kernel/linux.git/net/ipv4/arp.c, branch linux-7.1.y

net: remove ax25 and amateur radio (hamradio) subsystem

2026-04-23T17:24:02+00:00

Remove the amateur radio (AX.25, NET/ROM, ROSE) protocol implementation and all associated hamradio device drivers from the kernel tree. This set of protocols has long been a huge bug/syzbot magnet, and since nobody stepped up to help us deal with the influx of the AI-generated bug reports we need to move it out of tree to protect our sanity. The code is moved to an out-of-tree repo: https://github.com/linux-netdev/mod-orphan if it's cleaned up and reworked there we can accept it back. Minimal stub headers are kept for include/net/ax25.h (AX25_P_IP, AX25_ADDR_LEN, ax25_address) and include/net/rose.h (ROSE_ADDR_LEN) so that the conditional integration code in arp.c and tun.c continues to compile and work when the out-of-tree modules are loaded. Signed-off-by: Jakub Kicinski Acked-by: Greg Kroah-Hartman Acked-by: Stephen Hemminger Acked-by: Carlos Bilbao Reviewed-by: Simon Horman Reviewed-by: Kuniyuki Iwashima Acked-by: Toke Høiland-Jørgensen Link: https://patch.msgid.link/20260421021824.1293976-1-kuba@kernel.org Signed-off-by: Paolo Abeni

kernel.h: drop hex.h and update all hex.h users

2026-01-21T03:44:19+00:00

Remove from and update all users/callers of hex.h interfaces to directly #include as part of the process of putting kernel.h on a diet. Removing hex.h from kernel.h means that 36K C source files don't have to pay the price of parsing hex.h for the roughly 120 C source files that need it. This change has been build-tested with allmodconfig on most ARCHes. Also, all users/callers of in the entire source tree have been updated if needed (if not already #included). Link: https://lkml.kernel.org/r/20251215005206.2362276-1-rdunlap@infradead.org Signed-off-by: Randy Dunlap Reviewed-by: Andy Shevchenko Cc: Ingo Molnar Cc: Yury Norov (NVIDIA) Signed-off-by: Andrew Morton

arp: do not assume dev_hard_header() does not change skb->head

2026-01-08T17:04:24+00:00

arp_create() is the only dev_hard_header() caller making assumption about skb->head being unchanged. A recent commit broke this assumption. Initialize @arp pointer after dev_hard_header() call. Fixes: db5b4e39c4e6 ("ip6_gre: make ip6gre_header() robust") Reported-by: syzbot+58b44a770a1585795351@syzkaller.appspotmail.com Signed-off-by: Eric Dumazet Link: https://patch.msgid.link/20260107212250.384552-1-edumazet@google.com Signed-off-by: Jakub Kicinski

net: Convert struct sockaddr to fixed-size "sa_data[14]"

2025-11-05T03:10:33+00:00

Revert struct sockaddr from flexible array to fixed 14-byte "sa_data", to solve over 36,000 -Wflex-array-member-not-at-end warnings, since struct sockaddr is embedded within many network structs. With socket/proto sockaddr-based internal APIs switched to use struct sockaddr_unsized, there should be no more uses of struct sockaddr that depend on reading beyond the end of struct sockaddr::sa_data that might trigger bounds checking. Comparing an x86_64 "allyesconfig" vmlinux build before and after this patch showed no new "ud1" instructions from CONFIG_UBSAN_BOUNDS nor any new "field-spanning" memcpy CONFIG_FORTIFY_SOURCE instrumentations. Cc: Gustavo A. R. Silva Signed-off-by: Kees Cook Link: https://patch.msgid.link/20251104002617.2752303-8-kees@kernel.org Signed-off-by: Jakub Kicinski

neighbour: Convert rwlock of struct neigh_table to spinlock.

2025-10-25T00:57:20+00:00

Only neigh_for_each() and neigh_seq_start/stop() are on the reader side of neigh_table.lock. Let's convert rwlock to the plain spinlock. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20251022054004.2514876-6-kuniyu@google.com Signed-off-by: Jakub Kicinski

net: set net.core.rmem_max and net.core.wmem_max to 4 MB

2025-08-21T02:35:00+00:00

SO_RCVBUF and SO_SNDBUF have limited range today, unless distros or system admins change rmem_max and wmem_max. Even iproute2 uses 1 MB SO_RCVBUF which is capped by the kernel. Decouple [rw]mem_max and [rw]mem_default and increase [rw]mem_max to 4 MB. Before: $ sysctl net.core.rmem_default net.core.rmem_max net.core.wmem_default net.core.wmem_max net.core.rmem_default = 212992 net.core.rmem_max = 212992 net.core.wmem_default = 212992 net.core.wmem_max = 212992 After: $ sysctl net.core.rmem_default net.core.rmem_max net.core.wmem_default net.core.wmem_max net.core.rmem_default = 212992 net.core.rmem_max = 4194304 net.core.wmem_default = 212992 net.core.wmem_max = 4194304 Signed-off-by: Eric Dumazet Reviewed-by: Neal Cardwell Link: https://patch.msgid.link/20250819174030.1986278-1-edumazet@google.com Signed-off-by: Jakub Kicinski

neighbour: Update pneigh_entry in pneigh_create().

2025-07-17T23:25:22+00:00

neigh_add() updates pneigh_entry() found or created by pneigh_create(). This update is serialised by RTNL, but we will remove it. Let's move the update part to pneigh_create() and make it return errno instead of a pointer of pneigh_entry. Now, the pneigh code is RTNL free. Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250716221221.442239-16-kuniyu@google.com Signed-off-by: Jakub Kicinski

neighbour: Split pneigh_lookup().

2025-07-17T23:25:20+00:00

pneigh_lookup() has ASSERT_RTNL() in the middle of the function, which is confusing. When called with the last argument, creat, 0, pneigh_lookup() literally looks up a proxy neighbour entry. This is the case of the reader path as the fast path and RTM_GETNEIGH. pneigh_lookup(), however, creates a pneigh_entry when called with creat 1 from RTM_NEWNEIGH and SIOCSARP, which require RTNL. Let's split pneigh_lookup() into two functions. We will convert all the reader paths to RCU, and read_lock_bh(&tbl->lock) in the new pneigh_lookup() will be dropped. Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250716221221.442239-6-kuniyu@google.com Signed-off-by: Jakub Kicinski

net: arp: use kfree_skb_reason() in arp_rcv()

2025-06-14T00:30:02+00:00

Replace kfree_skb() with kfree_skb_reason() in arp_rcv(). Signed-off-by: Qiu Yutan Signed-off-by: Jiang Kun Link: https://patch.msgid.link/20250612110259698Q2KNNOPQhnIApRskKN3Hi@zte.com.cn Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2025-02-20T18:37:30+00:00

Cross-merge networking fixes after downstream PR (net-6.14-rc4). No conflicts or adjacent changes. Signed-off-by: Jakub Kicinski