kernel/linux.git/include/linux/netdevice.h, branch v5.15.219

packet: use consistent hard_header_len in non-ring send paths

2026-08-27T12:28:19+00:00

[ Upstream commit 03390aa32e669cc4ecd7d34108e2e1afc13d689d ] packet_snd() reads dev->hard_header_len multiple times while allocating and constructing an skb. Device reconfiguration can change this value concurrently, for example through bonding device type changes. For SOCK_RAW, packet_snd() can save a larger value in reserve and later allocate headroom using a smaller value. Moving skb->data back by reserve then places it before skb->head, and the following copy from userspace can attempt an out-of-bounds write. packet_sendmsg_spkt() has the same issue because it calculates its reservation and header offset from separate reads before dropping the RCU read lock to allocate the skb. Add LL_RESERVED_SPACE_EX() for callers that already saved a header length. Read hard_header_len once in packet_snd() and use it for allocation and construction. In packet_sendmsg_spkt(), preserve the allocation-time value through the device lookup retry. The separate SOCK_DGRAM consistency problem between hard_header_len and header_ops->create is not addressed here. Fixes: b84bbaf7a6c8 ("packet: in packet_snd start writing at link layer allocation") Cc: stable@vger.kernel.org Signed-off-by: Qihang Tang Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20260805125729.19220-3-q.h.hack.winter@gmail.com Signed-off-by: Jakub Kicinski Stable-dep-of: 21b5953e7494 ("packet: use consistent hard_header_len in TX_RING send path") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

net: remove CAP_SYS_RAWIO zero-padding in dev_validate_header

2026-08-19T15:14:15+00:00

commit 3b9a324e646d3657a8d9806dfbfe4f3e4066e882 upstream. dev_validate_header() reads dev->hard_header_len directly when zero-padding short link layer headers for CAP_SYS_RAWIO holders: if (capable(CAP_SYS_RAWIO)) { memset(ll_header + len, 0, dev->hard_header_len - len); return true; } Packet send paths call dev_validate_header() on skbs whose headroom was allocated from an earlier hard_header_len read. If the device is reconfigured so that dev->hard_header_len increases before validation, the memset writes past the reserved buffer, an out-of-bounds write. This out-of-bounds write is masked in some SOCK_RAW paths today because the same concurrent increase can first make skb_push() exceed the reserved headroom and trigger skb_under_panic(). Remove the zero-padding branch before making those hard_header_len reads consistent, so the snapshot fixes do not turn a loud panic into a silent overwrite. This path is only reached for variable length L2 protocols, where len < hard_header_len but len >= min_header_len. No remaining in-tree variable length L2 protocol implements header_ops->validate, and the CAP_SYS_RAWIO bypass that zero-pads and accepts short headers has no real value beyond allowing testing of intentionally malformed input. Drop the CAP_SYS_RAWIO branch. The remaining reads of dev->hard_header_len in dev_validate_header() are comparisons only and have no memory safety impact. Suggested-by: Willem de Bruijn Fixes: 2793a23aacbd ("net: validate variable length ll headers") Cc: stable@vger.kernel.org Signed-off-by: Qihang Tang Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20260805125729.19220-2-q.h.hack.winter@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

netdev: preserve NETIF_F_ALL_FOR_ALL across TSO updates

2026-01-19T12:10:16+00:00

[ Upstream commit 02d1e1a3f9239cdb3ecf2c6d365fb959d1bf39df ] Directly increment the TSO features incurs a side effect: it will also directly clear the flags in NETIF_F_ALL_FOR_ALL on the master device, which can cause issues such as the inability to enable the nocache copy feature on the bonding driver. The fix is to include NETIF_F_ALL_FOR_ALL in the update mask, thereby preventing it from being cleared. Fixes: b0ce3508b25e ("bonding: allow TSO being set on bonding master") Signed-off-by: Di Zhu Link: https://patch.msgid.link/20251224012224.56185-1-zhud@hygon.cn Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: add ndo_fdb_del_bulk

2025-10-29T13:03:11+00:00

[ Upstream commit 1306d5362a591493a2d07f685ed2cc480dcda320 ] Add a new netdev op called ndo_fdb_del_bulk, it will be later used for driver-specific bulk delete implementation dispatched from rtnetlink. The first user will be the bridge, we need it to signal to rtnetlink from the driver that we support bulk delete operation (NLM_F_BULK). Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller Stable-dep-of: bf29555f5bdc ("rtnetlink: Allow deleting FDB entries in user namespace") Signed-off-by: Sasha Levin

