CVE-2023-52782: Vulnerability in Linux Linux

Severity: highType: vulnerabilityCVE-2023-52782

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Track xmit submission to PTP WQ after populating metadata map Ensure the skb is available in metadata mapping to skbs before tracking the metadata index for detecting undelivered CQEs. If the metadata index is put in the tracking list before putting the skb in the map, the metadata index might be used for detecting undelivered CQEs before the relevant skb is available in the map, which can lead to a null-ptr-deref. Log: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] CPU: 0 PID: 1243 Comm: kworker/0:2 Not tainted 6.6.0-rc4+ #108 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Workqueue: events mlx5e_rx_dim_work [mlx5_core] RIP: 0010:mlx5e_ptp_napi_poll+0x9a4/0x2290 [mlx5_core] Code: 8c 24 38 cc ff ff 4c 8d 3c c1 4c 89 f9 48 c1 e9 03 42 80 3c 31 00 0f 85 97 0f 00 00 4d 8b 3f 49 8d 7f 28 48 89 f9 48 c1 e9 03 <42> 80 3c 31 00 0f 85 8b 0f 00 00 49 8b 47 28 48 85 c0 0f 84 05 07 RSP: 0018:ffff8884d3c09c88 EFLAGS: 00010206 RAX: 0000000000000069 RBX: ffff8881160349d8 RCX: 0000000000000005 RDX: ffffed10218f48cf RSI: 0000000000000004 RDI: 0000000000000028 RBP: ffff888122707700 R08: 0000000000000001 R09: ffffed109a781383 R10: 0000000000000003 R11: 0000000000000003 R12: ffff88810c7a7a40 R13: ffff888122707700 R14: dffffc0000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8884d3c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4f878dd6e0 CR3: 000000014d108002 CR4: 0000000000370eb0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> ? die_addr+0x3c/0xa0 ? exc_general_protection+0x144/0x210 ? asm_exc_general_protection+0x22/0x30 ? mlx5e_ptp_napi_poll+0x9a4/0x2290 [mlx5_core] ? mlx5e_ptp_napi_poll+0x8f6/0x2290 [mlx5_core] __napi_poll.constprop.0+0xa4/0x580 net_rx_action+0x460/0xb80 ? _raw_spin_unlock_irqrestore+0x32/0x60 ? __napi_poll.constprop.0+0x580/0x580 ? tasklet_action_common.isra.0+0x2ef/0x760 __do_softirq+0x26c/0x827 irq_exit_rcu+0xc2/0x100 common_interrupt+0x7f/0xa0 </IRQ> <TASK> asm_common_interrupt+0x22/0x40 RIP: 0010:__kmem_cache_alloc_node+0xb/0x330 Code: 41 5d 41 5e 41 5f c3 8b 44 24 14 8b 4c 24 10 09 c8 eb d5 e8 b7 43 ca 01 0f 1f 80 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 57 <41> 56 41 89 d6 41 55 41 89 f5 41 54 49 89 fc 53 48 83 e4 f0 48 83 RSP: 0018:ffff88812c4079c0 EFLAGS: 00000246 RAX: 1ffffffff083c7fe RBX: ffff888100042dc0 RCX: 0000000000000218 RDX: 00000000ffffffff RSI: 0000000000000dc0 RDI: ffff888100042dc0 RBP: ffff88812c4079c8 R08: ffffffffa0289f96 R09: ffffed1025880ea9 R10: ffff888138839f80 R11: 0000000000000002 R12: 0000000000000dc0 R13: 0000000000000100 R14: 000000000000008c R15: ffff8881271fc450 ? cmd_exec+0x796/0x2200 [mlx5_core] kmalloc_trace+0x26/0xc0 cmd_exec+0x796/0x2200 [mlx5_core] mlx5_cmd_do+0x22/0xc0 [mlx5_core] mlx5_cmd_exec+0x17/0x30 [mlx5_core] mlx5_core_modify_cq_moderation+0x139/0x1b0 [mlx5_core] ? mlx5_add_cq_to_tasklet+0x280/0x280 [mlx5_core] ? lockdep_set_lock_cmp_fn+0x190/0x190 ? process_one_work+0x659/0x1220 mlx5e_rx_dim_work+0x9d/0x100 [mlx5_core] process_one_work+0x730/0x1220 ? lockdep_hardirqs_on_prepare+0x400/0x400 ? max_active_store+0xf0/0xf0 ? assign_work+0x168/0x240 worker_thread+0x70f/0x12d0 ? __kthread_parkme+0xd1/0x1d0 ? process_one_work+0x1220/0x1220 kthread+0x2d9/0x3b0 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x2d/0x70 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork_as ---truncated---

