Описание
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_fs: Fix DMA fence leak
In ffs_dmabuf_transfer(), a ffs_dma_fence object is kmalloc'd, with the underlying dma_fence later initialized by dma_fence_init(), which sets its kref counter to 1. Then, dma_resv_add_fence() gets a second reference, and a pointer to the ffs_dma_fence is passed as the usb_request's "context" field.
The dma-resv mechanism will manage the second reference, but the first reference is never properly released; the ffs_dmabuf_cleanup() function decreases the reference count, but only to balance with the reference grab in ffs_dmabuf_signal_done().
The code will then slowly leak memory as more ffs_dma_fence objects are created without being ever freed.
Address this issue by transferring ownership of the fence to the DMA reservation object, by calling dma_fence_put() right after dma_resv_add_fence(). The ffs_dma_fence then gets properly discarded after being signalled.
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_fs: Fix DMA fence leak
In ffs_dmabuf_transfer(), a ffs_dma_fence object is kmalloc'd, with the underlying dma_fence later initialized by dma_fence_init(), which sets its kref counter to 1. Then, dma_resv_add_fence() gets a second reference, and a pointer to the ffs_dma_fence is passed as the usb_request's "context" field.
The dma-resv mechanism will manage the second reference, but the first reference is never properly released; the ffs_dmabuf_cleanup() function decreases the reference count, but only to balance with the reference grab in ffs_dmabuf_signal_done().
The code will then slowly leak memory as more ffs_dma_fence objects are created without being ever freed.
Address this issue by transferring ownership of the fence to the DMA reservation object, by calling dma_fence_put() right after dma_resv_add_fence(). The ffs_dma_fence then gets properly discarded after being signalled.
Ссылки
- https://nvd.nist.gov/vuln/detail/CVE-2026-64328
- https://git.kernel.org/stable/c/0cae3d6109427c455bad0a18dfb3e2a91657e38a
- https://git.kernel.org/stable/c/b7475b2dce5e121e687280ba5732ccefe77ffd2f
- https://git.kernel.org/stable/c/baa6b6068a3f2bf2ed525a1cb37975905dadc658
- https://git.kernel.org/stable/c/e086c16962a1b0142e2675610e9c06fcfcd4c3a8
EPSS
CVE ID
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_fs: Fix DMA fence leak In ffs_dmabuf_transfer(), a ffs_dma_fence object is kmalloc'd, with the underlying dma_fence later initialized by dma_fence_init(), which sets its kref counter to 1. Then, dma_resv_add_fence() gets a second reference, and a pointer to the ffs_dma_fence is passed as the usb_request's "context" field. The dma-resv mechanism will manage the second reference, but the first reference is never properly released; the ffs_dmabuf_cleanup() function decreases the reference count, but only to balance with the reference grab in ffs_dmabuf_signal_done(). The code will then slowly leak memory as more ffs_dma_fence objects are created without being ever freed. Address this issue by transferring ownership of the fence to the DMA reservation object, by calling dma_fence_put() right after dma_resv_add_fence(). The ffs_dma_fence then gets properly discarded after being signalled.
A flaw was found in the Linux kernel's USB gadget subsystem. Specifically, a DMA (Direct Memory Access) fence leak exists in the `f_fs` module's `ffs_dmabuf_transfer()` function. This issue causes `ffs_dma_fence` objects to be allocated without their initial reference being properly released. Repeated exploitation of this flaw could lead to a gradual memory leak, potentially resulting in a denial of service due to system resource exhaustion.
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_fs: Fix DMA fence leak In ffs_dmabuf_transfer(), a ffs_dma_fence object is kmalloc'd, with the underlying dma_fence later initialized by dma_fence_init(), which sets its kref counter to 1. Then, dma_resv_add_fence() gets a second reference, and a pointer to the ffs_dma_fence is passed as the usb_request's "context" field. The dma-resv mechanism will manage the second reference, but the first reference is never properly released; the ffs_dmabuf_cleanup() function decreases the reference count, but only to balance with the reference grab in ffs_dmabuf_signal_done(). The code will then slowly leak memory as more ffs_dma_fence objects are created without being ever freed. Address this issue by transferring ownership of the fence to the DMA reservation object, by calling dma_fence_put() right after dma_resv_add_fence(). The ffs_dma_fence then gets properly discarded after being signalled.
In the Linux kernel, the following vulnerability has been resolved: u ...
EPSS