[PATCH 5.10/5.15/6.1 0/1] net: prevent mss overflow in skb_segment()

Syzkaller reports NULL pointer dereference issue at skb_segment() in 5.10/5.15/6.1 stable releases. The problem has been fixed by the following patch which can be cleanly applied to 5.10/5.15/6.1 branches.

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