diff options
| author | Jenny Guanni Qu <qguanni@gmail.com> | 2026-03-12 17:59:49 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-03-25 13:06:07 +0300 |
| commit | 262beb78e95e735f2c38ec0ebf87f8d7871159c7 (patch) | |
| tree | 1638e821cd68e6c1c17fd209bd2ec73221c66a3b /net | |
| parent | 63b8097cea1923fe82cd598068d0796da8c015ec (diff) | |
| download | linux-262beb78e95e735f2c38ec0ebf87f8d7871159c7.tar.xz | |
netfilter: xt_time: use unsigned int for monthday bit shift
[ Upstream commit 00050ec08cecfda447e1209b388086d76addda3a ]
The monthday field can be up to 31, and shifting a signed integer 1
by 31 positions (1 << 31) is undefined behavior in C, as the result
overflows a 32-bit signed int. Use 1U to ensure well-defined behavior
for all valid monthday values.
Change the weekday shift to 1U as well for consistency.
Fixes: ee4411a1b1e0 ("[NETFILTER]: x_tables: add xt_time match")
Reported-by: Klaudia Kloc <klaudia@vidocsecurity.com>
Reported-by: Dawid Moczadło <dawid@vidocsecurity.com>
Tested-by: Jenny Guanni Qu <qguanni@gmail.com>
Signed-off-by: Jenny Guanni Qu <qguanni@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/xt_time.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/netfilter/xt_time.c b/net/netfilter/xt_time.c index 6aa12d0f54e2..61de85e02a40 100644 --- a/net/netfilter/xt_time.c +++ b/net/netfilter/xt_time.c @@ -227,13 +227,13 @@ time_mt(const struct sk_buff *skb, struct xt_action_param *par) localtime_2(¤t_time, stamp); - if (!(info->weekdays_match & (1 << current_time.weekday))) + if (!(info->weekdays_match & (1U << current_time.weekday))) return false; /* Do not spend time computing monthday if all days match anyway */ if (info->monthdays_match != XT_TIME_ALL_MONTHDAYS) { localtime_3(¤t_time, stamp); - if (!(info->monthdays_match & (1 << current_time.monthday))) + if (!(info->monthdays_match & (1U << current_time.monthday))) return false; } |