CVE-2022-49443
In the Linux kernel, the following vulnerability has been resolved:
list: fix a data-race around ep->rdllist
ep_poll() first calls ep_events_available() with no lock held and checks if ep->rdllist is empty by list_empty_careful(), which reads rdllist->prev. Thus all accesses to it need some protection to avoid store/load-tearing.
Note INIT_LIST_HEAD_RCU() already has the annotation for both prev and next.
Commit bf3b9f6372c4 ("epoll: Add busy poll support to epoll with socket fds.") added the first lockless ep_events_available(), and commit c5a282e9635e ("fs/epoll: reduce the scope of wq lock in epoll_wait()") made some ep_events_available() calls lockless and added single call under a lock, finally commit e59d3c64cba6 ("epoll: eliminate unnecessary lock for zero timeout") made the last ep_events_available() lockless.
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write to 0xffff88810480c7d8 of 8 bytes by task 1802 on cpu 0: INIT_LIST_HEAD include/linux/list.h:38 [inline] list_splice_init include/linux/list.h:492 [inline] ep_start_scan fs/eventpoll.c:622 [inline] ep_send_events fs/eventpoll.c:1656 [inline] ep_poll fs/eventpoll.c:1806 [inline] do_epoll_wait+0x4eb/0xf40 fs/eventpoll.c:2234 do_epoll_pwait fs/eventpoll.c:2268 [inline] __do_sys_epoll_pwait fs/eventpoll.c:2281 [inline] __se_sys_epoll_pwait+0x12b/0x240 fs/eventpoll.c:2275 __x64_sys_epoll_pwait+0x74/0x80 fs/eventpoll.c:2275 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae
read to 0xffff88810480c7d8 of 8 bytes by task 1799 on cpu 1: list_empty_careful include/linux/list.h:329 [inline] ep_events_available fs/eventpoll.c:381 [inline] ep_poll fs/eventpoll.c:1797 [inline] do_epoll_wait+0x279/0xf40 fs/eventpoll.c:2234 do_epoll_pwait fs/eventpoll.c:2268 [inline] __do_sys_epoll_pwait fs/eventpoll.c:2281 [inline] __se_sys_epoll_pwait+0x12b/0x240 fs/eventpoll.c:2275 __x64_sys_epoll_pwait+0x74/0x80 fs/eventpoll.c:2275 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae
value changed: 0xffff88810480c7d0 -> 0xffff888103c15098
Detalles técnicos trazas, registros y código del informe original
BUG: KCSAN: data-race in do_epoll_wait / do_epoll_wait Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 1799 Comm: syz-fuzzer Tainted: G W 5.17.0-rc7-syzkaller-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
- Puntuación base: 4.7
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.18%
- Percentil entre todas las CVEs puntuadas: 7
- Fecha de la puntuación: 5/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
CWE
- CWE-362
- CWE-362
Referencias
JSON original (NVD)
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nlist: fix a data-race around ep->rdllist\n\nep_poll() first calls ep_events_available() with no lock held and checks\nif ep->rdllist is empty by list_empty_careful(), which reads\nrdllist->prev. Thus all accesses to it need some protection to avoid\nstore/load-tearing.\n\nNote INIT_LIST_HEAD_RCU() already has the annotation for both prev\nand next.\n\nCommit bf3b9f6372c4 (\"epoll: Add busy poll support to epoll with socket\nfds.\") added the first lockless ep_events_available(), and commit\nc5a282e9635e (\"fs/epoll: reduce the scope of wq lock in epoll_wait()\")\nmade some ep_events_available() calls lockless and added single call under\na lock, finally commit e59d3c64cba6 (\"epoll: eliminate unnecessary lock\nfor zero timeout\") made the last ep_events_available() lockless.