CVE-2026-98302
net: fddi: skfp: fix NULL deref when setting the MAC address while down
Что произошло
In the Linux kernel, the following vulnerability has been resolved: net: fddi: skfp: fix NULL deref when setting the MAC address while down skfp_ctl_set_mac_address() calls ResetAdapter() unconditionally, without checking netif_running(). ResetAdapter() first calls card_stop(), which sets smc->hw.hw_state to STOPPED, and then mac_drv_clear_tx_queue(), which walks the two transmit queues: for (i = QUEUE_S; i hw.fp.tx[i] ; ... t = queue->tx_curr_get ; smc->hw.fp.tx[] is only populated by init_tx(), which is reached from skfp_open() through init_smt() -> init_fddi_driver() -> init_fplus() -> init_mac() -> init_tx(). The private area is allocated and zeroed by alloc_fddidev(), so on an interface that has never been brought up both queue pointers are still NULL. The hw_state test at the top of mac_drv_clear_tx_queue() does not catch this, because card_stop() has just set STOPPED; the function proceeds into the loop and dereferences NULL. ResetAdapter() does call init_smt() itself, but only after the queues have been cleared. Setting the MAC address on a down interface therefore oopses: ip link set dev fddi0 address 02:00:00:00:00:01 BUG: KASAN: null-ptr-deref in mac_drv_clear_tx_queue+0x68/0x2c0 [skfp] Read of size 8 at addr 0000000000000010 by task ip/302 Call Trace: mac_drv_clear_tx_queue+0x68/0x2c0 [skfp 6c01d4bab63c36978bd0a7d7e90837adb44cc37b] ResetAdapter+0x29/0x100 [skfp 6c01d4bab63c36978bd0a7d7e90837adb44cc37b] skfp_ctl_set_mac_address+0x57/0x80 [skfp 6c01d4bab63c36978bd0a7d7e90837adb44cc37b] netif_set_mac_address+0x1e4/0x2c0 do_setlink+0x684/0x2680 Address 0x10 is the offset of tx_curr_get, the third pointer in struct s_smt_tx_queue, on 64-bit. mac_drv_clear_rx_queue(), which ResetAdapter() calls immediately afterwards, dereferences smc->hw.fp.rx[QUEUE_R1] in the same way behind the same ineffective hw_state test; the transmit queue merely crashes first. Both are covered by the guard below. Skip the adapter reset when the interface is down. dev_addr_set() is left unconditional, so the new address is still recorded in dev->dev_addr. Nothing is lost by not resetting the adapter here: skfp_open() deliberately re-reads the factory address on every open, read_address(smc, NULL); eth_hw_addr_set(dev, smc->hw.fddi_canon_addr.a); and the comment above it states this is done to discard exactly such an address override across a close/open cycle. An address set while the interface is down could not have survived the following open even before this change, so the guard removes no working behaviour. Guarding the hardware side of ndo_set_mac_address() with netif_running() is established practice; skge_set_mac_address() has done so since commit 2eb3e621c4e0 ("skge: set mac address bonding fix"). Guarding the reset as a whole, rather than NULL-checking the queues, is also what the rest of the driver expects. After a previous open/close the queue pointers are stale but non-NULL, so there is no crash, yet ResetAdapter() goes on to call smt_online() and STI_FBI() ("Enable Board Interrupts") while skfp_close() has already called free_irq() - the adapter would be brought back online with no handler installed. The only other ResetAdapter() caller is skfp_interrupt(), which by construction runs only while the device is open. Found by automated driver testing against an emulated SysKonnect FDDI adapter under a KASAN-enabled 7.0.0 kernel. Triggering it requires CAP_NET_ADMIN.
Что это значит
В источнике описана ошибка безопасности в перечисленных продуктах. Фактический риск зависит от установленной версии, конфигурации и доступности компонента; проверьте условия в первичном бюллетене.
Что делать
1. Проверьте, затронуты ли вы
Соберите инвентаризацию и сравните с таблицей затронутых версий. Эти команды только показывают установленные компоненты и сами по себе не доказывают наличие CVE.
dpkg-query -W -f='${Package} ${Version}\n'rpm -qa --qf '%{NAME}\t%{VERSION}-%{RELEASE}\n'Get-HotFix | Select-Object HotFixID, InstalledOn
2. Установите исправление
Сверьте точный продукт и версию с бюллетенем вендора. Установите указанное в нём исправление после резервного копирования и проверки совместимости. Подтверждённая целевая версия в источниках отсутствует.
