Описание
In the Linux kernel, the following vulnerability has been resolved:
iio: buffer: Fix DMA fence leak in iio_buffer_enqueue_dmabuf()
iio_buffer_enqueue_dmabuf() allocates a struct iio_dma_fence (104 bytes,
kmalloc-128) via kmalloc_obj()+dma_fence_init(), which sets the initial
kref to 1. It then calls dma_resv_add_fence() which takes a second
reference (kref=2), and stores a raw pointer in block->fence.
On the success path the function returns without calling dma_fence_put()
to release the initial reference, so every buffer enqueue permanently
leaks one kmalloc-128 allocation.
The iio_buffer_cleanup() work item only releases the temporary reference
taken during completion signalling by iio_buffer_signal_dmabuf_done();
the initial reference from dma_fence_init() is never released.
With four iio_rwdev instances at 240kHz and 512 samples per buffer,
this produces ~1875 kmalloc-128 allocations per second matching the
observed slab growth exactly. A test with ftrace confirmed that the
dma_fence_destroy event was never triggered.
Fix by calling dma_fence_put() after dma_resv_add_fence(), transferring
ownership of the fence to the DMA reservation object. The DMA fence then
gets properly discarded after being signalled.
A flaw was found in the Linux kernel's Industrial I/O (iio) buffer component. The iio_buffer_enqueue_dmabuf() function, responsible for managing Direct Memory Access (DMA) buffers, fails to properly release a memory reference. This oversight results in a continuous memory leak, where small blocks of memory are permanently allocated but never freed. Over time, this can lead to memory exhaustion and a Denial of Service (DoS) condition, making the system unstable or unresponsive.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Fix deferred | ||
| 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 | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Not affected |
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Дополнительная информация
Статус:
EPSS
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: iio: buffer: Fix DMA fence leak in iio_buffer_enqueue_dmabuf() iio_buffer_enqueue_dmabuf() allocates a struct iio_dma_fence (104 bytes, kmalloc-128) via kmalloc_obj()+dma_fence_init(), which sets the initial kref to 1. It then calls dma_resv_add_fence() which takes a second reference (kref=2), and stores a raw pointer in block->fence. On the success path the function returns without calling dma_fence_put() to release the initial reference, so every buffer enqueue permanently leaks one kmalloc-128 allocation. The iio_buffer_cleanup() work item only releases the temporary reference taken during completion signalling by iio_buffer_signal_dmabuf_done(); the initial reference from dma_fence_init() is never released. With four iio_rwdev instances at 240kHz and 512 samples per buffer, this produces ~1875 kmalloc-128 allocations per second matching the observed slab growth exactly. A test with ftrace confirmed that the dma...
In the Linux kernel, the following vulnerability has been resolved: iio: buffer: Fix DMA fence leak in iio_buffer_enqueue_dmabuf() iio_buffer_enqueue_dmabuf() allocates a struct iio_dma_fence (104 bytes, kmalloc-128) via kmalloc_obj()+dma_fence_init(), which sets the initial kref to 1. It then calls dma_resv_add_fence() which takes a second reference (kref=2), and stores a raw pointer in block->fence. On the success path the function returns without calling dma_fence_put() to release the initial reference, so every buffer enqueue permanently leaks one kmalloc-128 allocation. The iio_buffer_cleanup() work item only releases the temporary reference taken during completion signalling by iio_buffer_signal_dmabuf_done(); the initial reference from dma_fence_init() is never released. With four iio_rwdev instances at 240kHz and 512 samples per buffer, this produces ~1875 kmalloc-128 allocations per second matching the observed slab growth exactly. A test with ftrace confirmed that the d
In the Linux kernel, the following vulnerability has been resolved: i ...
In the Linux kernel, the following vulnerability has been resolved: iio: buffer: Fix DMA fence leak in iio_buffer_enqueue_dmabuf() iio_buffer_enqueue_dmabuf() allocates a struct iio_dma_fence (104 bytes, kmalloc-128) via kmalloc_obj()+dma_fence_init(), which sets the initial kref to 1. It then calls dma_resv_add_fence() which takes a second reference (kref=2), and stores a raw pointer in block->fence. On the success path the function returns without calling dma_fence_put() to release the initial reference, so every buffer enqueue permanently leaks one kmalloc-128 allocation. The iio_buffer_cleanup() work item only releases the temporary reference taken during completion signalling by iio_buffer_signal_dmabuf_done(); the initial reference from dma_fence_init() is never released. With four iio_rwdev instances at 240kHz and 512 samples per buffer, this produces ~1875 kmalloc-128 allocations per second matching the observed slab growth exactly. A test with ftrace confirmed that th...
EPSS
5.5 Medium
CVSS3