This is a note to let you know that I've just added the patch titled
ila: serialize calls to nf_register_net_hooks()
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ila-serialize-calls-to-nf_register_net_hooks.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 6aad491964307de28af3662021bbac8b63ddda90
Author: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Mon Dec 30 16:28:49 2024 +0000
ila: serialize calls to nf_register_net_hooks()
[ Upstream commit 260466b576bca0081a7d4acecc8e93687aa22d0e ]
syzbot found a race in ila_add_mapping() [1]
commit 031ae72825ce ("ila: call nf_unregister_net_hooks() sooner")
attempted to fix a similar issue.
Looking at the syzbot repro, we have concurrent ILA_CMD_ADD commands.
Add a mutex to make sure at most one thread is calling nf_register_net_hooks().
[1]
BUG: KASAN: slab-use-after-free in rht_key_hashfn include/linux/rhashtable.h:159 [inline]
BUG: KASAN: slab-use-after-free in __rhashtable_lookup.constprop.0+0x426/0x550 include/linux/rhashtable.h:604
Read of size 4 at addr ffff888028f40008 by task dhcpcd/5501
CPU: 1 UID: 0 PID: 5501 Comm: dhcpcd Not tainted 6.13.0-rc4-syzkaller-00054-gd6ef8b40d075 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xc3/0x620 mm/kasan/report.c:489
kasan_report+0xd9/0x110 mm/kasan/report.c:602
rht_key_hashfn include/linux/rhashtable.h:159 [inline]
__rhashtable_lookup.constprop.0+0x426/0x550 include/linux/rhashtable.h:604
rhashtable_lookup include/linux/rhashtable.h:646 [inline]
rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline]
ila_lookup_wildcards net/ipv6/ila/ila_xlat.c:127 [inline]
ila_xlat_addr net/ipv6/ila/ila_xlat.c:652 [inline]
ila_nf_input+0x1ee/0x620 net/ipv6/ila/ila_xlat.c:185
nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
nf_hook_slow+0xbb/0x200 net/netfilter/core.c:626
nf_hook.constprop.0+0x42e/0x750 include/linux/netfilter.h:269
NF_HOOK include/linux/netfilter.h:312 [inline]
ipv6_rcv+0xa4/0x680 net/ipv6/ip6_input.c:309
__netif_receive_skb_one_core+0x12e/0x1e0 net/core/dev.c:5672
__netif_receive_skb+0x1d/0x160 net/core/dev.c:5785
process_backlog+0x443/0x15f0 net/core/dev.c:6117
__napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:6883
napi_poll net/core/dev.c:6952 [inline]
net_rx_action+0xa94/0x1010 net/core/dev.c:7074
handle_softirqs+0x213/0x8f0 kernel/softirq.c:561
__do_softirq kernel/softirq.c:595 [inline]
invoke_softirq kernel/softirq.c:435 [inline]
__irq_exit_rcu+0x109/0x170 kernel/softirq.c:662
irq_exit_rcu+0x9/0x30 kernel/softirq.c:678
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1049
Fixes: 7f00feaf1076 ("ila: Add generic ILA translation facility")
Reported-by: syzbot+47e761d22ecf745f72b9@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://lore.kernel.org/netdev/6772c9ae.050a0220.2f3838.04c7.GAE@xxxxxxxxxx/T/#u
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Florian Westphal <fw@xxxxxxxxx>
Cc: Tom Herbert <tom@xxxxxxxxxxxxxxx>
Link: https://patch.msgid.link/20241230162849.2795486-1-edumazet@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/ipv6/ila/ila_xlat.c b/net/ipv6/ila/ila_xlat.c
index 2e7a36a1ea0a..8483116dfa23 100644
--- a/net/ipv6/ila/ila_xlat.c
+++ b/net/ipv6/ila/ila_xlat.c
@@ -201,6 +201,8 @@ static const struct nf_hook_ops ila_nf_hook_ops[] = {
},
};
+static DEFINE_MUTEX(ila_mutex);
+
static int ila_add_mapping(struct net *net, struct ila_xlat_params *xp)
{
struct ila_net *ilan = net_generic(net, ila_net_id);
@@ -208,16 +210,20 @@ static int ila_add_mapping(struct net *net, struct ila_xlat_params *xp)
spinlock_t *lock = ila_get_lock(ilan, xp->ip.locator_match);
int err = 0, order;
- if (!ilan->xlat.hooks_registered) {
+ if (!READ_ONCE(ilan->xlat.hooks_registered)) {
/* We defer registering net hooks in the namespace until the
* first mapping is added.
*/
- err = nf_register_net_hooks(net, ila_nf_hook_ops,
- ARRAY_SIZE(ila_nf_hook_ops));
+ mutex_lock(&ila_mutex);
+ if (!ilan->xlat.hooks_registered) {
+ err = nf_register_net_hooks(net, ila_nf_hook_ops,
+ ARRAY_SIZE(ila_nf_hook_ops));
+ if (!err)
+ WRITE_ONCE(ilan->xlat.hooks_registered, true);
+ }
+ mutex_unlock(&ila_mutex);
if (err)
return err;
-
- ilan->xlat.hooks_registered = true;
}
ila = kzalloc(sizeof(*ila), GFP_KERNEL);