net: Add non-RCU dev_getbyhwaddr() helper

2025-03-13T11:50:53+00:00

[ Upstream commit 4b5a28b38c4a0106c64416a1b2042405166b26ce ] Add dedicated helper for finding devices by hardware address when holding rtnl_lock, similar to existing dev_getbyhwaddr_rcu(). This prevents PROVE_LOCKING warnings when rtnl_lock is held but RCU read lock is not. Extract common address comparison logic into dev_addr_cmp(). The context about this change could be found in the following discussion: Link: https://lore.kernel.org/all/20250206-scarlet-ermine-of-improvement-1fcac5@leitao/ Cc: kuniyu@amazon.com Cc: ushankar@purestorage.com Suggested-by: Eric Dumazet Signed-off-by: Breno Leitao Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250218-arm_fix_selftest-v5-1-d3d6892db9e1@debian.org Signed-off-by: Jakub Kicinski Stable-dep-of: 4eae0ee0f1e6 ("arp: switch to dev_getbyhwaddr() in arp_req_set_public()") Signed-off-by: Sasha Levin

net: add dev_net_rcu() helper

2025-03-13T11:50:42+00:00

[ Upstream commit 482ad2a4ace2740ca0ff1cbc8f3c7f862f3ab507 ] dev->nd_net can change, readers should either use rcu_read_lock() or RTNL. We currently use a generic helper, dev_net() with no debugging support. We probably have many hidden bugs. Add dev_net_rcu() helper for callers using rcu_read_lock() protection. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250205155120.1676781-2-edumazet@google.com Signed-off-by: Jakub Kicinski Stable-dep-of: dd205fcc33d9 ("ipv4: use RCU protection in rt_is_expired()") Signed-off-by: Sasha Levin

net: add DEV_STATS_READ() helper

2023-11-20T10:08:16+00:00

[ Upstream commit 0b068c714ca9479d2783cc333fff5bc2d4a6d45c ] Companion of DEV_STATS_INC() & DEV_STATS_ADD(). This is going to be used in the series. Use it in macsec_get_stats64(). Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Stable-dep-of: ff672b9ffeb3 ("ipvlan: properly track tx_errors") Signed-off-by: Sasha Levin

net: introduce a function to check if a netdev name is in use

2023-10-25T09:59:01+00:00

[ Upstream commit 75ea27d0d62281c31ee259c872dfdeb072cf5e39 ] __dev_get_by_name is currently used to either retrieve a net device reference using its name or to check if a name is already used by a registered net device (per ns). In the later case there is no need to return a reference to a net device. Introduce a new helper, netdev_name_in_use, to check if a name is currently used by a registered net device without leaking a reference the corresponding net device. This helper uses netdev_name_node_lookup instead of __dev_get_by_name as we don't need the extra logic retrieving a reference to the corresponding net device. Signed-off-by: Antoine Tenart Signed-off-by: David S. Miller Stable-dep-of: 311cca40661f ("net: fix ifname in netlink ntf during netns move") Signed-off-by: Sasha Levin

bpf: Fix bpf socket lookup from tc/xdp to respect socket VRF bindings

2023-07-23T11:46:54+00:00

[ Upstream commit 9a5cb79762e0eda17ca15c2a6eaca4622383c21c ] When calling bpf_sk_lookup_tcp(), bpf_sk_lookup_udp() or bpf_skc_lookup_tcp() from tc/xdp ingress, VRF socket bindings aren't respoected, i.e. unbound sockets are returned, and bound sockets aren't found. VRF binding is determined by the sdif argument to sk_lookup(), however when called from tc the IP SKB control block isn't initialized and thus inet{,6}_sdif() always returns 0. Fix by calculating sdif for the tc/xdp flows by observing the device's l3 enslaved state. The cg/sk_skb hooking points which are expected to support inet{,6}_sdif() pass sdif=-1 which makes __bpf_skc_lookup() use the existing logic. Fixes: 6acc9b432e67 ("bpf: Add helper to retrieve socket in BPF") Signed-off-by: Gilad Sever Signed-off-by: Daniel Borkmann Reviewed-by: Shmulik Ladkani Reviewed-by: Eyal Birger Acked-by: Stanislav Fomichev Cc: David Ahern Link: https://lore.kernel.org/bpf/20230621104211.301902-4-gilad9366@gmail.com Signed-off-by: Sasha Levin

Remove DECnet support from kernel

2023-06-21T13:59:15+00:00

commit 1202cdd665315c525b5237e96e0bedc76d7e754f upstream. DECnet is an obsolete network protocol that receives more attention from kernel janitors than users. It belongs in computer protocol history museum not in Linux kernel. It has been "Orphaned" in kernel since 2010. The iproute2 support for DECnet was dropped in 5.0 release. The documentation link on Sourceforge says it is abandoned there as well. Leave the UAPI alone to keep userspace programs compiling. This means that there is still an empty neighbour table for AF_DECNET. The table of /proc/sys/net entries was updated to match current directories and reformatted to be alphabetical. Signed-off-by: Stephen Hemminger Acked-by: David Ahern Acked-by: Nikolay Aleksandrov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman