* FAILED: patch "[PATCH] ipv6: ioam: add NULL check for idev in ipv6_hop_ioam()" failed to apply to 6.6-stable tree
@ 2026-05-28 9:58 gregkh
2026-05-29 23:53 ` [PATCH 6.6.y 1/2] ipv6/addrconf: annotate data-races around devconf fields (II) Sasha Levin
0 siblings, 1 reply; 3+ messages in thread
From: gregkh @ 2026-05-28 9:58 UTC (permalink / raw)
To: justin.iurman, idosch, kuba; +Cc: stable
The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x d4ea0dfd75011b78cebf3808f98ac4c4f51a6fb9
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026052812-uncoated-spry-43e1@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From d4ea0dfd75011b78cebf3808f98ac4c4f51a6fb9 Mon Sep 17 00:00:00 2001
From: Justin Iurman <justin.iurman@gmail.com>
Date: Sun, 17 May 2026 20:30:59 +0200
Subject: [PATCH] ipv6: ioam: add NULL check for idev in ipv6_hop_ioam()
Reported by Sashiko:
The function ipv6_hop_ioam() accesses
__in6_dev_get(skb->dev)->cnf.ioam6_enabled without validating the returned
idev pointer. Because addrconf_ifdown() can concurrently clear dev->ip6_ptr
via RCU, __in6_dev_get() can return NULL during interface teardown, which
could cause a NULL pointer dereference when processing an IOAM Hop-by-Hop
option.
Let's add a check and use SKB_DROP_REASON_IPV6DISABLED accordingly.
Fixes: 9ee11f0fff20 ("ipv6: ioam: Data plane support for Pre-allocated Trace")
Cc: stable@vger.kernel.org
Signed-off-by: Justin Iurman <justin.iurman@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260517183059.29140-1-justin.iurman@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index 03cbce842c1a..47c5502a34a2 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -910,16 +910,27 @@ static bool ipv6_hop_ra(struct sk_buff *skb, int optoff)
static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff)
{
+ enum skb_drop_reason drop_reason;
struct ioam6_trace_hdr *trace;
struct ioam6_namespace *ns;
+ struct inet6_dev *idev;
struct ioam6_hdr *hdr;
+ drop_reason = SKB_DROP_REASON_IP_INHDR;
+
/* Bad alignment (must be 4n-aligned) */
if (optoff & 3)
goto drop;
+ /* Does the device still have IPv6 configuration? */
+ idev = __in6_dev_get(skb->dev);
+ if (!idev) {
+ drop_reason = SKB_DROP_REASON_IPV6DISABLED;
+ goto drop;
+ }
+
/* Ignore if IOAM is not enabled on ingress */
- if (!READ_ONCE(__in6_dev_get(skb->dev)->cnf.ioam6_enabled))
+ if (!READ_ONCE(idev->cnf.ioam6_enabled))
goto ignore;
/* Truncated Option header */
@@ -972,7 +983,7 @@ static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff)
return true;
drop:
- kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR);
+ kfree_skb_reason(skb, drop_reason);
return false;
}
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH 6.6.y 1/2] ipv6/addrconf: annotate data-races around devconf fields (II)
2026-05-28 9:58 FAILED: patch "[PATCH] ipv6: ioam: add NULL check for idev in ipv6_hop_ioam()" failed to apply to 6.6-stable tree gregkh
@ 2026-05-29 23:53 ` Sasha Levin
2026-05-29 23:53 ` [PATCH 6.6.y 2/2] ipv6: ioam: add NULL check for idev in ipv6_hop_ioam() Sasha Levin
0 siblings, 1 reply; 3+ messages in thread
From: Sasha Levin @ 2026-05-29 23:53 UTC (permalink / raw)
To: stable; +Cc: Eric Dumazet, Jiri Pirko, David S. Miller, Sasha Levin
From: Eric Dumazet <edumazet@google.com>
[ Upstream commit 2f0ff05a44302c91af54a5f9efe1b65b7681540e ]
Final (?) round of this series.
Annotate lockless reads on following devconf fields,
because they be changed concurrently from /proc/net/ipv6/conf.
