diff options
| author | Yuyang Huang <sigefriedhyy@gmail.com> | 2026-06-09 17:11:13 +0900 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-06-12 17:12:08 -0700 |
| commit | 1ea2f885a76bc261c5b81c4a01477eacf8025e30 (patch) | |
| tree | 4d5c217702a5061ce0acf3e290fd6b7da5fef680 | |
| parent | d0dc208808a28f7380fdc40e587b054f6cc81bc1 (diff) | |
ipv6: mcast: annotate igmp6 timer expiry race
/proc/net/igmp6 walks IPv6 multicast memberships under RCU and reads
mca_work.timer.expires to print the remaining multicast timer. The
delayed-work timer can be updated concurrently.
Annotate the intentional lockless procfs snapshot with READ_ONCE().
Signed-off-by: Yuyang Huang <sigefriedhyy@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260609081113.7613-3-sigefriedhyy@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/ipv6/mcast.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c index bd3972730aa0..04b811b3be97 100644 --- a/net/ipv6/mcast.c +++ b/net/ipv6/mcast.c @@ -2984,6 +2984,7 @@ static int igmp6_mc_seq_show(struct seq_file *seq, void *v) struct ifmcaddr6 *im = (struct ifmcaddr6 *)v; struct igmp6_mc_iter_state *state = igmp6_mc_seq_private(seq); unsigned int mca_flags = READ_ONCE(im->mca_flags); + unsigned long expires = READ_ONCE(im->mca_work.timer.expires); seq_printf(seq, "%-4d %-15s %pi6 %5d %08X %ld\n", @@ -2991,7 +2992,7 @@ static int igmp6_mc_seq_show(struct seq_file *seq, void *v) &im->mca_addr, READ_ONCE(im->mca_users), mca_flags, (mca_flags & MAF_TIMER_RUNNING) ? - jiffies_to_clock_t(im->mca_work.timer.expires - jiffies) : 0); + jiffies_to_clock_t(expires - jiffies) : 0); return 0; } |