3. Временные меры
До проверки бюллетеня ограничьте доступ к затронутому компоненту доверенными узлами. Оцените сегментацию и отключение ненужных интерфейсов с владельцем сервиса; универсального правила WAF для этой CVE не подтверждено.
4. Проверьте следы эксплуатации
Проверьте аномальные входы, новые учётные записи, ошибки и необычные дочерние процессы в затронутом сервисе. Публичные проверенные правила обнаружения не включены в запись; отсутствие сигналов не доказывает отсутствие компрометации.
5. После исправления
- Проверьте фактическую версию и результат установки по бюллетеню.
- При необходимости перезапустите сервисы в согласованное окно.
- Повторите проверку сканером и функциональные проверки.
- Зафиксируйте результат, дату, владельца и оставшийся риск.
Продукты и затронутые версии
Linux / Linux
{
"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "835903bea770ad96ab4322e18d98e00f8e0b39c3",
"versionType": "git"
}{
"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "5fd0f401b3eee95c93daa35ef99cb03d676031f0",
"versionType": "git"
}{
"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "731db6110b3148331ed8d5d11a564bfd520721d9",
"versionType": "git"
}{
"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "822903ed991971780db1db1be31a4f00e2b13e30",
"versionType": "git"
}{
"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "616ba18b2cfb72b7bea214bdd72df2485b2e37dc",
"versionType": "git"
}{
"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "d6f63fdb298d546a47790cb373db65462c264d04",
"versionType": "git"
}{
"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "438131e7ae847e907d345bf504d7e25585561b5c",
"versionType": "git"
}{
"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "7c8810c2e69c3d9ca6df870b40ae9218e50b4fb1",
"versionType": "git"
}Linux / Linux
{
"status": "affected",
"version": "2.6.12"
}{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.12",
"versionType": "semver"
}{
"status": "unaffected",
"version": "5.10.271",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
}{
"status": "unaffected",
"version": "5.15.222",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
}{
"status": "unaffected",
"version": "6.1.189",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
}{
"status": "unaffected",
"version": "6.6.158",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
}{
"status": "unaffected",
"version": "6.12.112",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
}{
"status": "unaffected",
"version": "6.18.54",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
}{
"status": "unaffected",
"version": "7.2.8",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
}{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}CVSS: оценки и векторы
Оценка CVSS отсутствует.
Источники и ссылки
Происхождение полей
{
"cwes": [],
"epss": {
"source": "epss",
"received_at": "2026-11-02T21:15:46.197953+00:00"
},
"title": {
"source": "cve",
"received_at": "2026-10-28T20:13:06.385508+00:00"
},
"scores": [],
"status": {
"source": "cve",
"received_at": "2026-10-28T20:13:06.385508+00:00"
},
"affected": [
"cve"
],
"published": {
"source": "cve",
"received_at": "2026-10-28T20:13:06.385508+00:00"
},
"solutions": [],
"percentile": {
"source": "epss",
"received_at": "2026-11-02T21:15:46.197953+00:00"
},
"references": [
"cve"
],
"description": {
"source": "cve",
"received_at": "2026-10-28T20:13:06.385508+00:00"
},
"workarounds": [],
"configurations": []
}Хронология записи
- Данные обновлены03.11.2026, 00:15
- Данные обновлены02.11.2026, 00:13
- Данные обновлены31.10.2026, 12:00
- Данные обновлены29.10.2026, 12:47
- Опубликована28.10.2026, 23:13
Личная заметка и статус
Другие CVE того же продукта
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|---|---|---|---|---|---|---|
| CVE-2026-99270 tcp: Fix potential UAF in reqsk_timer_handler(). Linux / Linux | Высокий | 8.1 | — | 03.11.2026 | ||
| CVE-2026-99269 sched_ext: Wait for SCX_OPSS_DISPATCHING before moving tasks off DSQs Linux / Linux | Высокий | 7.8 | — | 03.11.2026 | ||
| CVE-2026-99268 io_uring: wake ring pollers for local task_work Linux / Linux | Информационный | — | — | 03.11.2026 | ||
| CVE-2026-99267 io_uring/napi: make stale entries time out after 60s Linux / Linux | Информационный | — | — | 03.11.2026 | ||
| CVE-2026-99266 io_uring/zcrx: fix buffer offsets in areas above 4GB Linux / Linux | Информационный | — | — | 03.11.2026 |