CVE-2023-52698: calipso: fix memory leak in netlbl_calipso_add_pass()

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

calipso: fix memory leak in netlblcalipsoaddpass()

If IPv6 support is disabled at boot (ipv6.disable=1), the calipsoinit() -> netlblcalipsoopsregister() function isn't called, and the netlblcalipsoopsget() function always returns NULL. In this case, the netlblcalipsoaddpass() function allocates memory for the doidef variable but doesn't free it with the calipsodoifree().

BUG: memory leak unreferenced object 0xffff888011d68180 (size 64): comm "syz-executor.1", pid 10746, jiffies 4295410986 (age 17.928s) hex dump (first 32 bytes): 00 00 00 00 02 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<...>] kmalloc include/linux/slab.h:552 [inline] [<...>] netlblcalipsoaddpass net/netlabel/netlabelcalipso.c:76 [inline] [<...>] netlblcalipsoadd+0x22e/0x4f0 net/netlabel/netlabelcalipso.c:111 [<...>] genlfamilyrcvmsgdoit+0x22f/0x330 net/netlink/genetlink.c:739 [<...>] genlfamilyrcvmsg net/netlink/genetlink.c:783 [inline] [<...>] genlrcvmsg+0x341/0x5a0 net/netlink/genetlink.c:800 [<...>] netlinkrcvskb+0x14d/0x440 net/netlink/afnetlink.c:2515 [<...>] genlrcv+0x29/0x40 net/netlink/genetlink.c:811 [<...>] netlinkunicastkernel net/netlink/afnetlink.c:1313 [inline] [<...>] netlinkunicast+0x54b/0x800 net/netlink/afnetlink.c:1339 [<...>] netlinksendmsg+0x90a/0xdf0 net/netlink/afnetlink.c:1934 [<...>] socksendmsgnosec net/socket.c:651 [inline] [<...>] socksendmsg+0x157/0x190 net/socket.c:671 [<...>] syssendmsg+0x712/0x870 net/socket.c:2342 [<...>] syssendmsg+0xf8/0x170 net/socket.c:2396 [<...>] syssendmsg+0xea/0x1b0 net/socket.c:2429 [<...>] dosyscall64+0x30/0x40 arch/x86/entry/common.c:46 [<...>] entrySYSCALL64afterhwframe+0x61/0xc6

Found by InfoTeCS on behalf of Linux Verification Center (linuxtesting.org) with Syzkaller

[PM: merged via the LSM tree at Jakub Kicinski request]