diff options
| author | Yuan Tan <tanyuan98@outlook.com> | 2026-03-09 03:41:46 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-03-19 16:08:18 +0100 |
| commit | f5ef97c13165542480a6ffdbe6f09f40bbb7cbf1 (patch) | |
| tree | bcbca91f2394f834e6c9991cdccb67fb5eb3f87c /net | |
| parent | 05018cd9370f77bb18fbf6e15ff33c7a06f10b3c (diff) | |
netfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels
[ Upstream commit 329f0b9b48ee6ab59d1ab72fef55fe8c6463a6cf ]
IDLETIMER revision 0 rules reuse existing timers by label and always call
mod_timer() on timer->timer.
If the label was created first by revision 1 with XT_IDLETIMER_ALARM,
the object uses alarm timer semantics and timer->timer is never initialized.
Reusing that object from revision 0 causes mod_timer() on an uninitialized
timer_list, triggering debugobjects warnings and possible panic when
panic_on_warn=1.
Fix this by rejecting revision 0 rule insertion when an existing timer with
the same label is of ALARM type.
Fixes: 68983a354a65 ("netfilter: xtables: Add snapshot of hardidletimer target")
Co-developed-by: Yifan Wu <yifanwucs@gmail.com>
Signed-off-by: Yifan Wu <yifanwucs@gmail.com>
Co-developed-by: Juefei Pu <tomapufckgml@gmail.com>
Signed-off-by: Juefei Pu <tomapufckgml@gmail.com>
Signed-off-by: Yuan Tan <tanyuan98@outlook.com>
Signed-off-by: Xin Liu <dstsmallbird@foxmail.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_IDLETIMER.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/net/netfilter/xt_IDLETIMER.c b/net/netfilter/xt_IDLETIMER.c index d73957592c9d..bb7af92ac82a 100644 --- a/net/netfilter/xt_IDLETIMER.c +++ b/net/netfilter/xt_IDLETIMER.c @@ -318,6 +318,12 @@ static int idletimer_tg_checkentry(const struct xt_tgchk_param *par) info->timer = __idletimer_tg_find_by_label(info->label); if (info->timer) { + if (info->timer->timer_type & XT_IDLETIMER_ALARM) { + pr_debug("Adding/Replacing rule with same label and different timer type is not allowed\n"); + mutex_unlock(&list_mutex); + return -EINVAL; + } + info->timer->refcnt++; mod_timer(&info->timer->timer, secs_to_jiffies(info->timeout) + jiffies); |