csirt@kutim:~/threat-intel/cve/CVE-2021-47396

Katalog CVE

CVSS 5.5 · Medium EPSS 0,24%

Kerentanan pada linux kernel. Skor CVSS 3.1 5.5 (Medium) menurut NVD.

Deskripsi (NVD)

In the Linux kernel, the following vulnerability has been resolved: mac80211-hwsim: fix late beacon hrtimer handling Thomas explained in https://lore.kernel.org/r/87mtoeb4hb.ffs@tglx that our handling of the hrtimer here is wrong: If the timer fires late (e.g. due to vCPU scheduling, as reported by Dmitry/syzbot) then it tries to actually rearm the timer at the next deadline, which might be in the past already: 1 2 3 N N+1 | | | ... | | ^ intended to fire here (1) ^ next deadline here (2) ^ actually fired here The next time it fires, it's later, but will still try to schedule for the next deadline (now 3), etc. until it catches up with N, but that might take a long time, causing stalls etc. Now, all of this is simulation, so we just have to fix it, but note that the behaviour is wrong even per spec, since there's no value then in sending all those beacons unaligned - they should be aligned to the TBTT (1, 2, 3, ... in the picture), and if we're a bit (or a lot) late, then just resume at that point. Therefore, change the code to use hrtimer_forward_now() which will ensure that the next firing of the timer would be at N+1 (in the picture), i.e. the next interval point after the current time.

Rincian

Terbit di NVD
21 Mei 2024
Terakhir diubah
17 Juni 2026
Status NVD
Analyzed
CVSS 3.1
5.5 (Medium), sumber NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H · uraikan di kalkulator
EPSS (30 hari)
0,24% peluang dieksploitasi; lebih tinggi dari 13,8% CVE lain

Produk dan versi terdampak

VendorProdukVersi terdampak
linux linux kernel Versi 3.9 hingga sebelum 5.4.151
linux linux kernel Versi 5.5 hingga sebelum 5.10.71
linux linux kernel Versi 5.11 hingga sebelum 5.14.10
linux linux kernel Versi 5.15 rc1
linux linux kernel Versi 5.15 rc2
linux linux kernel Versi 5.15 rc3

> Data dari konfigurasi CPE di NVD.

Referensi dan perbaikan

Sumber: NVD · CVE.org · EPSS. Halaman ini disusun otomatis dari data tersebut; pembaruan terakhir 5 Okt 2026, 20:10 WITA. Kalau sistem di Perangkat Daerah memakai produk ini dan butuh bantuan, laporkan lewat kanal pelaporan.