Currently, alloc_skb_with_frags() will only fill (MAX_SKB_FRAGS - 1) slots. I think it should use all MAX_SKB_FRAGS slots, as callers of alloc_skb_with_frags() will size their allocation of frags based on MAX_SKB_FRAGS. This issue was discovered via a test patch that sets 'order' to 0 in alloc_skb_with_frags(), which effectively tests/simulates high fragmentation. In this case sendmsg() on unix sockets will fail every time for large allocations. If the PAGE_SIZE is 4K, then data_len will request 68K or 17 pages, but alloc_skb_with_frags() can only allocate 64K in this case or 16 pages. Fixes: 09c2c90705bb ("net: allow alloc_skb_with_frags() to allocate bigger packets") Signed-off-by: Jason Baron --- Changes: v2: Add Fixes: tag --- net/core/skbuff.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 23b776cd9879..df942aca0617 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -6669,7 +6669,7 @@ struct sk_buff *alloc_skb_with_frags(unsigned long header_len, return NULL; while (data_len) { - if (nr_frags == MAX_SKB_FRAGS - 1) + if (nr_frags == MAX_SKB_FRAGS) goto failure; while (order && PAGE_ALIGN(data_len) < (PAGE_SIZE << order)) order--; -- 2.25.1