CVE-2024-26698
Vulnerability Summary
Timeline
Description
In the Linux kernel, the following vulnerability has been resolved: hv_netvsc: Fix race condition between netvsc_probe and netvsc_remove In commit ac5047671758 ("hv_netvsc: Disable NAPI before closing the VMBus channel"), napi_disable was getting called for all channels, including all subchannels without confirming if they are enabled or not. This caused hv_netvsc getting hung at napi_disable, when netvsc_probe() has finished running but nvdev->subchan_work has not started yet. netvsc_subchan_work() -> rndis_set_subchannel() has not created the sub-channels and because of that netvsc_sc_open() is not running. netvsc_remove() calls cancel_work_sync(&nvdev->subchan_work), for which netvsc_subchan_work did not run. netif_napi_add() sets the bit NAPI_STATE_SCHED because it ensures NAPI cannot be scheduled. Then netvsc_sc_open() -> napi_enable will clear the NAPIF_STATE_SCHED bit, so it can be scheduled. napi_disable() does the opposite. Now during netvsc_device_remove(), when napi_disable is called for those subchannels, napi_disable gets stuck on infinite msleep. This fix addresses this problem by ensuring that napi_disable() is not getting called for non-enabled NAPI struct. But netif_napi_del() is still necessary for these non-enabled NAPI struct for cleanup purpose. Call trace: [ 654.559417] task:modprobe state:D stack: 0 pid: 2321 ppid: 1091 flags:0x00004002 [ 654.568030] Call Trace: [ 654.571221] <TASK> [ 654.573790] __schedule+0x2d6/0x960 [ 654.577733] schedule+0x69/0xf0 [ 654.581214] schedule_timeout+0x87/0x140 [ 654.585463] ? __bpf_trace_tick_stop+0x20/0x20 [ 654.590291] msleep+0x2d/0x40 [ 654.593625] napi_disable+0x2b/0x80 [ 654.597437] netvsc_device_remove+0x8a/0x1f0 [hv_netvsc] [ 654.603935] rndis_filter_device_remove+0x194/0x1c0 [hv_netvsc] [ 654.611101] ? do_wait_intr+0xb0/0xb0 [ 654.615753] netvsc_remove+0x7c/0x120 [hv_netvsc] [ 654.621675] vmbus_remove+0x27/0x40 [hv_vmbus]
CVSS Metrics
- v3.1•MEDIUM•Score: 4.7CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Trends
Current EPSS score: 0.01%• Percentile: 1%
Techniques & Countermeasures
- CWE-362•Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
Affected Systems
- debian•debian_linux
10.0
- linux•linux
≥ ac5047671758ad4be9f93898247b3a8b6dfde4c7, < 9ec807e7b6f5fcf9499f3baa69f254bb239a847f | ≥ ac5047671758ad4be9f93898247b3a8b6dfde4c7, < 7656372ae190e54e8c8cf1039725a5ea59fdf84a | ≥ ac5047671758ad4be9f93898247b3a8b6dfde4c7, < 48a8ccccffbae10c91d31fc872db5c31aba07518 | ≥ ac5047671758ad4be9f93898247b3a8b6dfde4c7, < 22a77c0f5b8233237731df3288d067af51a2fd7b | ≥ ac5047671758ad4be9f93898247b3a8b6dfde4c7, < 0e8875de9dad12805ff66e92cd5edea6a421f1cd | ≥ ac5047671758ad4be9f93898247b3a8b6dfde4c7, < e0526ec5360a48ad3ab2e26e802b0532302a7e11 | 5.8
- linux•linux_kernel
≥ 5.8, < 5.10.210 | ≥ 5.11, < 5.15.149 | ≥ 5.16, < 6.1.79 | ≥ 6.2, < 6.6.18 | ≥ 6.7, < 6.7.6 | 6.8:rc1 | 6.8:rc2
References (7)
- https://git.kernel.org/stable/c/9ec807e7b6f5fcf9499f3baa69f254bb239a847f
- https://git.kernel.org/stable/c/7656372ae190e54e8c8cf1039725a5ea59fdf84a
- https://git.kernel.org/stable/c/48a8ccccffbae10c91d31fc872db5c31aba07518
- https://git.kernel.org/stable/c/22a77c0f5b8233237731df3288d067af51a2fd7b
- https://git.kernel.org/stable/c/0e8875de9dad12805ff66e92cd5edea6a421f1cd
- https://git.kernel.org/stable/c/e0526ec5360a48ad3ab2e26e802b0532302a7e11
- https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html