libbpf: Fix memory leak in parse_usdt_arg()

In the arm64 version of parse_usdt_arg(), when sscanf returns 2, reg_name
is allocated but not freed. Fix it.

Fixes: 0f8619929c ("libbpf: Usdt aarch64 arg parsing support")
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/bpf/20221011120108.782373-3-xukuohai@huaweicloud.com
This commit is contained in:
Xu Kuohai 2022-10-11 08:01:04 -04:00 committed by Andrii Nakryiko
parent 93c660ca40
commit 0dc9254e03

View File

@ -1348,25 +1348,23 @@ static int calc_pt_regs_off(const char *reg_name)
static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec *arg)
{
char *reg_name = NULL;
char reg_name[16];
int arg_sz, len, reg_off;
long off;
if (sscanf(arg_str, " %d @ \[ %m[a-z0-9], %ld ] %n", &arg_sz, &reg_name, &off, &len) == 3) {
if (sscanf(arg_str, " %d @ \[ %15[a-z0-9], %ld ] %n", &arg_sz, reg_name, &off, &len) == 3) {
/* Memory dereference case, e.g., -4@[sp, 96] */
arg->arg_type = USDT_ARG_REG_DEREF;
arg->val_off = off;
reg_off = calc_pt_regs_off(reg_name);
free(reg_name);
if (reg_off < 0)
return reg_off;
arg->reg_off = reg_off;
} else if (sscanf(arg_str, " %d @ \[ %m[a-z0-9] ] %n", &arg_sz, &reg_name, &len) == 2) {
} else if (sscanf(arg_str, " %d @ \[ %15[a-z0-9] ] %n", &arg_sz, reg_name, &len) == 2) {
/* Memory dereference case, e.g., -4@[sp] */
arg->arg_type = USDT_ARG_REG_DEREF;
arg->val_off = 0;
reg_off = calc_pt_regs_off(reg_name);
free(reg_name);
if (reg_off < 0)
return reg_off;
arg->reg_off = reg_off;
@ -1375,12 +1373,11 @@ static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec
arg->arg_type = USDT_ARG_CONST;
arg->val_off = off;
arg->reg_off = 0;
} else if (sscanf(arg_str, " %d @ %m[a-z0-9] %n", &arg_sz, &reg_name, &len) == 2) {
} else if (sscanf(arg_str, " %d @ %15[a-z0-9] %n", &arg_sz, reg_name, &len) == 2) {
/* Register read case, e.g., -8@x4 */
arg->arg_type = USDT_ARG_REG;
arg->val_off = 0;
reg_off = calc_pt_regs_off(reg_name);
free(reg_name);
if (reg_off < 0)
return reg_off;
arg->reg_off = reg_off;