Re: [PATCH v2 2/2] trace: kdb: Replace simple_strtoul with kstrtoul in kdb_ftdump
From: Doug Anderson <dianders@chromium.org>
Date: 2024-10-25 22:31:56
Also in:
linux-kernel-mentees, lkml
Hi, On Mon, Oct 21, 2024 at 2:17 PM 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 Signed-off-by: Yuran Pereira <redacted> Signed-off-by: Nir Lichtman <redacted>
I have the same comments as patch #1 about authorship and noting what you changed.
quoted hunk ↗ jump to hunk
--- 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))
FWIW, this is still changing the indentation of the second line in a way that makes it worse list like v1 did [1]. :-P The "!" in "!cpu_" should line up right under the "e" in "err". That's a pretty tiny nit, so I'm OK with: Reviewed-by: Douglas Anderson <dianders@chromium.org> When sending v3 you'd want to keep Masami's Acked-by tag and my Reviewed-by tag. They should go just above your Signed-off-by tag.