Re: [PATCH v2 2/2] trace: kdb: Replace simple_strtoul with kstrtoul in kdb_ftdump
From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Date: 2024-10-23 08:49:47
Also in:
linux-kernel-mentees, lkml
On Mon, 21 Oct 2024 21:17:24 +0000 Nir Lichtman [off-list ref] wrote:
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
Looks good to me. Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Thank you,
quoted hunk ↗ jump to hunk
Signed-off-by: Yuran Pereira <redacted> Signed-off-by: Nir Lichtman <redacted> --- kernel/trace/trace_kdb.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-)diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c index 59857a1ee44c..eadda6e05526 100644 --- a/kernel/trace/trace_kdb.c +++ b/kernel/trace/trace_kdb.c@@ -96,23 +96,20 @@ 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 || - !cpu_online(cpu_file)) + err = kstrtol(argv[2], 0, &cpu_file); + if (err || cpu_file >= NR_CPUS || cpu_file < 0 || + !cpu_online(cpu_file)) return KDB_BADINT; } else { cpu_file = RING_BUFFER_ALL_CPUS;-- 2.39.2
-- Masami Hiramatsu (Google) [off-list ref]