CVE-2026-90115xsk: fix NULL pointer dereference in __xsk_rcv()

Official description

In the Linux kernel, the following vulnerability has been resolved: xsk: fix NULL pointer dereference in __xsk_rcv() In the __xsk_rcv() multi-buffer path, xsk_buff_alloc() is called in a loop without checking its return value. xsk_buff_can_alloc() only counts fill queue entries without validating their addresses, so it can succeed while xsk_buff_alloc() rejects all remaining entries and returns NULL. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000 KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:__xsk_rcv+0x426/0xc20 (net/xdp/xsk.c:350) Call Trace: xsk_generic_rcv+0x26d/0x5f0 xdp_do_generic_redirect+0x3c5/0xcf0 do_xdp_generic+0x92f/0xe70 __netif_receive_skb_core.constprop.0+0xf7e/0x2b30 Fix this with a two-stage transaction. First allocate and stage all buffers required for the packet, recycling all staged buffers with xsk_buff_free() if any allocation fails. Only after this stage succeeds, copy the data, reserve the RX descriptors, and release the buffers in an error-free loop.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/aaebce297efc3e3dccb98a6ff838cfaa47db08db
• https://git.kernel.org/stable/c/60d7d3559ce66e227e195e9463cdfed8077c8659
• https://git.kernel.org/stable/c/214fb79b0379cb0214905632a2537c0c33f594eb
• https://git.kernel.org/stable/c/8341bd3ff126d85bc8c4ed52eedcaa5b1a65f194
• https://git.kernel.org/stable/c/e37b2abca80473e106176e41712a369fd2f72117