- accept_dad
- optimistic_dad
- use_optimistic
- use_oif_addrs_only
- ra_honor_pio_life
- keep_addr_on_down
- ndisc_notify
- ndisc_evict_nocarrier
- suppress_frag_ndisc
- addr_gen_mode
- seg6_enabled
- ioam6_enabled
- ioam6_id
- ioam6_id_wide
- drop_unicast_in_l2_multicast
- mldv[12]_unsolicited_report_interval
- force_mld_version
- force_tllao
- accept_untracked_na
- drop_unsolicited_na
- accept_source_route
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: d4ea0dfd7501 ("ipv6: ioam: add NULL check for idev in ipv6_hop_ioam()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv6/addrconf.c | 47 +++++++++++++++++++++++---------------------
net/ipv6/exthdrs.c | 16 ++++++++-------
net/ipv6/ioam6.c | 8 ++++----
net/ipv6/ip6_input.c | 2 +-
net/ipv6/mcast.c | 14 ++++++-------
net/ipv6/ndisc.c | 18 ++++++++---------
net/ipv6/seg6_hmac.c | 8 +++++---
7 files changed, 60 insertions(+), 53 deletions(-)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 32fa6236dacdd..c880590090b34 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1518,15 +1518,17 @@ static inline int ipv6_saddr_preferred(int type)
return 0;
}
-static bool ipv6_use_optimistic_addr(struct net *net,
- struct inet6_dev *idev)
+static bool ipv6_use_optimistic_addr(const struct net *net,
+ const struct inet6_dev *idev)
{
#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
if (!idev)
return false;
- if (!net->ipv6.devconf_all->optimistic_dad && !idev->cnf.optimistic_dad)
+ if (!READ_ONCE(net->ipv6.devconf_all->optimistic_dad) &&
+ !READ_ONCE(idev->cnf.optimistic_dad))
return false;
- if (!net->ipv6.devconf_all->use_optimistic && !idev->cnf.use_optimistic)
+ if (!READ_ONCE(net->ipv6.devconf_all->use_optimistic) &&
+ !READ_ONCE(idev->cnf.use_optimistic))
return false;
return true;
@@ -1535,13 +1537,14 @@ static bool ipv6_use_optimistic_addr(struct net *net,
#endif
}
-static bool ipv6_allow_optimistic_dad(struct net *net,
- struct inet6_dev *idev)
+static bool ipv6_allow_optimistic_dad(const struct net *net,
+ const struct inet6_dev *idev)
{
#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
if (!idev)
return false;
- if (!net->ipv6.devconf_all->optimistic_dad && !idev->cnf.optimistic_dad)
+ if (!READ_ONCE(net->ipv6.devconf_all->optimistic_dad) &&
+ !READ_ONCE(idev->cnf.optimistic_dad))
return false;
return true;
@@ -1823,7 +1826,7 @@ int ipv6_dev_get_saddr(struct net *net, const struct net_device *dst_dev,
idev = __in6_dev_get(dst_dev);
if ((dst_type & IPV6_ADDR_MULTICAST) ||
dst.scope <= IPV6_ADDR_SCOPE_LINKLOCAL ||
- (idev && idev->cnf.use_oif_addrs_only)) {
+ (idev && READ_ONCE(idev->cnf.use_oif_addrs_only))) {
use_oif_addr = true;
}
}
@@ -2662,8 +2665,8 @@ int addrconf_prefix_rcv_add_addr(struct net *net, struct net_device *dev,
};
#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
- if ((net->ipv6.devconf_all->optimistic_dad ||
- in6_dev->cnf.optimistic_dad) &&
+ if ((READ_ONCE(net->ipv6.devconf_all->optimistic_dad) ||
+ READ_ONCE(in6_dev->cnf.optimistic_dad)) &&
!net->ipv6.devconf_all->forwarding && sllao)
cfg.ifa_flags |= IFA_F_OPTIMISTIC;
#endif
@@ -3293,8 +3296,8 @@ void addrconf_add_linklocal(struct inet6_dev *idev,
struct inet6_ifaddr *ifp;
#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
- if ((dev_net(idev->dev)->ipv6.devconf_all->optimistic_dad ||
- idev->cnf.optimistic_dad) &&
+ if ((READ_ONCE(dev_net(idev->dev)->ipv6.devconf_all->optimistic_dad) ||
+ READ_ONCE(idev->cnf.optimistic_dad)) &&
