6.16-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ian Rogers irogers@google.com
[ Upstream commit 478272d1cdd9959a6d638e9d81f70642f04290c9 ]
FILENAME_MAX is often PATH_MAX (4kb), far more than needed for the /proc path. Make the buffer size sufficient for the maximum integer plus "/proc/" and "/status" with a '\0' terminator.
Fixes: 5ce42b5de461 ("tools subcmd: Add non-waitpid check_if_command_finished()") Signed-off-by: Ian Rogers irogers@google.com Link: https://lore.kernel.org/r/20250717150855.1032526-1-irogers@google.com Signed-off-by: Namhyung Kim namhyung@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/lib/subcmd/run-command.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/tools/lib/subcmd/run-command.c b/tools/lib/subcmd/run-command.c index 0a764c25c384..b7510f83209a 100644 --- a/tools/lib/subcmd/run-command.c +++ b/tools/lib/subcmd/run-command.c @@ -5,6 +5,7 @@ #include <ctype.h> #include <fcntl.h> #include <string.h> +#include <linux/compiler.h> #include <linux/string.h> #include <errno.h> #include <sys/wait.h> @@ -216,10 +217,20 @@ static int wait_or_whine(struct child_process *cmd, bool block) return result; }
+/* + * Conservative estimate of number of characaters needed to hold an a decoded + * integer, assume each 3 bits needs a character byte and plus a possible sign + * character. + */ +#ifndef is_signed_type +#define is_signed_type(type) (((type)(-1)) < (type)1) +#endif +#define MAX_STRLEN_TYPE(type) (sizeof(type) * 8 / 3 + (is_signed_type(type) ? 1 : 0)) + int check_if_command_finished(struct child_process *cmd) { #ifdef __linux__ - char filename[FILENAME_MAX + 12]; + char filename[6 + MAX_STRLEN_TYPE(typeof(cmd->pid)) + 7 + 1]; char status_line[256]; FILE *status_file;
@@ -227,7 +238,7 @@ int check_if_command_finished(struct child_process *cmd) * Check by reading /proc/<pid>/status as calling waitpid causes * stdout/stderr to be closed and data lost. */ - sprintf(filename, "/proc/%d/status", cmd->pid); + sprintf(filename, "/proc/%u/status", cmd->pid); status_file = fopen(filename, "r"); if (status_file == NULL) { /* Open failed assume finish_command was called. */