\n\nBUG: KCSAN: data-race in do_epoll_wait / do_epoll_wait\n\nwrite to 0xffff88810480c7d8 of 8 bytes by task 1802 on cpu 0:\n INIT_LIST_HEAD include/linux/list.h:38 [inline]\n list_splice_init include/linux/list.h:492 [inline]\n ep_start_scan fs/eventpoll.c:622 [inline]\n ep_send_events fs/eventpoll.c:1656 [inline]\n ep_poll fs/eventpoll.c:1806 [inline]\n do_epoll_wait+0x4eb/0xf40 fs/eventpoll.c:2234\n do_epoll_pwait fs/eventpoll.c:2268 [inline]\n __do_sys_epoll_pwait fs/eventpoll.c:2281 [inline]\n __se_sys_epoll_pwait+0x12b/0x240 fs/eventpoll.c:2275\n __x64_sys_epoll_pwait+0x74/0x80 fs/eventpoll.c:2275\n do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80\n entry_SYSCALL_64_after_hwframe+0x44/0xae\n\nread to 0xffff88810480c7d8 of 8 bytes by task 1799 on cpu 1:\n list_empty_careful include/linux/list.h:329 [inline]\n ep_events_available fs/eventpoll.c:381 [inline]\n ep_poll fs/eventpoll.c:1797 [inline]\n do_epoll_wait+0x279/0xf40 fs/eventpoll.c:2234\n do_epoll_pwait fs/eventpoll.c:2268 [inline]\n __do_sys_epoll_pwait fs/eventpoll.c:2281 [inline]\n __se_sys_epoll_pwait+0x12b/0x240 fs/eventpoll.c:2275\n __x64_sys_epoll_pwait+0x74/0x80 fs/eventpoll.c:2275\n do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80\n entry_SYSCALL_64_after_hwframe+0x44/0xae\n\nvalue changed: 0xffff88810480c7d0 -> 0xffff888103c15098\n\nReported by Kernel Concurrency Sanitizer on:\nCPU: 1 PID: 1799 Comm: syz-fuzzer Tainted: G W 5.17.0-rc7-syzkaller-dirty #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011"
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: list: se corrige una ejecución de datos alrededor de ep->rdllist ep_poll() primero llama a ep_events_available() sin bloqueo mantenido y verifica si ep->rdllist está vacío mediante list_empty_careful(), que lee rdllist->prev. Por lo tanto, todos los accesos a él necesitan alguna protección para evitar el desgarro de almacenamiento/carga. Tenga en cuenta que INIT_LIST_HEAD_RCU() ya tiene la anotación tanto para prev como para next. El commit bf3b9f6372c4 (\"epoll: Agregar soporte de sondeo ocupado a epoll con fds de socket\") agregó el primer ep_events_available() sin bloqueo, y el commit c5a282e9635e (\"fs/epoll: reducir el alcance del bloqueo wq en epoll_wait()\") hizo que algunas llamadas ep_events_available() no tuvieran bloqueo y agregó una sola llamada bajo un bloqueo, finalmente el commit e59d3c64cba6 (\"epoll: eliminar el bloqueo innecesario para tiempo de espera cero\") hizo que el último ep_events_available() no tuviera bloqueo. ERROR: KCSAN: data-race in do_epoll_wait / do_epoll_wait write to 0xffff88810480c7d8 of 8 bytes by task 1802 on cpu 0: INIT_LIST_HEAD include/linux/list.h:38 [inline] list_splice_init include/linux/list.h:492 [inline] ep_start_scan fs/eventpoll.c:622 [inline] ep_send_events fs/eventpoll.c:1656 [inline] ep_poll fs/eventpoll.c:1806 [inline] do_epoll_wait+0x4eb/0xf40 fs/eventpoll.c:2234 do_epoll_pwait fs/eventpoll.c:2268 [inline] __do_sys_epoll_pwait fs/eventpoll.c:2281 [inline] __se_sys_epoll_pwait+0x12b/0x240 fs/eventpoll.c:2275 __x64_sys_epoll_pwait+0x74/0x80 fs/eventpoll.c:2275 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff88810480c7d8 of 8 bytes by task 1799 on cpu 1: list_empty_careful include/linux/list.h:329 [inline] ep_events_available fs/eventpoll.c:381 [inline] ep_poll fs/eventpoll.c:1797 [inline] do_epoll_wait+0x279/0xf40 fs/eventpoll.c:2234 do_epoll_pwait fs/eventpoll.c:2268 [inline] __do_sys_epoll_pwait fs/eventpoll.c:2281 [inline] __se_sys_epoll_pwait+0x12b/0x240 fs/eventpoll.c:2275 __x64_sys_epoll_pwait+0x74/0x80 fs/eventpoll.c:2275 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0xffff88810480c7d0 -> 0xffff888103c15098 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 1799 Comm: syz-fuzzer Tainted: G W 5.17.0-rc7-syzkaller-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 "
}
],
"lastModified": "2026-06-17T05:18:03.853",
"configurations": [
{
"nodes": [
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