kernel/net, branch linux-rolling-lts

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

2026-03-19T15:08:50Z

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

2026-03-19T15:08:42Z

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

2026-03-19T15:08:40Z

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

2026-03-19T15:08:40Z

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

2026-03-19T15:08:37Z

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-ao: Fix MAC comparison to be constant-time

2026-03-19T15:08:36Z

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

libceph: admit message frames only in CEPH_CON_S_OPEN state

2026-03-19T15:08:30Z

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()

2026-03-19T15:08:30Z

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()

2026-03-19T15:08:30Z

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

libceph: reject preamble if control segment is empty

2026-03-19T15:08:30Z

commit c4c22b846eceff05b1129b8844a80310e55a7f87 upstream. While head_onwire_len() has a branch to handle ctrl_len == 0 case, prepare_read_control() always sets up a kvec for the CRC meaning that a non-empty control segment is effectively assumed. All frames that clients deal with meet that assumption, so let's make it official and treat the preamble with an empty control segment as malformed. Cc: stable@vger.kernel.org Signed-off-by: Ilya Dryomov Reviewed-by: Alex Markuze Signed-off-by: Greg Kroah-Hartman