CVE-2025-71091: team: fix check for port enabled in team_queue_override_port_prio_changed()

In the Linux kernel, the following vulnerability has been resolved:

team: fix check for port enabled in teamqueueoverrideportpriochanged()

There has been a syzkaller bug reported recently with the following trace:

listdel corruption, ffff888058bea080->prev is LISTPOISON2 (dead000000000122) ------------[ cut here ]------------ kernel BUG at lib/listdebug.c:59! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 3 UID: 0 PID: 21246 Comm: syz.0.2928 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:listdelentryvalidorreport+0x13e/0x200 lib/listdebug.c:59 Code: 48 c7 c7 e0 71 f0 8b e8 30 08 ef fc 90 0f 0b 48 89 ef e8 a5 02 55 fd 48 89 ea 48 89 de 48 c7 c7 40 72 f0 8b e8 13 08 ef fc 90 <0f> 0b 48 89 ef e8 88 02 55 fd 48 89 ea 48 b8 00 00 00 00 00 fc ff RSP: 0018:ffffc9000d49f370 EFLAGS: 00010286 RAX: 000000000000004e RBX: ffff888058bea080 RCX: ffffc9002817d000 RDX: 0000000000000000 RSI: ffffffff819becc6 RDI: 0000000000000005 RBP: dead000000000122 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000080000000 R11: 0000000000000001 R12: ffff888039e9c230 R13: ffff888058bea088 R14: ffff888058bea080 R15: ffff888055461480 FS: 00007fbbcfe6f6c0(0000) GS:ffff8880d6d0a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3afcb0 CR3: 00000000382c7000 CR4: 0000000000352ef0 Call Trace: <TASK> listdelentryvalid include/linux/list.h:132 [inline] listdelentry include/linux/list.h:223 [inline] listdelrcu include/linux/rculist.h:178 [inline] teamqueueoverrideportdel drivers/net/team/teamcore.c:826 [inline] teamqueueoverrideportdel drivers/net/team/teamcore.c:821 [inline] teamqueueoverrideportpriochanged drivers/net/team/teamcore.c:883 [inline] teampriorityoptionset+0x171/0x2f0 drivers/net/team/teamcore.c:1534 teamoptionset drivers/net/team/teamcore.c:376 [inline] teamnloptionssetdoit+0x8ae/0xe60 drivers/net/team/teamcore.c:2653 genlfamilyrcvmsgdoit+0x209/0x2f0 net/netlink/genetlink.c:1115 genlfamilyrcvmsg net/netlink/genetlink.c:1195 [inline] genlrcvmsg+0x55c/0x800 net/netlink/genetlink.c:1210 netlinkrcvskb+0x158/0x420 net/netlink/afnetlink.c:2552 genlrcv+0x28/0x40 net/netlink/genetlink.c:1219 netlinkunicastkernel net/netlink/afnetlink.c:1320 [inline] netlinkunicast+0x5aa/0x870 net/netlink/afnetlink.c:1346 netlinksendmsg+0x8c8/0xdd0 net/netlink/afnetlink.c:1896 socksendmsgnosec net/socket.c:727 [inline] socksendmsg net/socket.c:742 [inline] syssendmsg+0xa98/0xc70 net/socket.c:2630 syssendmsg+0x134/0x1d0 net/socket.c:2684 syssendmsg+0x16d/0x220 net/socket.c:2716 dosyscallx64 arch/x86/entry/syscall64.c:63 [inline] dosyscall64+0xcd/0xfa0 arch/x86/entry/syscall64.c:94 entrySYSCALL64afterhwframe+0x77/0x7f

The problem is in this flow: 1) Port is enabled, queueid != 0, in qomlist 2) Port gets disabled -> teamportdisable() -> teamqueueoverrideportdel() -> del (removed from list) 3) Port is disabled, queueid != 0, not in any list 4) Priority changes -> teamqueueoverrideportpriochanged() -> checks: port disabled && queueid != 0 -> calls del - hits the BUG as it is removed already

To fix this, change the check in teamqueueoverrideportpriochanged() so it returns early if port is not enabled.