Allocation of Resources Without Limits or Throttling Affecting kernel-rt package, versions *

Note: Versions mentioned in the description apply only to the upstream kernel-rt package and not the kernel-rt package as distributed by RHEL. See How to fix? for RHEL:7 relevant fixed versions and status.

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

xdp: Remove WARN() from __xdp_reg_mem_model()

syzkaller reports a warning in __xdp_reg_mem_model().

The warning occurs only if __mem_id_init_hash_table() returns an error. It returns the error in two cases:

1. memory allocation fails;
2. rhashtable_init() fails when some fields of rhashtable_params struct are not initialized properly.

The second case cannot happen since there is a static const rhashtable_params struct with valid fields. So, warning is only triggered when there is a problem with memory allocation.

Thus, there is no sense in using WARN() to handle this error and it can be safely removed.

WARNING: CPU: 0 PID: 5065 at net/core/xdp.c:299 __xdp_reg_mem_model+0x2d9/0x650 net/core/xdp.c:299

CPU: 0 PID: 5065 Comm: syz-executor883 Not tainted 6.8.0-syzkaller-05271-gf99c5f563c17 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:__xdp_reg_mem_model+0x2d9/0x650 net/core/xdp.c:299

Call Trace: xdp_reg_mem_model+0x22/0x40 net/core/xdp.c:344 xdp_test_run_setup net/bpf/test_run.c:188 [inline] bpf_test_run_xdp_live+0x365/0x1e90 net/bpf/test_run.c:377 bpf_prog_test_run_xdp+0x813/0x11b0 net/bpf/test_run.c:1267 bpf_prog_test_run+0x33a/0x3b0 kernel/bpf/syscall.c:4240 __sys_bpf+0x48d/0x810 kernel/bpf/syscall.c:5649 __do_sys_bpf kernel/bpf/syscall.c:5738 [inline] __se_sys_bpf kernel/bpf/syscall.c:5736 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5736 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75

Found by Linux Verification Center (linuxtesting.org) with syzkaller.

• https://access.redhat.com/security/cve/CVE-2024-42082
• https://git.kernel.org/stable/c/1095b8efbb13a6a5fa583ed373ee1ccab29da2d0
• https://git.kernel.org/stable/c/14e51ea78b4ccacb7acb1346b9241bb790a2054c
• https://git.kernel.org/stable/c/1d3e3b3aa2cbe9bc7db9a7f8673a9fa6d2990d54
• https://git.kernel.org/stable/c/4e0c539ee265d5c6e7fa7d229cd4aa7bc01816e2
• https://git.kernel.org/stable/c/7e9f79428372c6eab92271390851be34ab26bfb4
• https://git.kernel.org/stable/c/f92298b0467fd77edc4c1a2c3e48833e69840ec4