Commit 34b11cc56e43 for kernel

commit 34b11cc56e4369bc08b1f4c4a04222d75ed596ce
Author: Fedor Pchelkin <pchelkin@ispras.ru>
Date:   Mon Mar 16 13:38:25 2026 +0300

    net: macb: fix uninitialized rx_fs_lock

    If hardware doesn't support RX Flow Filters, rx_fs_lock spinlock is not
    initialized leading to the following assertion splat triggerable via
    set_rxnfc callback.

    INFO: trying to register non-static key.
    The code is fine but needs lockdep annotation, or maybe
    you didn't initialize this object before use?
    turning off the locking correctness validator.
    CPU: 1 PID: 949 Comm: syz.0.6 Not tainted 6.1.164+ #113
    Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014
    Call Trace:
     <TASK>
     __dump_stack lib/dump_stack.c:88 [inline]
     dump_stack_lvl+0x8d/0xba lib/dump_stack.c:106
     assign_lock_key kernel/locking/lockdep.c:974 [inline]
     register_lock_class+0x141b/0x17f0 kernel/locking/lockdep.c:1287
     __lock_acquire+0x74f/0x6c40 kernel/locking/lockdep.c:4928
     lock_acquire kernel/locking/lockdep.c:5662 [inline]
     lock_acquire+0x190/0x4b0 kernel/locking/lockdep.c:5627
     __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
     _raw_spin_lock_irqsave+0x33/0x50 kernel/locking/spinlock.c:162
     gem_del_flow_filter drivers/net/ethernet/cadence/macb_main.c:3562 [inline]
     gem_set_rxnfc+0x533/0xac0 drivers/net/ethernet/cadence/macb_main.c:3667
     ethtool_set_rxnfc+0x18c/0x280 net/ethtool/ioctl.c:961
     __dev_ethtool net/ethtool/ioctl.c:2956 [inline]
     dev_ethtool+0x229c/0x6290 net/ethtool/ioctl.c:3095
     dev_ioctl+0x637/0x1070 net/core/dev_ioctl.c:510
     sock_do_ioctl+0x20d/0x2c0 net/socket.c:1215
     sock_ioctl+0x577/0x6d0 net/socket.c:1320
     vfs_ioctl fs/ioctl.c:51 [inline]
     __do_sys_ioctl fs/ioctl.c:870 [inline]
     __se_sys_ioctl fs/ioctl.c:856 [inline]
     __x64_sys_ioctl+0x18c/0x210 fs/ioctl.c:856
     do_syscall_x64 arch/x86/entry/common.c:46 [inline]
     do_syscall_64+0x35/0x80 arch/x86/entry/common.c:76
     entry_SYSCALL_64_after_hwframe+0x6e/0xd8

    A more straightforward solution would be to always initialize rx_fs_lock,
    just like rx_fs_list.  However, in this case the driver set_rxnfc callback
    would return with a rather confusing error code, e.g. -EINVAL.  So deny
    set_rxnfc attempts directly if the RX filtering feature is not supported
    by hardware.

    Fixes: ae8223de3df5 ("net: macb: Added support for RX filtering")
    Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
    Link: https://patch.msgid.link/20260316103826.74506-2-pchelkin@ispras.ru
    Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 033cff571904..c16ac9c76aa3 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -3983,6 +3983,9 @@ static int gem_set_rxnfc(struct net_device *netdev, struct ethtool_rxnfc *cmd)
 	struct macb *bp = netdev_priv(netdev);
 	int ret;

+	if (!(netdev->hw_features & NETIF_F_NTUPLE))
+		return -EOPNOTSUPP;
+
 	switch (cmd->cmd) {
 	case ETHTOOL_SRXCLSRLINS:
 		if ((cmd->fs.location >= bp->max_tuples)