!dev_net(idev->dev)->ipv6.devconf_all->forwarding)
cfg.ifa_flags |= IFA_F_OPTIMISTIC;
#endif
@@ -3866,10 +3869,10 @@ static int addrconf_ifdown(struct net_device *dev, bool unregister)
*/
if (!unregister && !idev->cnf.disable_ipv6) {
/* aggregate the system setting and interface setting */
- int _keep_addr = net->ipv6.devconf_all->keep_addr_on_down;
+ int _keep_addr = READ_ONCE(net->ipv6.devconf_all->keep_addr_on_down);
if (!_keep_addr)
- _keep_addr = idev->cnf.keep_addr_on_down;
+ _keep_addr = READ_ONCE(idev->cnf.keep_addr_on_down);
keep_addr = (_keep_addr > 0);
}
@@ -4090,8 +4093,8 @@ static void addrconf_dad_begin(struct inet6_ifaddr *ifp)
net = dev_net(dev);
if (dev->flags&(IFF_NOARP|IFF_LOOPBACK) ||
- (net->ipv6.devconf_all->accept_dad < 1 &&
- idev->cnf.accept_dad < 1) ||
+ (READ_ONCE(net->ipv6.devconf_all->accept_dad) < 1 &&
+ READ_ONCE(idev->cnf.accept_dad) < 1) ||
!(ifp->flags&IFA_F_TENTATIVE) ||
ifp->flags & IFA_F_NODAD) {
bool send_na = false;
@@ -4183,8 +4186,8 @@ static void addrconf_dad_work(struct work_struct *w)
action = DAD_ABORT;
ifp->state = INET6_IFADDR_STATE_POSTDAD;
- if ((dev_net(idev->dev)->ipv6.devconf_all->accept_dad > 1 ||
- idev->cnf.accept_dad > 1) &&
+ if ((READ_ONCE(dev_net(idev->dev)->ipv6.devconf_all->accept_dad) > 1 ||
+ READ_ONCE(idev->cnf.accept_dad) > 1) &&
!idev->cnf.disable_ipv6 &&
!(ifp->flags & IFA_F_STABLE_PRIVACY)) {
struct in6_addr addr;
@@ -4323,8 +4326,8 @@ static void addrconf_dad_completed(struct inet6_ifaddr *ifp, bool bump_id,
/* send unsolicited NA if enabled */
if (send_na &&
- (ifp->idev->cnf.ndisc_notify ||
- dev_net(dev)->ipv6.devconf_all->ndisc_notify)) {
+ (READ_ONCE(ifp->idev->cnf.ndisc_notify) ||
+ READ_ONCE(dev_net(dev)->ipv6.devconf_all->ndisc_notify))) {
ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifp->addr,
/*router=*/ !!ifp->idev->cnf.forwarding,
/*solicited=*/ false, /*override=*/ true,
@@ -6520,7 +6523,7 @@ static int addrconf_sysctl_addr_gen_mode(struct ctl_table *ctl, int write,
} else if (&net->ipv6.devconf_all->addr_gen_mode == ctl->data) {
struct net_device *dev;
- net->ipv6.devconf_dflt->addr_gen_mode = new_val;
+ WRITE_ONCE(net->ipv6.devconf_dflt->addr_gen_mode, new_val);
for_each_netdev(net, dev) {
idev = __in6_dev_get(dev);
if (idev &&
@@ -6531,7 +6534,7 @@ static int addrconf_sysctl_addr_gen_mode(struct ctl_table *ctl, int write,
}
}
- *((u32 *)ctl->data) = new_val;
+ WRITE_ONCE(*((u32 *)ctl->data), new_val);
}
out:
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index 54e71623aac9c..404555311bc74 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -383,9 +383,8 @@ static int ipv6_srh_rcv(struct sk_buff *skb)
return -1;
}
- accept_seg6 = net->ipv6.devconf_all->seg6_enabled;
- if (accept_seg6 > idev->cnf.seg6_enabled)
- accept_seg6 = idev->cnf.seg6_enabled;
+ accept_seg6 = min(READ_ONCE(net->ipv6.devconf_all->seg6_enabled),
+ READ_ONCE(idev->cnf.seg6_enabled));
if (!accept_seg6) {
kfree_skb(skb);
@@ -662,10 +661,13 @@ static int ipv6_rthdr_rcv(struct sk_buff *skb)
struct ipv6_rt_hdr *hdr;
struct rt0_hdr *rthdr;
struct net *net = dev_net(skb->dev);
- int accept_source_route = net->ipv6.devconf_all->accept_source_route;
+ int accept_source_route;
- if (idev && accept_source_route > idev->cnf.accept_source_route)
- accept_source_route = idev->cnf.accept_source_route;
+ accept_source_route = READ_ONCE(net->ipv6.devconf_all->accept_source_route);
+
+ if (idev)
+ accept_source_route = min(accept_source_route,
