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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Quentin Monnet <quentin@isovalent.com>,
        Andrii Nakryiko <andrii@kernel.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.16 0117/1039] bpftool: Fix memory leak in prog_dump()
Date:   Mon, 24 Jan 2022 19:31:46 +0100
Message-Id: <20220124184129.076854913@linuxfoundation.org>
In-Reply-To: <20220124184125.121143506@linuxfoundation.org>
References: <20220124184125.121143506@linuxfoundation.org>
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From: Quentin Monnet <quentin@isovalent.com>

[ Upstream commit ebbd7f64a3fbe9e0f235e39fc244ee9735e2a52a ]

Following the extraction of prog_dump() from do_dump(), the struct btf
allocated in prog_dump() is no longer freed on error; the struct
bpf_prog_linfo is not freed at all. Make sure we release them before
exiting the function.

Fixes: ec2025095cf6 ("bpftool: Match several programs with same tag")
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211110114632.24537-2-quentin@isovalent.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/bpf/bpftool/prog.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 515d229526026..6ccd17b8eb560 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -639,8 +639,8 @@ prog_dump(struct bpf_prog_info *info, enum dump_mode mode,
 	char func_sig[1024];
 	unsigned char *buf;
 	__u32 member_len;
+	int fd, err = -1;
 	ssize_t n;
-	int fd;
 
 	if (mode == DUMP_JITED) {
 		if (info->jited_prog_len == 0 || !info->jited_prog_insns) {
@@ -679,7 +679,7 @@ prog_dump(struct bpf_prog_info *info, enum dump_mode mode,
 		if (fd < 0) {
 			p_err("can't open file %s: %s", filepath,
 			      strerror(errno));
-			return -1;
+			goto exit_free;
 		}
 
 		n = write(fd, buf, member_len);
@@ -687,7 +687,7 @@ prog_dump(struct bpf_prog_info *info, enum dump_mode mode,
 		if (n != (ssize_t)member_len) {
 			p_err("error writing output file: %s",
 			      n < 0 ? strerror(errno) : "short write");
-			return -1;
+			goto exit_free;
 		}
 
 		if (json_output)
@@ -701,7 +701,7 @@ prog_dump(struct bpf_prog_info *info, enum dump_mode mode,
 						     info->netns_ino,
 						     &disasm_opt);
 			if (!name)
-				return -1;
+				goto exit_free;
 		}
 
 		if (info->nr_jited_func_lens && info->jited_func_lens) {
@@ -796,9 +796,12 @@ prog_dump(struct bpf_prog_info *info, enum dump_mode mode,
 		kernel_syms_destroy(&dd);
 	}
 
-	btf__free(btf);
+	err = 0;
 
-	return 0;
+exit_free:
+	btf__free(btf);
+	bpf_prog_linfo__free(prog_linfo);
+	return err;
 }
 
 static int do_dump(int argc, char **argv)
-- 
2.34.1