In the Linux kernel, the following vulnerability has been resolved:

liquidio: Adjust a NULL pointer handling path in lio_vf_rep_copy_packet

In lio_vf_rep_copy_packet() pg_info->page is compared to a NULL value,
but then it is unconditionally passed to skb_add_rx_frag() which looks
strange and could lead to null pointer dereference.

lio_vf_rep_copy_packet() call trace looks like:
	octeon_droq_process_packets
	 octeon_droq_fast_process_packets
	  octeon_droq_dispatch_pkt
	   octeon_create_recv_info
	    ...search in the dispatch_list...
	     ->disp_fn(rdisp->rinfo, ...)
	      lio_vf_rep_pkt_recv(struct octeon_recv_info *recv_info, ...)
In this path there is no code which sets pg_info->page to NULL.
So this check looks unneeded and doesn't solve potential problem.
But I guess the author had reason to add a check and I have no such card
and can't do real test.
In addition, the code in the function liquidio_push_packet() in
liquidio/lio_core.c does exactly the same.

Based on this, I consider the most acceptable compromise solution to
adjust this issue by moving skb_add_rx_frag() into conditional scope.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

kernel.org https://git.kernel.org/stable/c/87d6bdc006f0cbf297a3b2ad6e40ede4c3ee5dc2 [No types assigned]

kernel.org https://git.kernel.org/stable/c/a6f4d0ec170a46b5f453cacf55dff5989b42bbfa [No types assigned]

kernel.org https://git.kernel.org/stable/c/a86490a3712cc513113440a606a0e77130abd47c [No types assigned]

kernel.org https://git.kernel.org/stable/c/c44711b78608c98a3e6b49ce91678cd0917d5349 [No types assigned]

kernel.org https://git.kernel.org/stable/c/cbf18d8128a753cb632bef39470d19befd9c7347 [No types assigned]

kernel.org https://git.kernel.org/stable/c/dcc7440f32c7a26b067aff6e7d931ec593024a79 [No types assigned]

kernel.org https://git.kernel.org/stable/c/f1ab15a09492a5ae8ab1e2c35ba2cf9e150d25ee [No types assigned]

kernel.org https://git.kernel.org/stable/c/fd2b613bc4c508e55c1221c6595bb889812a4fea [No types assigned]