From: Steven Rostedt <rost...@goodmis.org> The function dyn_event_release() uses argv_split() which must be freed via argv_free(). It contains several error paths that do a goto out to call argv_free() for cleanup. This makes the code complex and error prone.
Create a new __free() directive __free(argv_free) that will call argv_free() for data allocated with argv_split(), and use it in the dyn_event_release() function. Cc: Kees Cook <k...@kernel.org> Cc: Andy Shevchenko <a...@kernel.org> Cc: linux-harden...@vger.kernel.org Signed-off-by: Steven Rostedt (Google) <rost...@goodmis.org> --- Changes since v1: https://lore.kernel.org/all/20241219201346.029319...@goodmis.org/ - Moved include of cleanup.h up to be more alphabetically ordered include/linux/string.h | 3 +++ kernel/trace/trace_dynevent.c | 23 +++++++---------------- 2 files changed, 10 insertions(+), 16 deletions(-) diff --git a/include/linux/string.h b/include/linux/string.h index 493ac4862c77..86d5d352068b 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -4,6 +4,7 @@ #include <linux/args.h> #include <linux/array_size.h> +#include <linux/cleanup.h> /* for DEFINE_FREE() */ #include <linux/compiler.h> /* for inline */ #include <linux/types.h> /* for size_t */ #include <linux/stddef.h> /* for NULL */ @@ -312,6 +313,8 @@ extern void *kmemdup_array(const void *src, size_t count, size_t element_size, g extern char **argv_split(gfp_t gfp, const char *str, int *argcp); extern void argv_free(char **argv); +DEFINE_FREE(argv_free, char **, if (!IS_ERR_OR_NULL(_T)) argv_free(_T)) + /* lib/cmdline.c */ extern int get_option(char **str, int *pint); extern char *get_options(const char *str, int nints, int *ints); diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c index 4376887e0d8a..a322e4f249a5 100644 --- a/kernel/trace/trace_dynevent.c +++ b/kernel/trace/trace_dynevent.c @@ -74,24 +74,19 @@ int dyn_event_release(const char *raw_command, struct dyn_event_operations *type struct dyn_event *pos, *n; char *system = NULL, *event, *p; int argc, ret = -ENOENT; - char **argv; + char **argv __free(argv_free) = argv_split(GFP_KERNEL, raw_command, &argc); - argv = argv_split(GFP_KERNEL, raw_command, &argc); if (!argv) return -ENOMEM; if (argv[0][0] == '-') { - if (argv[0][1] != ':') { - ret = -EINVAL; - goto out; - } + if (argv[0][1] != ':') + return -EINVAL; event = &argv[0][2]; } else { event = strchr(argv[0], ':'); - if (!event) { - ret = -EINVAL; - goto out; - } + if (!event) + return -EINVAL; event++; } @@ -101,10 +96,8 @@ int dyn_event_release(const char *raw_command, struct dyn_event_operations *type event = p + 1; *p = '\0'; } - if (!system && event[0] == '\0') { - ret = -EINVAL; - goto out; - } + if (!system && event[0] == '\0') + return -EINVAL; mutex_lock(&event_mutex); for_each_dyn_event_safe(pos, n) { @@ -120,8 +113,6 @@ int dyn_event_release(const char *raw_command, struct dyn_event_operations *type } tracing_reset_all_online_cpus(); mutex_unlock(&event_mutex); -out: - argv_free(argv); return ret; } -- 2.45.2
