kernel/net, branch linux-rolling-stable

net-shapers: don't free reply skb after genlmsg_reply()

2026-03-19T15:15:25Z

commit 57885276cc16a2e2b76282c808a4e84cbecb3aae upstream. genlmsg_reply() hands the reply skb to netlink, and netlink_unicast() consumes it on all return paths, whether the skb is queued successfully or freed on an error path. net_shaper_nl_get_doit() and net_shaper_nl_cap_get_doit() currently jump to free_msg after genlmsg_reply() fails and call nlmsg_free(msg), which can hit the same skb twice. Return the genlmsg_reply() error directly and keep free_msg only for pre-reply failures. Fixes: 4b623f9f0f59 ("net-shapers: implement NL get operation") Fixes: 553ea9f1efd6 ("net: shaper: implement introspection support") Cc: stable@vger.kernel.org Signed-off-by: Paul Moses Link: https://patch.msgid.link/20260309173450.538026-2-p@1g4.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net: ncsi: fix skb leak in error paths

2026-03-19T15:15:22Z

commit 5c3398a54266541610c8d0a7082e654e9ff3e259 upstream. Early return paths in NCSI RX and AEN handlers fail to release the received skb, resulting in a memory leak. Specifically, ncsi_aen_handler() returns on invalid AEN packets without consuming the skb. Similarly, ncsi_rcv_rsp() exits early when failing to resolve the NCSI device, response handler, or request, leaving the skb unfreed. CC: stable@vger.kernel.org Fixes: 7a82ecf4cfb8 ("net/ncsi: NCSI AEN packet handler") Fixes: 138635cc27c9 ("net/ncsi: NCSI response packet handler") Signed-off-by: Jian Zhang Link: https://patch.msgid.link/20260305060656.3357250-1-zhangjian.3032@bytedance.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net: nexthop: fix percpu use-after-free in remove_nh_grp_entry

2026-03-19T15:15:22Z

commit b2662e7593e94ae09b1cf7ee5f09160a3612bcb2 upstream. When removing a nexthop from a group, remove_nh_grp_entry() publishes the new group via rcu_assign_pointer() then immediately frees the removed entry's percpu stats with free_percpu(). However, the synchronize_net() grace period in the caller remove_nexthop_from_groups() runs after the free. RCU readers that entered before the publish still see the old group and can dereference the freed stats via nh_grp_entry_stats_inc() -> get_cpu_ptr(nhge->stats), causing a use-after-free on percpu memory. Fix by deferring the free_percpu() until after synchronize_net() in the caller. Removed entries are chained via nh_list onto a local deferred free list. After the grace period completes and all RCU readers have finished, the percpu stats are safely freed. Fixes: f4676ea74b85 ("net: nexthop: Add nexthop group entry stats") Cc: stable@vger.kernel.org Signed-off-by: Mehul Rao Reviewed-by: Eric Dumazet Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/20260306233821.196789-1-mehulrao@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

batman-adv: Avoid double-rtnl_lock ELP metric worker

2026-03-19T15:15:19Z

commit cfc83a3c71517b59c1047db57da31e26a9dc2f33 upstream. batadv_v_elp_get_throughput() might be called when the RTNL lock is already held. This could be problematic when the work queue item is cancelled via cancel_delayed_work_sync() in batadv_v_elp_iface_disable(). In this case, an rtnl_lock() would cause a deadlock. To avoid this, rtnl_trylock() was used in this function to skip the retrieval of the ethtool information in case the RTNL lock was already held. But for cfg80211 interfaces, batadv_get_real_netdev() was called - which also uses rtnl_lock(). The approach for __ethtool_get_link_ksettings() must also be used instead and the lockless version __batadv_get_real_netdev() has to be called. Cc: stable@vger.kernel.org Fixes: 8c8ecc98f5c6 ("batman-adv: Drop unmanaged ELP metric worker") Reported-by: Christian Schmidbauer Signed-off-by: Sven Eckelmann Tested-by: Sören Skaarup Signed-off-by: Simon Wunderlich Signed-off-by: Greg Kroah-Hartman

net/tcp-md5: Fix MAC comparison to be constant-time

2026-03-19T15:15:18Z

commit 46d0d6f50dab706637f4c18a470aac20a21900d3 upstream. To prevent timing attacks, MACs need to be compared in constant time. Use the appropriate helper function for this. Fixes: cfb6eeb4c860 ("[TCP]: MD5 Signature Option (RFC2385) support.") Fixes: 658ddaaf6694 ("tcp: md5: RST: getting md5 key from listener") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Link: https://patch.msgid.link/20260302203409.13388-1-ebiggers@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net/tcp-ao: Fix MAC comparison to be constant-time

