Fiche vulnérabilité
CVE-2026-64328 : faille moyenne linux linux kernel (CVSS 5.5)
Description
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.
En bref
- Sévérité
- Moyenne (CVSS 5.5)
- Vecteur CVSS
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Exploitation active
- Non signalée par la CISA
- Publication
- 25 juil. 2026
- Dernière mise à jour
- 4 sept. 2026
Produits concernés
- linux linux kernel