The atoi() function does not perform error checking, which can lead to undefined behavior when parsing invalid or out-of-range strings. This can cause issues when parsing user-provided numerical inputs, such as signal numbers, PIDs, or CPU lists.
To address this, introduce a new strtoi() helper function that safely converts a string to an integer. This function validates the input and checks for overflows, returning a negative value on failure. Replace all calls to atoi() with the new strtoi() function and add proper error handling to make the parsing more robust and prevent potential issues. Signed-off-by: Wander Lairson Costa <[email protected]> --- tools/tracing/rtla/src/actions.c | 7 +++--- tools/tracing/rtla/src/utils.c | 40 ++++++++++++++++++++++++++++---- tools/tracing/rtla/src/utils.h | 2 ++ 3 files changed, 41 insertions(+), 8 deletions(-) diff --git a/tools/tracing/rtla/src/actions.c b/tools/tracing/rtla/src/actions.c index a4d0dc47e6aa1..e933c2c68b208 100644 --- a/tools/tracing/rtla/src/actions.c +++ b/tools/tracing/rtla/src/actions.c @@ -170,12 +170,13 @@ actions_parse(struct actions *self, const char *trigger, const char *tracefn) /* Takes two arguments, num (signal) and pid */ while (token != NULL) { if (strlen(token) > 4 && strncmp(token, "num=", 4) == 0) { - signal = atoi(token + 4); + if (strtoi(token + 4, &signal)) + return -1; } else if (strlen(token) > 4 && strncmp(token, "pid=", 4) == 0) { if (strncmp(token + 4, "parent", 7) == 0) pid = -1; - else - pid = atoi(token + 4); + else if (strtoi(token + 4, &pid)) + return -1; } else { /* Invalid argument */ return -1; diff --git a/tools/tracing/rtla/src/utils.c b/tools/tracing/rtla/src/utils.c index acf95afa25b5a..f3e129d17a82b 100644 --- a/tools/tracing/rtla/src/utils.c +++ b/tools/tracing/rtla/src/utils.c @@ -17,6 +17,7 @@ #include <fcntl.h> #include <sched.h> #include <stdio.h> +#include <limits.h> #include "utils.h" @@ -127,16 +128,18 @@ int parse_cpu_set(char *cpu_list, cpu_set_t *set) nr_cpus = sysconf(_SC_NPROCESSORS_CONF); for (p = cpu_list; *p; ) { - cpu = atoi(p); - if (cpu < 0 || (!cpu && *p != '0') || cpu >= nr_cpus) + if (strtoi(p, &cpu)) + goto err; + if (cpu < 0 || cpu >= nr_cpus) goto err; while (isdigit(*p)) p++; if (*p == '-') { p++; - end_cpu = atoi(p); - if (end_cpu < cpu || (!end_cpu && *p != '0') || end_cpu >= nr_cpus) + if (strtoi(p, &end_cpu)) + goto err; + if (end_cpu < cpu || end_cpu >= nr_cpus) goto err; while (isdigit(*p)) p++; @@ -337,6 +340,7 @@ int set_comm_sched_attr(const char *comm_prefix, struct sched_attr *attr) struct dirent *proc_entry; DIR *procfs; int retval; + int pid; if (strlen(comm_prefix) >= MAX_PATH) { err_msg("Command prefix is too long: %d < strlen(%s)\n", @@ -356,8 +360,12 @@ int set_comm_sched_attr(const char *comm_prefix, struct sched_attr *attr) if (!retval) continue; + if (strtoi(proc_entry->d_name, &pid)) { + err_msg("'%s' is not a valid pid", proc_entry->d_name); + goto out_err; + } /* procfs_is_workload_pid confirmed it is a pid */ - retval = __set_sched_attr(atoi(proc_entry->d_name), attr); + retval = __set_sched_attr(pid, attr); if (retval) { err_msg("Error setting sched attributes for pid:%s\n", proc_entry->d_name); goto out_err; @@ -1035,3 +1043,25 @@ char *strdup_fatal(const char *s) return p; } + +/* + * strtoi - convert string to integer with error checking + * + * Returns 0 on success, -1 if conversion fails or result is out of int range. + */ +int strtoi(const char *s, int *res) +{ + char *end_ptr; + long lres; + + if (!*s) + return -1; + + errno = 0; + lres = strtol(s, &end_ptr, 0); + if (errno || *end_ptr || lres > INT_MAX || lres < INT_MIN) + return -1; + + *res = (int) lres; + return 0; +} diff --git a/tools/tracing/rtla/src/utils.h b/tools/tracing/rtla/src/utils.h index 0ed2c7275f2c5..efbf798650306 100644 --- a/tools/tracing/rtla/src/utils.h +++ b/tools/tracing/rtla/src/utils.h @@ -3,6 +3,7 @@ #include <stdint.h> #include <time.h> #include <sched.h> +#include <stdbool.h> /* * '18446744073709551615\0' @@ -85,6 +86,7 @@ static inline int set_deepest_cpu_idle_state(unsigned int cpu, unsigned int stat static inline int have_libcpupower_support(void) { return 0; } #endif /* HAVE_LIBCPUPOWER_SUPPORT */ int auto_house_keeping(cpu_set_t *monitored_cpus); +__attribute__((__warn_unused_result__)) int strtoi(const char *s, int *res); #define ns_to_usf(x) (((double)x/1000)) #define ns_to_per(total, part) ((part * 100) / (double)total) -- 2.52.0