+ READ_ONCE(idev->cnf.accept_source_route));
if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
!pskb_may_pull(skb, (skb_transport_offset(skb) +
@@ -926,7 +928,7 @@ static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff)
goto drop;
/* Ignore if IOAM is not enabled on ingress */
- if (!__in6_dev_get(skb->dev)->cnf.ioam6_enabled)
+ if (!READ_ONCE(__in6_dev_get(skb->dev)->cnf.ioam6_enabled))
goto ignore;
/* Truncated Option header */
diff --git a/net/ipv6/ioam6.c b/net/ipv6/ioam6.c
index a1953cf6131be..fee1e23c3ae19 100644
--- a/net/ipv6/ioam6.c
+++ b/net/ipv6/ioam6.c
@@ -677,7 +677,7 @@ static void __ioam6_fill_trace_data(struct sk_buff *skb,
if (!skb->dev)
raw16 = IOAM6_U16_UNAVAILABLE;
else
- raw16 = (__force u16)__in6_dev_get(skb->dev)->cnf.ioam6_id;
+ raw16 = (__force u16)READ_ONCE(__in6_dev_get(skb->dev)->cnf.ioam6_id);
*(__be16 *)data = cpu_to_be16(raw16);
data += sizeof(__be16);
@@ -685,7 +685,7 @@ static void __ioam6_fill_trace_data(struct sk_buff *skb,
if (skb_dst(skb)->dev->flags & IFF_LOOPBACK)
raw16 = IOAM6_U16_UNAVAILABLE;
else
- raw16 = (__force u16)__in6_dev_get(skb_dst(skb)->dev)->cnf.ioam6_id;
+ raw16 = (__force u16)READ_ONCE(__in6_dev_get(skb_dst(skb)->dev)->cnf.ioam6_id);
*(__be16 *)data = cpu_to_be16(raw16);
data += sizeof(__be16);
@@ -772,7 +772,7 @@ static void __ioam6_fill_trace_data(struct sk_buff *skb,
if (!skb->dev)
raw32 = IOAM6_U32_UNAVAILABLE;
else
- raw32 = __in6_dev_get(skb->dev)->cnf.ioam6_id_wide;
+ raw32 = READ_ONCE(__in6_dev_get(skb->dev)->cnf.ioam6_id_wide);
*(__be32 *)data = cpu_to_be32(raw32);
data += sizeof(__be32);
@@ -780,7 +780,7 @@ static void __ioam6_fill_trace_data(struct sk_buff *skb,
if (skb_dst(skb)->dev->flags & IFF_LOOPBACK)
raw32 = IOAM6_U32_UNAVAILABLE;
else
- raw32 = __in6_dev_get(skb_dst(skb)->dev)->cnf.ioam6_id_wide;
+ raw32 = READ_ONCE(__in6_dev_get(skb_dst(skb)->dev)->cnf.ioam6_id_wide);
*(__be32 *)data = cpu_to_be32(raw32);
data += sizeof(__be32);
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 1ba97933c74fb..133610a49da6b 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -236,7 +236,7 @@ static struct sk_buff *ip6_rcv_core(struct sk_buff *skb, struct net_device *dev,
if (!ipv6_addr_is_multicast(&hdr->daddr) &&
(skb->pkt_type == PACKET_BROADCAST ||
skb->pkt_type == PACKET_MULTICAST) &&
- idev->cnf.drop_unicast_in_l2_multicast) {
+ READ_ONCE(idev->cnf.drop_unicast_in_l2_multicast)) {
SKB_DR_SET(reason, UNICAST_IN_L2_MULTICAST);
goto err;
}
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 160b452f75e7d..a52c92b1f321e 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -159,9 +159,9 @@ static int unsolicited_report_interval(struct inet6_dev *idev)
int iv;
if (mld_in_v1_mode(idev))
- iv = idev->cnf.mldv1_unsolicited_report_interval;
+ iv = READ_ONCE(idev->cnf.mldv1_unsolicited_report_interval);
else
- iv = idev->cnf.mldv2_unsolicited_report_interval;
+ iv = READ_ONCE(idev->cnf.mldv2_unsolicited_report_interval);
return iv > 0 ? iv : 1;
}
@@ -1201,15 +1201,15 @@ static bool mld_marksources(struct ifmcaddr6 *pmc, int nsrcs,
static int mld_force_mld_version(const struct inet6_dev *idev)
{
+ const struct net *net = dev_net(idev->dev);
+ int all_force;
+
+ all_force = READ_ONCE(net->ipv6.devconf_all->force_mld_version);
/* Normally, both are 0 here. If enforcement to a particular is
* being used, individual device enforcement will have a lower
* precedence over 'all' device (.../conf/all/force_mld_version).