2026-03-19T15:15:18Z

commit 67edfec516d30d3e62925c397be4a1e5185802fc upstream. To prevent timing attacks, MACs need to be compared in constant time. Use the appropriate helper function for this. Fixes: 0a3a809089eb ("net/tcp: Verify inbound TCP-AO signed segments") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com> Link: https://patch.msgid.link/20260302203600.13561-1-ebiggers@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net: Fix rcu_tasks stall in threaded busypoll

2026-03-19T15:15:18Z

commit 1a86a1f7d88996085934139fa4c063b6299a2dd3 upstream. I was debugging a NIC driver when I noticed that when I enable threaded busypoll, bpftrace hangs when starting up. dmesg showed: rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 10658 jiffies old. rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 40793 jiffies old. rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 131273 jiffies old. rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 402058 jiffies old. INFO: rcu_tasks detected stalls on tasks: 00000000769f52cd: .N nvcsw: 2/2 holdout: 1 idle_cpu: -1/64 task:napi/eth2-8265 state:R running task stack:0 pid:48300 tgid:48300 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: ? napi_threaded_poll_loop+0x27c/0x2c0 ? __pfx_napi_threaded_poll+0x10/0x10 ? napi_threaded_poll+0x26/0x80 ? kthread+0xfa/0x240 ? __pfx_kthread+0x10/0x10 ? ret_from_fork+0x31/0x50 ? __pfx_kthread+0x10/0x10 ? ret_from_fork_asm+0x1a/0x30 The cause is that in threaded busypoll, the main loop is in napi_threaded_poll rather than napi_threaded_poll_loop, where the latter rarely iterates more than once within its loop. For rcu_softirq_qs_periodic inside napi_threaded_poll_loop to report its qs state, the last_qs must be 100ms behind, and this can't happen because napi_threaded_poll_loop rarely iterates in threaded busypoll, and each time napi_threaded_poll_loop is called last_qs is reset to latest jiffies. This patch changes so that in threaded busypoll, last_qs is saved in the outer napi_threaded_poll, and whether busy_poll_last_qs is NULL indicates whether napi_threaded_poll_loop is called for busypoll. This way last_qs would not reset to latest jiffies on each invocation of napi_threaded_poll_loop. Fixes: c18d4b190a46 ("net: Extend NAPI threaded polling to allow kthread based busy polling") Cc: stable@vger.kernel.org Signed-off-by: YiFei Zhu Reviewed-by: Samiullah Khawaja Link: https://patch.msgid.link/20260227221937.1060857-1-zhuyifei@google.com Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman

libceph: admit message frames only in CEPH_CON_S_OPEN state

2026-03-19T15:15:11Z

commit a5a373705081d7cc6363e16990e2361b0b362314 upstream. Similar checks are performed for all control frames, but an early check for message frames was missing. process_message() is already set up to terminate the loop in case the state changes while con->ops->dispatch() handler is being executed. Cc: stable@vger.kernel.org Signed-off-by: Ilya Dryomov Reviewed-by: Alex Markuze Reviewed-by: Viacheslav Dubeyko Signed-off-by: Greg Kroah-Hartman

libceph: Use u32 for non-negative values in ceph_monmap_decode()

2026-03-19T15:15:11Z

commit 770444611f047dbfd4517ec0bc1b179d40c2f346 upstream. This patch fixes unnecessary implicit conversions that change signedness of blob_len and num_mon in ceph_monmap_decode(). Currently blob_len and num_mon are (signed) int variables. They are used to hold values that are always non-negative and get assigned in ceph_decode_32_safe(), which is meant to assign u32 values. Both variables are subsequently used as unsigned values, and the value of num_mon is further assigned to monmap->num_mon, which is of type u32. Therefore, both variables should be of type u32. This is especially relevant for num_mon. If the value read from the incoming message is very large, it is interpreted as a negative value, and the check for num_mon > CEPH_MAX_MON does not catch it. This leads to the attempt to allocate a very large chunk of memory for monmap, which will most likely fail. In this case, an unnecessary attempt to allocate memory is performed, and -ENOMEM is returned instead of -EINVAL. Cc: stable@vger.kernel.org Signed-off-by: Raphael Zimmer Reviewed-by: Viacheslav Dubeyko Reviewed-by: Ilya Dryomov Signed-off-by: Ilya Dryomov Signed-off-by: Greg Kroah-Hartman

libceph: prevent potential out-of-bounds reads in process_message_header()

2026-03-19T15:15:11Z

commit 69fb5d91bba44ecf7eb80530b85fa4fb028921d5 upstream. If the message frame is (maliciously) corrupted in a way that the length of the control segment ends up being less than the size of the message header or a different frame is made to look like a message frame, out-of-bounds reads may ensue in process_message_header(). Perform an explicit bounds check before decoding the message header. Cc: stable@vger.kernel.org Reported-by: Raphael Zimmer Signed-off-by: Ilya Dryomov Reviewed-by: Alex Markuze Reviewed-by: Viacheslav Dubeyko Signed-off-by: Greg Kroah-Hartman