ALSA-2024:5928 — Important: kernel security update

Affected: AlmaLinux:9: bpftool, AlmaLinux:9: kernel, AlmaLinux:9: kernel-64k, AlmaLinux:9: kernel-64k-core, AlmaLinux:9: kernel-64k-debug, AlmaLinux:9: kernel-64k-debug-core, AlmaLinux:9: kernel-64k-debug-devel, AlmaLinux:9: kernel-64k-debug-devel-matched, AlmaLinux:9: kernel-64k-debug-modules, AlmaLinux:9: kernel-64k-debug-modules-core and 52 more

The kernel packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

* kernel: nftables: nft_set_rbtree skip end interval element from gc (CVE-2024-26581) * kernel: netfilter: nft_limit: reject configurations that cause integer overflow (CVE-2024-26668) * kernel: vfio/pci: Lock external INTx masking ops (CVE-2024-26810) * kernel: net: ice: Fix potential NULL pointer dereference in ice_bridge_setlink() (CVE-2024-26855) * kernel: x86/xen: Add some null pointer checking to smp.c (CVE-2024-26908) * kernel: netfilter: nf_tables: release mutex after nft_gc_seq_end from abort path (CVE-2024-26925) * kernel: netfilter: nf_tables: Fix potential data-race in __nft_expr_type_get() (CVE-2024-27020) * kernel: netfilter: nf_tables: Fix potential data-race in __nft_obj_type_get() (CVE-2024-27019) * kernel: netfilter: flowtable: validate pppoe header (CVE-2024-27016) * kernel: netfilter: bridge: confirm multicast packets before passing them up the stack (CVE-2024-27415) * kernel: netfilter: bridge: replace physindev with physinif in nf_bridge_info (CVE-2024-35839) * kernel: netfilter: nf_tables: Fix potential data-race in __nft_flowtable_type_get() (CVE-2024-35898) * kernel: netfilter: nf_tables: discard table flag update with pending basechain deletion (CVE-2024-35897) * kernel: netfilter: validate user input for expected length (CVE-2024-35896) * kernel: netfilter: complete validation of user input (CVE-2024-35962) *…

CVE-2024-41041 — udp: Set SOCK_RCU_FREE earlier in udp_lib_get_port().

Affected: Linux

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

udp: Set SOCK_RCU_FREE earlier in udp_lib_get_port().

syzkaller triggered the warning [0] in udp_v4_early_demux().

In udp_v[46]_early_demux() and sk_lookup(), we do not touch the refcount of the looked-up sk and use sock_pfree() as skb->destructor, so we check SOCK_RCU_FREE to ensure that the sk is safe to access during the RCU grace period.

Currently, SOCK_RCU_FREE is flagged for a bound socket after being put into the hash table. Moreover, the SOCK_RCU_FREE check is done too early in udp_v[46]_early_demux() and sk_lookup(), so there could be a small race window:

CPU1 CPU2 ---- ---- udp_v4_early_demux() udp_lib_get_port() | |- hlist_add_head_rcu() |- sk = __udp4_lib_demux_lookup() | |- DEBUG_NET_WARN_ON_ONCE(sk_is_refcounted(sk)); `- sock_set_flag(sk, SOCK_RCU_FREE)

We had the same bug in TCP and fixed it in commit 871019b22d1b ("net: set SOCK_RCU_FREE before inserting socket into hashtable").

Let's apply the same fix for UDP.

[0]: WARNING: CPU: 0 PID: 11198 at net/ipv4/udp.c:2599 udp_v4_early_demux+0x481/0xb70 net/ipv4/udp.c:2599 Modules linked in: CPU: 0 PID: 11198 Comm: syz-executor.1 Not tainted 6.9.0-g93bda33046e7 #13 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/…

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ALSA-2024:5928 — Important: kernel security update

CVE-2024-41041 — udp: Set SOCK_RCU_FREE earlier in udp_lib_get_port().