[PATCH 5.16 0117/1039] bpftool: Fix memory leak in prog_dump()

From: Greg Kroah-Hartman
Date: Mon Jan 24 2022 - 16:33:51 EST


From: Quentin Monnet <quentin@xxxxxxxxxxxxx>

[ 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@xxxxxxxxxxxxx>
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Link: https://lore.kernel.org/bpf/20211110114632.24537-2-quentin@xxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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