Use of Uninitialized Resource Affecting kernel-64k-debug-devel package, versions <0:5.14.0-427.40.1.el9_4

Note: Versions mentioned in the description apply only to the upstream kernel-64k-debug-devel package and not the kernel-64k-debug-devel package as distributed by AlmaLinux. See How to fix? for AlmaLinux:9 relevant fixed versions and status.

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

sched: act_ct: take care of padding in struct zones_ht_key

Blamed commit increased lookup key size from 2 bytes to 16 bytes, because zones_ht_key got a struct net pointer.

Make sure rhashtable_lookup() is not using the padding bytes which are not initialized.

BUG: KMSAN: uninit-value in rht_ptr_rcu include/linux/rhashtable.h:376 [inline] BUG: KMSAN: uninit-value in __rhashtable_lookup include/linux/rhashtable.h:607 [inline] BUG: KMSAN: uninit-value in rhashtable_lookup include/linux/rhashtable.h:646 [inline] BUG: KMSAN: uninit-value in rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline] BUG: KMSAN: uninit-value in tcf_ct_flow_table_get+0x611/0x2260 net/sched/act_ct.c:329 rht_ptr_rcu include/linux/rhashtable.h:376 [inline] __rhashtable_lookup include/linux/rhashtable.h:607 [inline] rhashtable_lookup include/linux/rhashtable.h:646 [inline] rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline] tcf_ct_flow_table_get+0x611/0x2260 net/sched/act_ct.c:329 tcf_ct_init+0xa67/0x2890 net/sched/act_ct.c:1408 tcf_action_init_1+0x6cc/0xb30 net/sched/act_api.c:1425 tcf_action_init+0x458/0xf00 net/sched/act_api.c:1488 tcf_action_add net/sched/act_api.c:2061 [inline] tc_ctl_action+0x4be/0x19d0 net/sched/act_api.c:2118 rtnetlink_rcv_msg+0x12fc/0x1410 net/core/rtnetlink.c:6647 netlink_rcv_skb+0x375/0x650 net/netlink/af_netlink.c:2550 rtnetlink_rcv+0x34/0x40 net/core/rtnetlink.c:6665 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline] netlink_unicast+0xf52/0x1260 net/netlink/af_netlink.c:1357 netlink_sendmsg+0x10da/0x11e0 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x30f/0x380 net/socket.c:745 ____sys_sendmsg+0x877/0xb60 net/socket.c:2597 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2651 __sys_sendmsg net/socket.c:2680 [inline] __do_sys_sendmsg net/socket.c:2689 [inline] __se_sys_sendmsg net/socket.c:2687 [inline] __x64_sys_sendmsg+0x307/0x4a0 net/socket.c:2687 x64_sys_call+0x2dd6/0x3c10 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Local variable key created at: tcf_ct_flow_table_get+0x4a/0x2260 net/sched/act_ct.c:324 tcf_ct_init+0xa67/0x2890 net/sched/act_ct.c:1408

• https://errata.almalinux.org/9/ALSA-2024-8162.html
• https://access.redhat.com/security/cve/CVE-2024-42272
• https://access.redhat.com/errata/RHSA-2024:8162
• https://git.kernel.org/stable/c/2191a54f63225b548fd8346be3611c3219a24738
• https://git.kernel.org/stable/c/3a5b68869dbe14f1157c6a24ac71923db060eeab
• https://git.kernel.org/stable/c/3ddefcb8f75e312535e2e7d5fef9932019ba60f2
• https://git.kernel.org/stable/c/7c03ab555eb1ba26c77fd7c25bdf44a0ac23edee
• https://git.kernel.org/stable/c/d06daf0ad645d9225a3ff6958dd82e1f3988fa64
• https://git.kernel.org/stable/c/d7cc186d0973afce0e1237c37f7512c01981fb79