From 986deb297d48ae7039ab975f00c14f0bfe069125 Mon Sep 17 00:00:00 2001 From: Hou Tao Date: Thu, 12 Sep 2024 09:28:45 +0800 Subject: [PATCH] bpf: Call the missed kfree() when there is no special field in btf Call the missed kfree() in btf_parse_struct_metas() when there is no special field in btf, otherwise will get the following kmemleak report: unreferenced object 0xffff888101033620 (size 8): comm "test_progs", pid 604, jiffies 4295127011 ...... backtrace (crc e77dc444): [<00000000186f90f3>] kmemleak_alloc+0x4b/0x80 [<00000000ac8e9c4d>] __kmalloc_cache_noprof+0x2a1/0x310 [<00000000d99d68d6>] btf_new_fd+0x72d/0xe90 [<00000000f010b7f8>] __sys_bpf+0xec3/0x2410 [<00000000e077ed6f>] __x64_sys_bpf+0x1f/0x30 [<00000000a12f9e55>] x64_sys_call+0x199/0x9f0 [<00000000f3029ea6>] do_syscall_64+0x3b/0xc0 [<000000005640913a>] entry_SYSCALL_64_after_hwframe+0x4b/0x53 Fixes: 7a851ecb1806 ("bpf: Search for kptrs in prog BTF structs") Signed-off-by: Hou Tao Acked-by: Jiri Olsa Link: https://lore.kernel.org/r/20240912012845.3458483-3-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov --- kernel/bpf/btf.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 59b4f7265761c9..31eae516f70114 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -5572,8 +5572,10 @@ btf_parse_struct_metas(struct bpf_verifier_log *log, struct btf *btf) aof->ids[aof->cnt++] = i; } - if (!aof->cnt) + if (!aof->cnt) { + kfree(aof); return NULL; + } sort(&aof->ids, aof->cnt, sizeof(aof->ids[0]), btf_id_cmp_func, NULL); for (i = 1; i < n; i++) {