CVE-2026-31501net: ti: icssg-prueth: fix use-after-free of CPPI descriptor in RX path

Official description

In the Linux kernel, the following vulnerability has been resolved: net: ti: icssg-prueth: fix use-after-free of CPPI descriptor in RX path cppi5_hdesc_get_psdata() returns a pointer into the CPPI descriptor. In both emac_rx_packet() and emac_rx_packet_zc(), the descriptor is freed via k3_cppi_desc_pool_free() before the psdata pointer is used by emac_rx_timestamp(), which dereferences psdata[0] and psdata[1]. This constitutes a use-after-free on every received packet that goes through the timestamp path. Defer the descriptor free until after all accesses through the psdata pointer are complete. For emac_rx_packet(), move the free into the requeue label so both early-exit and success paths free the descriptor after all accesses are done. For emac_rx_packet_zc(), move the free to the end of the loop body after emac_dispatch_skb_zc() (which calls emac_rx_timestamp()) has returned.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/c516c2e06fe580b8d38de60cd407072a5de81506
• https://git.kernel.org/stable/c/d5827316debcb677679bb014885d7be92c410e11
• https://git.kernel.org/stable/c/eb8c426c9803beb171f89d15fea17505eb517714