From: Xu Kuohai xukuohai@huawei.com
In the arm64 version of parse_usdt_arg(), when sscanf returns 2, reg_name is allocated but not freed. Fix it.
Fixes: 0f8619929c57 ("libbpf: Usdt aarch64 arg parsing support") Signed-off-by: Xu Kuohai xukuohai@huawei.com --- tools/lib/bpf/usdt.c | 59 +++++++++++++++++++++++++------------------- 1 file changed, 33 insertions(+), 26 deletions(-)
diff --git a/tools/lib/bpf/usdt.c b/tools/lib/bpf/usdt.c index e83b497c2245..f3b5be7415b5 100644 --- a/tools/lib/bpf/usdt.c +++ b/tools/lib/bpf/usdt.c @@ -1351,8 +1351,10 @@ static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec char *reg_name = NULL; int arg_sz, len, reg_off; long off; + int ret;
- if (sscanf(arg_str, " %d @ [ %m[a-z0-9], %ld ] %n", &arg_sz, ®_name, &off, &len) == 3) { + ret = sscanf(arg_str, " %d @ [ %m[a-z0-9], %ld ] %n", &arg_sz, ®_name, &off, &len); + if (ret == 3) { /* Memory dereference case, e.g., -4@[sp, 96] */ arg->arg_type = USDT_ARG_REG_DEREF; arg->val_off = off; @@ -1361,32 +1363,37 @@ static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec 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, ®_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; - } else if (sscanf(arg_str, " %d @ %ld %n", &arg_sz, &off, &len) == 2) { - /* Constant value case, e.g., 4@5 */ - 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, ®_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; } else { - pr_warn("usdt: unrecognized arg #%d spec '%s'\n", arg_num, arg_str); - return -EINVAL; + if (ret == 2) + free(reg_name); + + if (sscanf(arg_str, " %d @ [ %m[a-z0-9] ] %n", &arg_sz, ®_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; + } else if (sscanf(arg_str, " %d @ %ld %n", &arg_sz, &off, &len) == 2) { + /* Constant value case, e.g., 4@5 */ + 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, ®_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; + } else { + pr_warn("usdt: unrecognized arg #%d spec '%s'\n", arg_num, arg_str); + return -EINVAL; + } }
arg->arg_signed = arg_sz < 0;