| From 9c32ccbadfadb2dc22cf4bb5641d4caf87f645e0 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Mon, 10 Nov 2025 14:21:18 +0100 |
| Subject: lib/vsprintf: Check pointer before dereferencing in time_and_date() |
| |
| From: Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
| |
| [ Upstream commit 372a12bd5df0199aa234eaf8ef31ed7ecd61d40f ] |
| |
| The pointer may be invalid when gets to the printf(). In particular |
| the time_and_date() dereferencing it in some cases without checking. |
| |
| Move the check from rtc_str() to time_and_date() to cover all cases. |
| |
| Fixes: 7daac5b2fdf8 ("lib/vsprintf: Print time64_t in human readable format") |
| Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
| Reviewed-by: Petr Mladek <pmladek@suse.com> |
| Link: https://patch.msgid.link/20251110132118.4113976-1-andriy.shevchenko@linux.intel.com |
| Signed-off-by: Petr Mladek <pmladek@suse.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| lib/vsprintf.c | 6 +++--- |
| 1 file changed, 3 insertions(+), 3 deletions(-) |
| |
| diff --git a/lib/vsprintf.c b/lib/vsprintf.c |
| index 90372391ce908..b643012ae47f6 100644 |
| --- a/lib/vsprintf.c |
| +++ b/lib/vsprintf.c |
| @@ -1829,9 +1829,6 @@ char *rtc_str(char *buf, char *end, const struct rtc_time *tm, |
| bool raw = false; |
| int count = 2; |
| |
| - if (check_pointer(&buf, end, tm, spec)) |
| - return buf; |
| - |
| switch (fmt[count]) { |
| case 'd': |
| have_t = false; |
| @@ -1886,6 +1883,9 @@ static noinline_for_stack |
| char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec, |
| const char *fmt) |
| { |
| + if (check_pointer(&buf, end, ptr, spec)) |
| + return buf; |
| + |
| switch (fmt[1]) { |
| case 'R': |
| return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt); |
| -- |
| 2.51.0 |
| |