*/
-
- if (dev_net(idev->dev)->ipv6.devconf_all->force_mld_version != 0)
- return dev_net(idev->dev)->ipv6.devconf_all->force_mld_version;
- else
- return idev->cnf.force_mld_version;
+ return all_force ?: READ_ONCE(idev->cnf.force_mld_version);
}
static bool mld_in_v2_mode_only(const struct inet6_dev *idev)
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 652263e2f2d02..ee34831f5621a 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -451,7 +451,7 @@ static void ip6_nd_hdr(struct sk_buff *skb,
rcu_read_lock();
idev = __in6_dev_get(skb->dev);
- tclass = idev ? idev->cnf.ndisc_tclass : 0;
+ tclass = idev ? READ_ONCE(idev->cnf.ndisc_tclass) : 0;
rcu_read_unlock();
skb_push(skb, sizeof(*hdr));
@@ -539,7 +539,7 @@ void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
src_addr = solicited_addr;
if (ifp->flags & IFA_F_OPTIMISTIC)
override = false;
- inc_opt |= ifp->idev->cnf.force_tllao;
+ inc_opt |= READ_ONCE(ifp->idev->cnf.force_tllao);
in6_ifa_put(ifp);
} else {
if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
@@ -977,7 +977,7 @@ static int accept_untracked_na(struct net_device *dev, struct in6_addr *saddr)
{
struct inet6_dev *idev = __in6_dev_get(dev);
- switch (idev->cnf.accept_untracked_na) {
+ switch (READ_ONCE(idev->cnf.accept_untracked_na)) {
case 0: /* Don't accept untracked na (absent in neighbor cache) */
return 0;
case 1: /* Create new entries from na if currently untracked */
@@ -1028,7 +1028,7 @@ static enum skb_drop_reason ndisc_recv_na(struct sk_buff *skb)
* drop_unsolicited_na takes precedence over accept_untracked_na
*/
if (!msg->icmph.icmp6_solicited && idev &&
- idev->cnf.drop_unsolicited_na)
+ READ_ONCE(idev->cnf.drop_unsolicited_na))
return reason;
if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts))
@@ -1821,7 +1821,7 @@ static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
if (!idev)
return true;
if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
- idev->cnf.suppress_frag_ndisc) {
+ READ_ONCE(idev->cnf.suppress_frag_ndisc)) {
net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
return true;
}
@@ -1898,8 +1898,8 @@ static int ndisc_netdev_event(struct notifier_block *this, unsigned long event,
idev = in6_dev_get(dev);
if (!idev)
break;
- if (idev->cnf.ndisc_notify ||
- net->ipv6.devconf_all->ndisc_notify)
+ if (READ_ONCE(idev->cnf.ndisc_notify) ||
+ READ_ONCE(net->ipv6.devconf_all->ndisc_notify))
ndisc_send_unsol_na(dev);
in6_dev_put(idev);
break;
@@ -1908,8 +1908,8 @@ static int ndisc_netdev_event(struct notifier_block *this, unsigned long event,
if (!idev)
evict_nocarrier = true;
else {
- evict_nocarrier = idev->cnf.ndisc_evict_nocarrier &&
- net->ipv6.devconf_all->ndisc_evict_nocarrier;
+ evict_nocarrier = READ_ONCE(idev->cnf.ndisc_evict_nocarrier) &&
+ READ_ONCE(net->ipv6.devconf_all->ndisc_evict_nocarrier);
in6_dev_put(idev);
}
diff --git a/net/ipv6/seg6_hmac.c b/net/ipv6/seg6_hmac.c
index bf97bf5ac1387..214d137d545e7 100644
--- a/net/ipv6/seg6_hmac.c
+++ b/net/ipv6/seg6_hmac.c
@@ -242,6 +242,7 @@ bool seg6_hmac_validate_skb(struct sk_buff *skb)
struct sr6_tlv_hmac *tlv;
struct ipv6_sr_hdr *srh;
struct inet6_dev *idev;
+ int require_hmac;
idev = __in6_dev_get(skb->dev);
if (!idev)
@@ -251,16 +252,17 @@ bool seg6_hmac_validate_skb(struct sk_buff *skb)
tlv = seg6_get_tlv_hmac(srh);
+ require_hmac = READ_ONCE(idev->cnf.seg6_require_hmac);
