From 0c10cc2435115c36dcb611f8e1ed99ba6de6f17f Mon Sep 17 00:00:00 2001 From: Yuran Pereira Date: Mon, 28 Oct 2024 19:21:00 +0000 Subject: [PATCH] trace: kdb: Replace simple_strtoul with kstrtoul in kdb_ftdump The function simple_strtoul performs no error checking in scenarios where the input value overflows the intended output variable. This results in this function successfully returning, even when the output does not match the input string (aka the function returns successfully even when the result is wrong). Or as it was mentioned [1], "...simple_strtol(), simple_strtoll(), simple_strtoul(), and simple_strtoull() functions explicitly ignore overflows, which may lead to unexpected results in callers." Hence, the use of those functions is discouraged. This patch replaces all uses of the simple_strtoul with the safer alternatives kstrtoint and kstrtol. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#simple-strtol-simple-strtoll-simple-strtoul-simple-strtoull Signed-off-by: Yuran Pereira Reviewed-by: Douglas Anderson Acked-by: Masami Hiramatsu (Google) Acked-by: Steven Rostedt (Google) [nir: style fixes] Signed-off-by: Nir Lichtman Link: https://lore.kernel.org/r/20241028192100.GB918454@lichtman.org Signed-off-by: Daniel Thompson --- kernel/trace/trace_kdb.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c index 59857a1ee44c..1e72d20b3c2f 100644 --- a/kernel/trace/trace_kdb.c +++ b/kernel/trace/trace_kdb.c @@ -96,22 +96,19 @@ static int kdb_ftdump(int argc, const char **argv) { int skip_entries = 0; long cpu_file; - char *cp; + int err; int cnt; int cpu; if (argc > 2) return KDB_ARGCOUNT; - if (argc) { - skip_entries = simple_strtol(argv[1], &cp, 0); - if (*cp) - skip_entries = 0; - } + if (argc && kstrtoint(argv[1], 0, &skip_entries)) + return KDB_BADINT; if (argc == 2) { - cpu_file = simple_strtol(argv[2], &cp, 0); - if (*cp || cpu_file >= NR_CPUS || cpu_file < 0 || + err = kstrtol(argv[2], 0, &cpu_file); + if (err || cpu_file >= NR_CPUS || cpu_file < 0 || !cpu_online(cpu_file)) return KDB_BADINT; } else {