CVE-2023-54291
Description
In the Linux kernel, the following vulnerability has been resolved:
vduse: fix NULL pointer dereference
vduse_vdpa_set_vq_affinity callback can be called with NULL value as cpu_mask when deleting the vduse device.
This patch resets virtqueue's IRQ affinity mask value to set all CPUs instead of dereferencing NULL cpu_mask.
[ 4760.952149] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 4760.959110] #PF: supervisor read access in kernel mode [ 4760.964247] #PF: error_code(0x0000) - not-present page [ 4760.969385] PGD 0 P4D 0 [ 4760.971927] Oops: 0000 [#1] PREEMPT SMP PTI [ 4760.976112] CPU: 13 PID: 2346 Comm: vdpa Not tainted 6.4.0-rc6+ #4 [ 4760.982291] Hardware name: Dell Inc. PowerEdge R640/0W23H8, BIOS 2.8.1 06/26/2020 [ 4760.989769] RIP: 0010:memcpy_orig+0xc5/0x130 [ 4760.994049] Code: 16 f8 4c 89 07 4c 89 4f 08 4c 89 54 17 f0 4c 89 5c 17 f8 c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 83 fa 08 72 1b <4c> 8b 06 4c 8b 4c 16 f8 4c 89 07 4c 89 4c 17 f8 c3 cc cc cc cc 66 [ 4761.012793] RSP: 0018:ffffb1d565abb830 EFLAGS: 00010246 [ 4761.018020] RAX: ffff9f4bf6b27898 RBX: ffff9f4be23969c0 RCX: ffff9f4bcadf6400 [ 4761.025152] RDX: 0000000000000008 RSI: 0000000000000000 RDI: ffff9f4bf6b27898 [ 4761.032286] RBP: 0000000000000000 R08: 0000000000000008 R09: 0000000000000000 [ 4761.039416] R10: 0000000000000000 R11: 0000000000000600 R12: 0000000000000000 [ 4761.046549] R13: 0000000000000000 R14: 0000000000000080 R15: ffffb1d565abbb10 [ 4761.053680] FS: 00007f64c2ec2740(0000) GS:ffff9f635f980000(0000) knlGS:0000000000000000 [ 4761.061765] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 4761.067513] CR2: 0000000000000000 CR3: 0000001875270006 CR4: 00000000007706e0 [ 4761.074645] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 4761.081775] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 4761.088909] PKRU: 55555554 [ 4761.091620] Call Trace: [ 4761.094074] [ 4761.096180] ? __die+0x1f/0x70 [ 4761.099238] ? page_fault_oops+0x171/0x4f0 [ 4761.103340] ? exc_page_fault+0x7b/0x180 [ 4761.107265] ? asm_exc_page_fault+0x22/0x30 [ 4761.111460] ? memcpy_orig+0xc5/0x130 [ 4761.115126] vduse_vdpa_set_vq_affinity+0x3e/0x50 [vduse] [ 4761.120533] virtnet_clean_affinity.part.0+0x3d/0x90 [virtio_net] [ 4761.126635] remove_vq_common+0x1a4/0x250 [virtio_net] [ 4761.131781] virtnet_remove+0x5d/0x70 [virtio_net] [ 4761.136580] virtio_dev_remove+0x3a/0x90 [ 4761.140509] device_release_driver_internal+0x19b/0x200 [ 4761.145742] bus_remove_device+0xc2/0x130 [ 4761.149755] device_del+0x158/0x3e0 [ 4761.153245] ? kernfs_find_ns+0x35/0xc0 [ 4761.157086] device_unregister+0x13/0x60 [ 4761.161010] unregister_virtio_device+0x11/0x20 [ 4761.165543] device_release_driver_internal+0x19b/0x200 [ 4761.170770] bus_remove_device+0xc2/0x130 [ 4761.174782] device_del+0x158/0x3e0 [ 4761.178276] ? __pfx_vdpa_name_match+0x10/0x10 [vdpa] [ 4761.183336] device_unregister+0x13/0x60 [ 4761.187260] vdpa_nl_cmd_dev_del_set_doit+0x63/0xe0 [vdpa]
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
A NULL pointer dereference in the Linux kernel's vduse driver occurs when deleting a vduse device, due to a lack of NULL check for cpu_mask in vduse_vdpa_set_vq_affinity.
Vulnerability
Description
The vulnerability is a NULL pointer dereference in the Linux kernel's vduse driver, within the vduse_vdpa_set_vq_affinity callback. When a vduse device is being deleted, the cpu_mask parameter can be passed as NULL. The code attempts to dereference this NULL pointer, leading to a kernel crash (oops) as shown by the kernel BUG report [1]. The root cause is the absence of a NULL check before using cpu_mask.
Exploitation
The flaw is triggered by a local user performing device deletion operations (e.g., running vdpa tool commands). No special privileges beyond those required to manage vduse devices are necessary, but the attacker must have access to the host system and the ability to create and delete vduse devices. The attack surface is limited to local exploitation, requiring the attacker to already have a degree of system access.
Impact
An attacker who can trigger the deletion of a vduse device can cause a kernel NULL pointer dereference, resulting in a system crash (denial of service). This can disrupt services or cause a system reboot, potentially leading to availability impacts. There is no evidence of code execution or privilege escalation from this bug.
Mitigation
The fix has been applied in the Linux kernel by ensuring that when cpu_mask is NULL, the virtqueue's affinity mask is reset to allow all CPUs instead of dereferencing the NULL pointer [1]. Users should apply the stable kernel update containing this commit to remediate the vulnerability.
AI Insight generated on May 19, 2026. Synthesized from this CVE's description and the cited reference URLs; citations are validated against the source bundle.
Patches
2f9d46429de2af06cf1e1a503Vulnerability mechanics
Generated on May 9, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.
References
2News mentions
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