kernel/linux.git/net/ipv4/devinet.c, branch v7.2-rc2

ipv4: handle devconf post-set actions on netlink updates

2026-06-13T21:15:53+00:00

When IPv4 device configuration parameters are updated via netlink, the kernel currently only updates the value. This bypasses several post-modification actions that occur when these same parameters are updated via sysctl, such as flushing the routing cache or emitting RTM_NEWNETCONF notifications. This patch addresses the inconsistency by calling the devinet_conf_post_set() helper inside inet_set_link_af(). If a flush is required, we defer it until the netlink attribute parsing loop completes. This ensures consistent behavior and side-effects for devconf changes, regardless of whether they are initiated via sysctl or netlink. Reviewed-by: Nicolas Dichtel Signed-off-by: Fernando Fernandez Mancera Link: https://patch.msgid.link/20260609204520.4670-2-fmancera@suse.de Signed-off-by: Jakub Kicinski

ipv4: centralize devconf sysctl handling

2026-06-13T21:15:53+00:00

The logic for handling IPv4 devconf sysctls is scattered. Notification and cache flushes are managed in devinet_conf_proc(), while a separate ipv4_doint_and_flush() function and DEVINET_SYSCTL_FLUSHING_ENTRY macro is used for properties that solely require a cache flush. This patch refactors the sysctl handling by introducing a centralized helper, devinet_conf_post_set(). This new function evaluates the changed attribute and handles all necessary operations like triggering netlink notifications. It returns a boolean indicating whether a routing cache flush is required. Note that the boolean is necessary as this function will be re-used for netlink IPv4 devconf handling where the cache flushing must wait until all the attributes have been processed. Finally, this is introducing a small change in behavior for IPV4_DEVCONF_ROUTE_LOCALNET. As commit d0daebc3d622 ("ipv4: Add interface option to enable routing of 127.0.0.0/8") intended, the cache flush should only be performed when ROUTE_LOCALNET changes from 1 to 0. Unfortunately, this was not true because while implementing it the DEVINET_SYSCTL_FLUSHING_ENTRY was used for the attribute, making the code related to it on devinet_conf_proc() dead. IPV4_DEVCONF_FORWARDING is still being handled separately as it requires more operations. Reviewed-by: Nicolas Dichtel Signed-off-by: Fernando Fernandez Mancera Link: https://patch.msgid.link/20260609204520.4670-1-fmancera@suse.de Signed-off-by: Jakub Kicinski

ipv4: validate IPV4_DEVCONF attributes properly

2026-03-14T16:52:30+00:00

As the IPV4_DEVCONF netlink attributes are not being validated, it is possible to use netlink to set read-only values like mc_forwarding. In addition, valid ranges are not being validated neither but that is less relevant as they aren't in sysctl. To avoid similar situations in the future, define a NLA policy for IPV4_DEVCONF attributes which are nested in IFLA_INET_CONF. Signed-off-by: Fernando Fernandez Mancera Link: https://patch.msgid.link/20260312142637.5704-1-fmancera@suse.de Signed-off-by: Jakub Kicinski

Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL uses

2026-02-22T16:26:33+00:00

Conversion performed via this Coccinelle script: // SPDX-License-Identifier: GPL-2.0-only // Options: --include-headers-for-types --all-includes --include-headers --keep-comments virtual patch @gfp depends on patch && !(file in "tools") && !(file in "samples")@ identifier ALLOC = {kmalloc_obj,kmalloc_objs,kmalloc_flex, kzalloc_obj,kzalloc_objs,kzalloc_flex, kvmalloc_obj,kvmalloc_objs,kvmalloc_flex, kvzalloc_obj,kvzalloc_objs,kvzalloc_flex}; @@ ALLOC(... - , GFP_KERNEL ) $ make coccicheck MODE=patch COCCI=gfp.cocci Build and boot tested x86_64 with Fedora 42's GCC and Clang: Linux version 6.19.0+ (user@host) (gcc (GCC) 15.2.1 20260123 (Red Hat 15.2.1-7), GNU ld version 2.44-12.fc42) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Linux version 6.19.0+ (user@host) (clang version 20.1.8 (Fedora 20.1.8-4.fc42), LLD 20.1.8) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Signed-off-by: Kees Cook Signed-off-by: Linus Torvalds

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

ipv4: Fix NULL vs error pointer check in inet_blackhole_dev_init()

2025-09-03T23:58:44+00:00

The inetdev_init() function never returns NULL. Check for error pointers instead. Fixes: 22600596b675 ("ipv4: give an IPv4 dev to blackhole_netdev") Signed-off-by: Dan Carpenter Reviewed-by: Simon Horman Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/aLaQWL9NguWmeM1i@stanley.mountain Signed-off-by: Jakub Kicinski

ipv4: Use nlmsg_payload in devinet file

2025-04-17T01:33:02+00:00

Leverage the new nlmsg_payload() helper to avoid checking for message size and then reading the nlmsg data. Signed-off-by: Breno Leitao Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250415-nlmsg_v2-v1-4-a1c75d493fd7@debian.org Signed-off-by: Jakub Kicinski

net: switch to netif_disable_lro in inetdev_init

2025-04-03T22:32:08+00:00

Cosmin reports the following deadlock: dump_stack_lvl+0x62/0x90 print_deadlock_bug+0x274/0x3b0 __lock_acquire+0x1229/0x2470 lock_acquire+0xb7/0x2b0 __mutex_lock+0xa6/0xd20 dev_disable_lro+0x20/0x80 inetdev_init+0x12f/0x1f0 inetdev_event+0x48b/0x870 notifier_call_chain+0x38/0xf0 netif_change_net_namespace+0x72e/0x9f0 do_setlink.isra.0+0xd5/0x1220 rtnl_newlink+0x7ea/0xb50 rtnetlink_rcv_msg+0x459/0x5e0 netlink_rcv_skb+0x54/0x100 netlink_unicast+0x193/0x270 netlink_sendmsg+0x204/0x450 Switch to netif_disable_lro which assumes the caller holds the instance lock. inetdev_init is called for blackhole device (which sw device and doesn't grab instance lock) and from REGISTER/UNREGISTER notifiers. We already hold the instance lock for REGISTER notifier during netns change and we'll soon hold the lock during other paths. Reviewed-by: Jakub Kicinski Reported-by: Cosmin Ratiu Fixes: ad7c7b2172c3 ("net: hold netdev instance lock during sysfs operations") Signed-off-by: Stanislav Fomichev Link: https://patch.msgid.link/20250401163452.622454-2-sdf@fomichev.me Signed-off-by: Jakub Kicinski

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

2025-02-13T20:43:30+00:00

Cross-merge networking fixes after downstream PR (net-6.14-rc3). No conflicts or adjacent changes. Signed-off-by: Jakub Kicinski