AI Analysis

Technical Summary

CVE-2023-52782 is a vulnerability identified in the Linux kernel, specifically within the mlx5e network driver component responsible for handling Mellanox network devices. The issue arises in the tracking of transmit (xmit) submissions to the Precision Time Protocol (PTP) Work Queue (WQ) after populating the metadata map. The vulnerability is due to a race condition or ordering flaw where the metadata index used to detect undelivered Completion Queue Entries (CQEs) is placed in the tracking list before the corresponding socket buffer (skb) is available in the metadata map. This premature tracking can lead to attempts to access the skb before it is mapped, resulting in a null pointer dereference (null-ptr-deref) and causing a general protection fault in the kernel. The provided kernel log snippet shows a general protection fault triggered by a null pointer dereference during the mlx5e_ptp_napi_poll function execution, which is part of the mlx5_core driver. This fault leads to a kernel crash (panic) or instability, impacting system availability. The vulnerability affects Linux kernel versions including those identified by specific commit hashes (e.g., e729382c297e2c492ff2a260aa1f23183eadae2e). No public exploits are known at this time, and no CVSS score has been assigned. The root cause is a synchronization issue in the network driver code that mishandles the lifecycle of skb metadata tracking, leading to unsafe memory access. This flaw could be triggered by network traffic processed by the affected driver, potentially causing denial of service (DoS) conditions due to kernel crashes.

Potential Impact

For European organizations, the impact of CVE-2023-52782 primarily concerns systems running Linux kernels with Mellanox network drivers (mlx5e), which are common in high-performance computing, data centers, cloud infrastructure, and enterprise networking environments. A successful exploitation leads to kernel crashes and system instability, resulting in denial of service. This can disrupt critical services, including web hosting, cloud platforms, financial transaction processing, and telecommunications infrastructure. Given the widespread use of Linux in European public and private sectors, especially in government, research institutions, and large enterprises, the vulnerability poses a risk to operational continuity. While no privilege escalation or remote code execution is indicated, the DoS impact can be severe in environments requiring high availability. Additionally, the vulnerability could be exploited by an attacker with local or network access to trigger kernel panics, potentially as part of a broader attack to degrade service or cause outages. The lack of known exploits reduces immediate risk, but the vulnerability should be addressed promptly to prevent future exploitation, especially in critical infrastructure and cloud service providers serving European customers.

Mitigation Recommendations

1. Apply the official Linux kernel patches that address this vulnerability as soon as they become available from trusted sources or Linux distributions. Monitor vendor advisories for updated kernel packages containing the fix. 2. For organizations using Mellanox hardware, ensure firmware and driver updates are current and aligned with kernel patches. 3. Implement kernel live patching solutions where possible to minimize downtime while applying fixes. 4. Restrict access to systems with affected drivers to trusted users and networks to reduce the risk of exploitation. 5. Monitor system logs for signs of kernel panics or mlx5e driver errors that could indicate attempted exploitation. 6. In virtualized or containerized environments, isolate workloads using affected drivers to limit impact scope. 7. Conduct thorough testing of kernel updates in staging environments to ensure stability before production deployment. 8. Maintain robust backup and recovery procedures to quickly restore services in case of disruption caused by this vulnerability.