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CVE-2021-47069

Опубликовано: 01 мар. 2024
Источник: redhat
CVSS3: 5.8
EPSS Низкий

Описание

In the Linux kernel, the following vulnerability has been resolved: ipc/mqueue, msg, sem: avoid relying on a stack reference past its expiry do_mq_timedreceive calls wq_sleep with a stack local address. The sender (do_mq_timedsend) uses this address to later call pipelined_send. This leads to a very hard to trigger race where a do_mq_timedreceive call might return and leave do_mq_timedsend to rely on an invalid address, causing the following crash: RIP: 0010:wake_q_add_safe+0x13/0x60 Call Trace: __x64_sys_mq_timedsend+0x2a9/0x490 do_syscall_64+0x80/0x680 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f5928e40343 The race occurs as:

  1. do_mq_timedreceive calls wq_sleep with the address of struct ext_wait_queue on function stack (aliased as ewq_addr here) - it holds a valid struct ext_wait_queue * as long as the stack has not been overwritten.
  2. ewq_addr gets added to info->e_wait_q[RECV].list in wq_add, and do_mq_timedsend receives it via wq_get_first_waiter(info, RECV) to call __pipelined_op.
  3. Sender calls __pipelined_op::smp_store_release(&this->state, STATE_READY). Here is where the race window begins. (this is ewq_addr.)
  4. If the receiver wakes up now in do_mq_timedreceive::wq_sleep, it will see state == STATE_READY and break.
  5. do_mq_timedreceive returns, and ewq_addr is no longer guaranteed to be a struct ext_wait_queue * since it was on do_mq_timedreceive's stack. (Although the address may not get overwritten until another function happens to touch it, which means it can persist around for an indefinite time.)
  6. do_mq_timedsend::__pipelined_op() still believes ewq_addr is a struct ext_wait_queue *, and uses it to find a task_struct to pass to the wake_q_add_safe call. In the lucky case where nothing has overwritten ewq_addr yet, ewq_addr->task is the right task_struct. In the unlucky case, __pipelined_op::wake_q_add_safe gets handed a bogus address as the receiver's task_struct causing the crash. do_mq_timedsend::__pipelined_op() should not dereference this after setting STATE_READY, as the receiver counterpart is now free to return. Change __pipelined_op to call wake_q_add_safe on the receiver's task_struct returned by get_task_struct, instead of dereferencing this which sits on the receiver's stack. As Manfred pointed out, the race potentially also exists in ipc/msg.c::expunge_all and ipc/sem.c::wake_up_sem_queue_prepare. Fix those in the same way.

    A flaw was found in the Linux kernel’s IPC system. This flaw allows an attacker to use a specially crafted program to cause a rare race condition, leading to a denial of service.

Отчет

Red Hat Enterprise Linux 9 is not affected by this vulnerability.

Меры по смягчению последствий

Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.

Затронутые пакеты

ПлатформаПакетСостояниеРекомендацияРелиз
Red Hat Enterprise Linux 6kernelOut of support scope
Red Hat Enterprise Linux 7kernelOut of support scope
Red Hat Enterprise Linux 7kernel-rtOut of support scope
Red Hat Enterprise Linux 9kernelNot affected
Red Hat Enterprise Linux 9kernel-rtNot affected
Red Hat Enterprise Linux 8kernel-rtFixedRHSA-2024:435208.07.2024
Red Hat Enterprise Linux 8kernelFixedRHSA-2024:421102.07.2024
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update SupportkernelFixedRHSA-2024:569221.08.2024
Red Hat Enterprise Linux 8.6 Telecommunications Update ServicekernelFixedRHSA-2024:569221.08.2024
Red Hat Enterprise Linux 8.6 Update Services for SAP SolutionskernelFixedRHSA-2024:569221.08.2024

Показывать по

Дополнительная информация

Статус:

Moderate
Дефект:
CWE-362
https://bugzilla.redhat.com/show_bug.cgi?id=2267513kernel: ipc/mqueue, msg, sem: avoid relying on a stack reference past its expiry

EPSS

Процентиль: 1%
0.00014
Низкий

5.8 Medium

CVSS3

Связанные уязвимости

CVSS3: 7
ubuntu
больше 1 года назад

In the Linux kernel, the following vulnerability has been resolved: ipc/mqueue, msg, sem: avoid relying on a stack reference past its expiry do_mq_timedreceive calls wq_sleep with a stack local address. The sender (do_mq_timedsend) uses this address to later call pipelined_send. This leads to a very hard to trigger race where a do_mq_timedreceive call might return and leave do_mq_timedsend to rely on an invalid address, causing the following crash: RIP: 0010:wake_q_add_safe+0x13/0x60 Call Trace: __x64_sys_mq_timedsend+0x2a9/0x490 do_syscall_64+0x80/0x680 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f5928e40343 The race occurs as: 1. do_mq_timedreceive calls wq_sleep with the address of `struct ext_wait_queue` on function stack (aliased as `ewq_addr` here) - it holds a valid `struct ext_wait_queue *` as long as the stack has not been overwritten. 2. `ewq_addr` gets added to info->e_wait_q[RECV].list in wq_add, and do_mq_timedsend receives it via wq_get_first_waiter(info, REC...

CVSS3: 7
nvd
больше 1 года назад

In the Linux kernel, the following vulnerability has been resolved: ipc/mqueue, msg, sem: avoid relying on a stack reference past its expiry do_mq_timedreceive calls wq_sleep with a stack local address. The sender (do_mq_timedsend) uses this address to later call pipelined_send. This leads to a very hard to trigger race where a do_mq_timedreceive call might return and leave do_mq_timedsend to rely on an invalid address, causing the following crash: RIP: 0010:wake_q_add_safe+0x13/0x60 Call Trace: __x64_sys_mq_timedsend+0x2a9/0x490 do_syscall_64+0x80/0x680 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f5928e40343 The race occurs as: 1. do_mq_timedreceive calls wq_sleep with the address of `struct ext_wait_queue` on function stack (aliased as `ewq_addr` here) - it holds a valid `struct ext_wait_queue *` as long as the stack has not been overwritten. 2. `ewq_addr` gets added to info->e_wait_q[RECV].list in wq_add, and do_mq_timedsend receives it v

CVSS3: 7
debian
больше 1 года назад

In the Linux kernel, the following vulnerability has been resolved: i ...

CVSS3: 7
github
больше 1 года назад

In the Linux kernel, the following vulnerability has been resolved: ipc/mqueue, msg, sem: avoid relying on a stack reference past its expiry do_mq_timedreceive calls wq_sleep with a stack local address. The sender (do_mq_timedsend) uses this address to later call pipelined_send. This leads to a very hard to trigger race where a do_mq_timedreceive call might return and leave do_mq_timedsend to rely on an invalid address, causing the following crash: RIP: 0010:wake_q_add_safe+0x13/0x60 Call Trace: __x64_sys_mq_timedsend+0x2a9/0x490 do_syscall_64+0x80/0x680 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f5928e40343 The race occurs as: 1. do_mq_timedreceive calls wq_sleep with the address of `struct ext_wait_queue` on function stack (aliased as `ewq_addr` here) - it holds a valid `struct ext_wait_queue *` as long as the stack has not been overwritten. 2. `ewq_addr` gets added to info->e_wait_q[RECV].list in wq_add, and do_mq_timedsend receives i...

CVSS3: 7
fstec
около 4 лет назад

Уязвимость функции __pipelined_op() модуля ipc/mqueue.c подсистемы межпроцессного взаимодействия IPC ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании

EPSS

Процентиль: 1%
0.00014
Низкий

5.8 Medium

CVSS3