Tomoyo uses an open-coded version of time_to_tm() to create a timestamp from the current time as read by get_seconds(). This will overflow and give wrong results on 32-bit systems in 2038.

To correct this, this changes the code to use ktime_get_real_seconds() and the generic time64_to_tm() function that are both y2038-safe. Using the library function avoids adding an expensive 64-bit division in this code and can benefit from any optimizations we do in common code.

Signed-off-by: Arnd Bergmann arnd@arndb.de --- security/tomoyo/audit.c | 2 +- security/tomoyo/common.c | 4 ++-- security/tomoyo/common.h | 2 +- security/tomoyo/util.c | 39 +++++++++------------------------------ 4 files changed, 13 insertions(+), 34 deletions(-)

diff --git a/security/tomoyo/audit.c b/security/tomoyo/audit.c index 3ffa4f5509d8..a51edfbe593b 100644 --- a/security/tomoyo/audit.c +++ b/security/tomoyo/audit.c @@ -156,7 +156,7 @@ static char *tomoyo_print_header(struct tomoyo_request_info *r) if (!buffer) return NULL;

- tomoyo_convert_time(get_seconds(), &stamp); + tomoyo_convert_time(ktime_get_real_seconds(), &stamp);

pos = snprintf(buffer, tomoyo_buffer_len - 1, "#%04u/%02u/%02u %02u:%02u:%02u# profile=%u mode=%s " diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c index e0fb75052550..c19970db89c4 100644 --- a/security/tomoyo/common.c +++ b/security/tomoyo/common.c @@ -2256,7 +2256,7 @@ static const char * const tomoyo_memory_headers[TOMOYO_MAX_MEMORY_STAT] = { /* Timestamp counter for last updated. */ static unsigned int tomoyo_stat_updated[TOMOYO_MAX_POLICY_STAT]; /* Counter for number of updates. */ -static unsigned int tomoyo_stat_modified[TOMOYO_MAX_POLICY_STAT]; +static time64_t tomoyo_stat_modified[TOMOYO_MAX_POLICY_STAT];

/** * tomoyo_update_stat - Update statistic counters. @@ -2271,7 +2271,7 @@ void tomoyo_update_stat(const u8 index) * I don't use atomic operations because race condition is not fatal. */ tomoyo_stat_updated[index]++; - tomoyo_stat_modified[index] = get_seconds(); + tomoyo_stat_modified[index] = ktime_get_real_seconds(); }

/** diff --git a/security/tomoyo/common.h b/security/tomoyo/common.h index 361e7a284699..d9628d1635b2 100644 --- a/security/tomoyo/common.h +++ b/security/tomoyo/common.h @@ -1036,7 +1036,7 @@ void tomoyo_check_acl(struct tomoyo_request_info *r, bool (*check_entry) (struct tomoyo_request_info *, const struct tomoyo_acl_info *)); void tomoyo_check_profile(void); -void tomoyo_convert_time(time_t time, struct tomoyo_time *stamp); +void tomoyo_convert_time(time64_t time, struct tomoyo_time *stamp); void tomoyo_del_condition(struct list_head *element); void tomoyo_fill_path_info(struct tomoyo_path_info *ptr); void tomoyo_get_attributes(struct tomoyo_obj_info *obj); diff --git a/security/tomoyo/util.c b/security/tomoyo/util.c index 848317fea704..db7a978ab4a4 100644 --- a/security/tomoyo/util.c +++ b/security/tomoyo/util.c @@ -86,38 +86,17 @@ const u8 tomoyo_index2category[TOMOYO_MAX_MAC_INDEX] = { * @stamp: Pointer to "struct tomoyo_time". * * Returns nothing. - * - * This function does not handle Y2038 problem. */ -void tomoyo_convert_time(time_t time, struct tomoyo_time *stamp) +void tomoyo_convert_time(time64_t time64, struct tomoyo_time *stamp) { - static const u16 tomoyo_eom[2][12] = { - { 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 }, - { 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 } - }; - u16 y; - u8 m; - bool r; - stamp->sec = time % 60; - time /= 60; - stamp->min = time % 60; - time /= 60; - stamp->hour = time % 24; - time /= 24; - for (y = 1970; ; y++) { - const unsigned short days = (y & 3) ? 365 : 366; - if (time < days) - break; - time -= days; - } - r = (y & 3) == 0; - for (m = 0; m < 11 && time >= tomoyo_eom[r][m]; m++) - ; - if (m) - time -= tomoyo_eom[r][m - 1]; - stamp->year = y; - stamp->month = ++m; - stamp->day = ++time; + struct tm tm; + time64_to_tm(time64, 0, &tm); + stamp->sec = tm.tm_sec; + stamp->min = tm.tm_min; + stamp->hour = tm.tm_hour; + stamp->day = tm.tm_mday; + stamp->month = tm.tm_mon + 1; + stamp->year = tm.tm_year - (1970 - 1900); }

/**