Description

In the Linux kernel, the following vulnerability has been resolved: net: tun: Fix memory leaks of napi_get_frags kmemleak reports after running test_progs: unreferenced object 0xffff8881b1672dc0 (size 232): comm "test_progs", pid 394388, jiffies 4354712116 (age 841.975s) hex dump (first 32 bytes): e0 84 d7 a8 81 88 ff ff 80 2c 67 b1 81 88 ff ff .........,g..... 00 40 c5 9b 81 88 ff ff 00 00 00 00 00 00 00 00 .@.............. backtrace: [] napi_skb_cache_get+0xd4/0x150 [] __napi_build_skb+0x15/0x50 [] __napi_alloc_skb+0x26e/0x540 [] napi_get_frags+0x59/0x140 [] tun_get_user+0x183d/0x3bb0 [tun] [] tun_chr_write_iter+0xc0/0x1b1 [tun] [] do_iter_readv_writev+0x19f/0x320 [] do_iter_write+0x135/0x630 [] vfs_writev+0x12e/0x440 [] do_writev+0x104/0x280 [] do_syscall_64+0x3b/0x90 [] entry_SYSCALL_64_after_hwframe+0x63/0xcd The issue occurs in the following scenarios: tun_get_user() napi_gro_frags() napi_frags_finish() case GRO_NORMAL: gro_normal_one() list_add_tail(&skb->list, &napi->rx_list); rx_count < READ_ONCE(gro_normal_batch), rx_list is not empty <-- not ask to complete the gro work, will cause memory leaks in <-- following tun_napi_del() ... tun_napi_del() netif_napi_del() __netif_napi_del() rx_list is not empty, which caused memory leaks To fix, add napi_complete() after napi_gro_frags().