diff options
| author | Liu Dalin <liudalin@kylinsec.com.cn> | 2026-08-27 16:03:20 +0800 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2026-10-02 10:36:20 +0200 |
| commit | 32f04694fa87b8ac9fa58f9ceb2dc6cbc476e2a1 (patch) | |
| tree | 322db7beda0f254cb5189cd54cf19115a11cc738 /include | |
| parent | d41ee317c9907d714014d0d5e4726fbd6acf338e (diff) | |
| download | linux-next-32f04694fa87b8ac9fa58f9ceb2dc6cbc476e2a1.tar.gz linux-next-32f04694fa87b8ac9fa58f9ceb2dc6cbc476e2a1.zip | |
rtc: ftrtc010: fix integer overflow in time calculation
In ftrtc010_rtc_read_time() and ftrtc010_rtc_set_time(), all
variables (offset, days, hour, min, sec) are u32. The expression
"days * 86400 + hour * 3600 + min * 60 + sec" is evaluated in
32-bit arithmetic, which silently wraps around for dates beyond
approximately year 2106 (U32_MAX / 86400 ≈ 49710 days).
In ftrtc010_rtc_read_time(), perform the addition in 32-bit
arithmetic first to preserve two's complement wrapping for negative
offsets, then cast the result to timeu64_t. In
ftrtc010_rtc_set_time(), cast individual u32 operands to timeu64_t
before multiplication to prevent overflow in the right-hand side
of the offset calculation.
Fixes: 1d61d2592c1f ("rtc: gemini/ftrtc010: rename driver and symbols")
Assisted-by: Sashiko AI [static analysis]
Signed-off-by: Liu Dalin <liudalin@kylinsec.com.cn>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Tested-by: Liu Dalin <liudalin@kylinsec.com.cn>
Link: https://patch.msgid.link/42C8FBD59AA34EA9+20260827080320.3351155-4-liudalin@kylinsec.com.cn
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'include')
0 files changed, 0 insertions, 0 deletions