Описание
In the Linux kernel, the following vulnerability has been resolved: RDMA/mlx5: Fix unsafe xarray access in implicit ODP handling __xa_store() and __xa_erase() were used without holding the proper lock, which led to a lockdep warning due to unsafe RCU usage. This patch replaces them with xa_store() and xa_erase(), which perform the necessary locking internally.
WARNING: suspicious RCPU usage 6.14.0-rc7_for_upstream_debug_2025_03_18_15_01 #1 Not tainted
./include/linux/xarray.h:1211 suspicious rcu_dereference_protected() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
3 locks held by kworker/u136:0/219:
at: process_one_work+0xbe4/0x15f0
process_one_work+0x75c/0x15f0
pagefault_mr+0x9a5/0x1390 [mlx5_ib]
stack backtrace:
CPU: 14 UID: 0 PID: 219 Comm: kworker/u136:0 Not tainted
6.14.0-rc7_for_upstream_debug_2025_03_18_15_01 #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
Workqueue: mlx5_ib_page_fault mlx5_ib_eqe_pf_action [mlx5_ib]
Call Trace:
dump_stack_lvl+0xa8/0xc0
lockdep_rcu_suspicious+0x1e6/0x260
xas_create+0xb8a/0xee0
xas_store+0x73/0x14c0
__xa_store+0x13c/0x220
? xa_store_range+0x390/0x390
? spin_bug+0x1d0/0x1d0
pagefault_mr+0xcb5/0x1390 [mlx5_ib]
? _raw_spin_unlock+0x1f/0x30
mlx5_ib_eqe_pf_action+0x3be/0x2620 [mlx5_ib]
? lockdep_hardirqs_on_prepare+0x400/0x400
? mlx5_ib_invalidate_range+0xcb0/0xcb0 [mlx5_ib]
process_one_work+0x7db/0x15f0
? pwq_dec_nr_in_flight+0xda0/0xda0
? assign_work+0x168/0x240
worker_thread+0x57d/0xcd0
? rescuer_thread+0xc40/0xc40
kthread+0x3b3/0x800
? kthread_is_per_cpu+0xb0/0xb0
? lock_downgrade+0x680/0x680
? do_raw_spin_lock+0x12d/0x270
? spin_bug+0x1d0/0x1d0
? finish_task_switch.isra.0+0x284/0x9e0
? lockdep_hardirqs_on_prepare+0x284/0x400
? kthread_is_per_cpu+0xb0/0xb0
ret_from_fork+0x2d/0x70
? kthread_is_per_cpu+0xb0/0xb0
ret_from_fork_asm+0x11/0x20
A flaw was found in the Linux kernel's Remote Direct Memory Access (RDMA) subsystem, specifically within the mlx5 driver's implicit On-Demand Paging (ODP) handling. A local user could exploit this vulnerability due to unsafe access to xarray data structures, where __xa_store() and __xa_erase() functions were used without proper locking. This improper handling can lead to a lockdep warning and unsafe Read-Copy Update (RCU) usage, potentially resulting in a denial of service (DoS) for the system.
Отчет
A moderate-severity flaw was found in the Linux kernel's mlx5 RDMA driver within its implicit On-Demand Paging (ODP) handling. The affected code used the __xa_store() and __xa_erase() xarray operations without holding the proper lock, which constitutes unsafe RCU usage and triggers a lockdep warning. A local user with the ability to trigger mlx5 ODP page-fault handling could potentially exploit this flaw to cause a denial of service. Red Hat rated this flaw Moderate (CVSS 3.1 score 5.5, AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H) because only availability is affected; the higher upstream CVE.org score of 7.8 additionally assumes confidentiality and integrity impact, which the available evidence does not support. Red Hat Enterprise Linux 9 kernel and kernel-rt are affected; the vulnerable code is not present in Red Hat Enterprise Linux 6, 7, 8, and 10 or in Red Hat In-Vehicle OS, so those products are not affected. For the affected RHEL 9 streams the fix has been deferred given the limited practical impact, which is a lockdep warning and potential local denial of service restricted to a specific RDMA/ODP use case; the residual risk is that a local user on a system using mlx5 RDMA with implicit ODP could trigger a kernel-level availability impact.
Меры по смягчению последствий
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Not affected | ||
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Fix deferred |
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Дополнительная информация
Статус:
EPSS
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: RDMA/mlx5: Fix unsafe xarray access in implicit ODP handling __xa_store() and __xa_erase() were used without holding the proper lock, which led to a lockdep warning due to unsafe RCU usage. This patch replaces them with xa_store() and xa_erase(), which perform the necessary locking internally. ============================= WARNING: suspicious RCPU usage 6.14.0-rc7_for_upstream_debug_2025_03_18_15_01 #1 Not tainted ----------------------------- ./include/linux/xarray.h:1211 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 3 locks held by kworker/u136:0/219: at: process_one_work+0xbe4/0x15f0 process_one_work+0x75c/0x15f0 pagefault_mr+0x9a5/0x1390 [mlx5_ib] stack backtrace: CPU: 14 UID: 0 PID: 219 Comm: kworker/u136:0 Not tainted 6.14.0-rc7_for_upstream_debug_2025_03_18_15_01 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel...
In the Linux kernel, the following vulnerability has been resolved: RDMA/mlx5: Fix unsafe xarray access in implicit ODP handling __xa_store() and __xa_erase() were used without holding the proper lock, which led to a lockdep warning due to unsafe RCU usage. This patch replaces them with xa_store() and xa_erase(), which perform the necessary locking internally. ============================= WARNING: suspicious RCPU usage 6.14.0-rc7_for_upstream_debug_2025_03_18_15_01 #1 Not tainted ----------------------------- ./include/linux/xarray.h:1211 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 3 locks held by kworker/u136:0/219: at: process_one_work+0xbe4/0x15f0 process_one_work+0x75c/0x15f0 pagefault_mr+0x9a5/0x1390 [mlx5_ib] stack backtrace: CPU: 14 UID: 0 PID: 219 Comm: kworker/u136:0 Not tainted 6.14.0-rc7_for_upstream_debug_2025_03_18_15_01 #1 Hardware name:
In the Linux kernel, the following vulnerability has been resolved: R ...
In the Linux kernel, the following vulnerability has been resolved: RDMA/mlx5: Fix unsafe xarray access in implicit ODP handling __xa_store() and __xa_erase() were used without holding the proper lock, which led to a lockdep warning due to unsafe RCU usage. This patch replaces them with xa_store() and xa_erase(), which perform the necessary locking internally. ============================= WARNING: suspicious RCPU usage 6.14.0-rc7_for_upstream_debug_2025_03_18_15_01 #1 Not tainted ----------------------------- ./include/linux/xarray.h:1211 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 3 locks held by kworker/u136:0/219: at: process_one_work+0xbe4/0x15f0 process_one_work+0x75c/0x15f0 pagefault_mr+0x9a5/0x1390 [mlx5_ib] stack backtrace: CPU: 14 UID: 0 PID: 219 Comm: kworker/u136:0 Not tainted 6.14.0-rc7_for_upstream_debug_2025_03_18_15_01 #1 Hardware nam...
Уязвимость функции __xa_store() и __xa_erase() модуля drivers/infiniband/hw/mlx5/odp.c ядра операционных систем Linux, позволяющая нарушителю вызвать отказ в обслуживании
EPSS
5.5 Medium
CVSS3