[PATCH net-next 0/2] ipv4: igmp: annotate diagnostic procfs data races

From: Yuyang Huang

Date: Sat May 30 2026 - 23:07:23 EST


This patch series addresses several unannotated data races between lockless
RCU-protected diagnostic reads in /proc/net/igmp (igmp_mc_seq_show())
and concurrent writes in serialized paths (RTNL and group spinlocks).

Following the precedent in commit 061c0aa740d5 ("ipv4: igmp: annotate
data-races around im->users"), we annotate these intentional data races
using READ_ONCE() and WRITE_ONCE() macros.

- Patch 1 annotates races around `in_dev->mc_count` (interface-level joins).
- Patch 2 annotates races around active timer-related state tracking fields
(`tm_running`, `reporter`, `expires`) on individual multicast groups.

Yuyang Huang (2):
ipv4: igmp: annotate data-races around in_dev->mc_count
ipv4: igmp: annotate data-races around timer-related fields

net/ipv4/igmp.c | 35 ++++++++++++++++++++---------------
1 file changed, 20 insertions(+), 15 deletions(-)

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2.54.0.823.g6e5bcc1fc9-goog