addresses conflict with other modules, in a process known as “rebasing” (for Windows) and “prelinking” (for Linux) [REF-1332] using randomly generated addresses. ASLR for libraries cannot be used in conjunction with prelink since it would require relocating the libraries at run-time, defeating the whole purpose of prelinking.

• For more information on these techniques see D3-SAOR (Segment Address Offset Randomization) from D3FEND [REF-1335].

• Use a CPU and operating system that offers Data Execution Protection (using hardware NX or XD bits) or the equivalent techniques that simulate this feature in software, such as PaX [REF-60] [REF-61]. These techniques ensure that any instruction executed is exclusively at a memory address that is part of the code segment.

• For more information on these techniques see D3-PSEP (Process Segment Execution Prevention) from D3FEND [REF-1336].

References

• https://git.kernel.org/stable/c/1bb8253b1dd44cf004e12c333acc6f25ee286cf3
• https://git.kernel.org/stable/c/efe41860008e57fb6b69855b4b93fdf34bc42798