CVE-2024-46765
Description
From CVE.org
In the Linux kernel, the following vulnerability has been resolved: ice: protect XDP configuration with a mutex The main threat to data consistency in ice_xdp() is a possible asynchronous PF reset. It can be triggered by a user or by TX timeout handler. XDP setup and PF reset code access the same resources in the following sections: * ice_vsi_close() in ice_prepare_for_reset() - already rtnl-locked * ice_vsi_rebuild() for the PF VSI - not protected * ice_vsi_open() - already rtnl-locked With an unfortunate timing, such accesses can result in a crash such as the one below: [ +1.999878] ice 0000:b1:00.0: Registered XDP mem model MEM_TYPE_XSK_BUFF_POOL on Rx ring 14 [ +2.002992] ice 0000:b1:00.0: Registered XDP mem model MEM_TYPE_XSK_BUFF_POOL on Rx ring 18 [Mar15 18:17] ice 0000:b1:00.0 ens801f0np0: NETDEV WATCHDOG: CPU: 38: transmit queue 14 timed out 80692736 ms [ +0.000093] ice 0000:b1:00.0 ens801f0np0: tx_timeout: VSI_num: 6, Q 14, NTC: 0x0, HW_HEAD: 0x0, NTU: 0x0, INT: 0x4000001 [ +0.000012] ice 0000:b1:00.0 ens801f0np0: tx_timeout recovery level 1, txqueue 14 [ +0.394718] ice 0000:b1:00.0: PTP reset successful [ +0.006184] BUG: kernel NULL pointer dereference, address: 0000000000000098 [ +0.000045] #PF: supervisor read access in kernel mode [ +0.000023] #PF: error_code(0x0000) - not-present page [ +0.000023] PGD 0 P4D 0 [ +0.000018] Oops: 0000 [#1] PREEMPT SMP NOPTI [ +0.000023] CPU: 38 PID: 7540 Comm: kworker/38:1 Not tainted 6.8.0-rc7 #1 [ +0.000031] Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0014.082620210524 08/26/2021 [ +0.000036] Workqueue: ice ice_service_task [ice] [ +0.000183] RIP: 0010:ice_clean_tx_ring+0xa/0xd0 [ice] [...] [ +0.000013] Call Trace: [ +0.000016] <TASK> [ +0.000014] ? __die+0x1f/0x70 [ +0.000029] ? page_fault_oops+0x171/0x4f0 [ +0.000029] ? schedule+0x3b/0xd0 [ +0.000027] ? exc_page_fault+0x7b/0x180 [ +0.000022] ? asm_exc_page_fault+0x22/0x30 [ +0.000031] ? ice_clean_tx_ring+0xa/0xd0 [ice] [ +0.000194] ice_free_tx_ring+0xe/0x60 [ice] [ +0.000186] ice_destroy_xdp_rings+0x157/0x310 [ice] [ +0.000151] ice_vsi_decfg+0x53/0xe0 [ice] [ +0.000180] ice_vsi_rebuild+0x239/0x540 [ice] [ +0.000186] ice_vsi_rebuild_by_type+0x76/0x180 [ice] [ +0.000145] ice_rebuild+0x18c/0x840 [ice] [ +0.000145] ? delay_tsc+0x4a/0xc0 [ +0.000022] ? delay_tsc+0x92/0xc0 [ +0.000020] ice_do_reset+0x140/0x180 [ice] [ +0.000886] ice_service_task+0x404/0x1030 [ice] [ +0.000824] process_one_work+0x171/0x340 [ +0.000685] worker_thread+0x277/0x3a0 [ +0.000675] ? preempt_count_add+0x6a/0xa0 [ +0.000677] ? _raw_spin_lock_irqsave+0x23/0x50 [ +0.000679] ? __pfx_worker_thread+0x10/0x10 [ +0.000653] kthread+0xf0/0x120 [ +0.000635] ? __pfx_kthread+0x10/0x10 [ +0.000616] ret_from_fork+0x2d/0x50 [ +0.000612] ? __pfx_kthread+0x10/0x10 [ +0.000604] ret_from_fork_asm+0x1b/0x30 [ +0.000604] </TASK> The previous way of handling this through returning -EBUSY is not viable, particularly when destroying AF_XDP socket, because the kernel proceeds with removal anyway. There is plenty of code between those calls and there is no need to create a large critical section that covers all of them, same as there is no need to protect ice_vsi_rebuild() with rtnl_lock(). Add xdp_state_lock mutex to protect ice_vsi_rebuild() and ice_xdp(). Leaving unprotected sections in between would result in two states that have to be considered: 1. when the VSI is closed, but not yet rebuild 2. when VSI is already rebuild, but not yet open The latter case is actually already handled through !netif_running() case, we just need to adjust flag checking a little. The former one is not as trivial, because between ice_vsi_close() and ice_vsi_rebuild(), a lot of hardware interaction happens, this can make adding/deleting rings exit with an error. Luckily, VSI rebuild is pending and can apply new configuration for us in a managed fashion. Therefore, add an additional VSI state flag ICE_VSI_REBUILD_PENDING to indicate that ice_x ---truncated---
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.7 | 5.5 | 7.8 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | High | Low | Low |
| Privileges Required | Low | Low | Low |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | None | High |
| Integrity Impact | None | None | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
When a race condition makes it possible to bypass a resource cleanup routine or trigger multiple initialization routines, it may lead to resource exhaustion.
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Instability
When a race condition allows multiple control flows to access a resource simultaneously, it might lead the product(s) into unexpected states, possibly resulting in a crash.
Confidentiality,Integrity
Technical Impact: Read Files or Directories; Read Application Data
When a race condition is combined with predictable resource names and loose permissions, it may be possible for an attacker to overwrite or access confidential data (CWE-59).
Access Control
Technical Impact: Execute Unauthorized Code or Commands; Gain Privileges or Assume Identity; Bypass Protection Mechanism
This can have security implications when the expected synchronization is in security-critical code, such as recording whether a user is authenticated or modifying important state information that should not be influenced by an outsider.
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