/* mandatory check but no tlv */
- if (idev->cnf.seg6_require_hmac > 0 && !tlv)
+ if (require_hmac > 0 && !tlv)
return false;
/* no check */
- if (idev->cnf.seg6_require_hmac < 0)
+ if (require_hmac < 0)
return true;
/* check only if present */
- if (idev->cnf.seg6_require_hmac == 0 && !tlv)
+ if (require_hmac == 0 && !tlv)
return true;
/* now, seg6_require_hmac >= 0 && tlv */
--
2.53.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH 6.6.y 2/2] ipv6: ioam: add NULL check for idev in ipv6_hop_ioam()
2026-05-29 23:53 ` [PATCH 6.6.y 1/2] ipv6/addrconf: annotate data-races around devconf fields (II) Sasha Levin
@ 2026-05-29 23:53 ` Sasha Levin
0 siblings, 0 replies; 3+ messages in thread
From: Sasha Levin @ 2026-05-29 23:53 UTC (permalink / raw)
To: stable; +Cc: Justin Iurman, Ido Schimmel, Jakub Kicinski, Sasha Levin
From: Justin Iurman <justin.iurman@gmail.com>
[ Upstream commit d4ea0dfd75011b78cebf3808f98ac4c4f51a6fb9 ]
Reported by Sashiko:
The function ipv6_hop_ioam() accesses
__in6_dev_get(skb->dev)->cnf.ioam6_enabled without validating the returned
idev pointer. Because addrconf_ifdown() can concurrently clear dev->ip6_ptr
via RCU, __in6_dev_get() can return NULL during interface teardown, which
could cause a NULL pointer dereference when processing an IOAM Hop-by-Hop
option.
Let's add a check and use SKB_DROP_REASON_IPV6DISABLED accordingly.
Fixes: 9ee11f0fff20 ("ipv6: ioam: Data plane support for Pre-allocated Trace")
Cc: stable@vger.kernel.org
Signed-off-by: Justin Iurman <justin.iurman@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260517183059.29140-1-justin.iurman@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv6/exthdrs.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index 404555311bc74..f6f6830cc466e 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -919,16 +919,27 @@ static bool ipv6_hop_ra(struct sk_buff *skb, int optoff)
static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff)
{
+ enum skb_drop_reason drop_reason;
struct ioam6_trace_hdr *trace;
struct ioam6_namespace *ns;
+ struct inet6_dev *idev;
struct ioam6_hdr *hdr;
+ drop_reason = SKB_DROP_REASON_IP_INHDR;
+
/* Bad alignment (must be 4n-aligned) */
if (optoff & 3)
goto drop;
+ /* Does the device still have IPv6 configuration? */
+ idev = __in6_dev_get(skb->dev);
+ if (!idev) {
+ drop_reason = SKB_DROP_REASON_IPV6DISABLED;
+ goto drop;
+ }
+
/* Ignore if IOAM is not enabled on ingress */
- if (!READ_ONCE(__in6_dev_get(skb->dev)->cnf.ioam6_enabled))
+ if (!READ_ONCE(idev->cnf.ioam6_enabled))
goto ignore;
/* Truncated Option header */
@@ -978,7 +989,7 @@ static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff)
return true;
drop:
- kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR);
+ kfree_skb_reason(skb, drop_reason);
return false;
}
--
2.53.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
end of thread, other threads:[~2026-05-29 23:53 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-05-28 9:58 FAILED: patch "[PATCH] ipv6: ioam: add NULL check for idev in ipv6_hop_ioam()" failed to apply to 6.6-stable tree gregkh
2026-05-29 23:53 ` [PATCH 6.6.y 1/2] ipv6/addrconf: annotate data-races around devconf fields (II) Sasha Levin
2026-05-29 23:53 ` [PATCH 6.6.y 2/2] ipv6: ioam: add NULL check for idev in ipv6_hop_ioam() Sasha Levin
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