CVE-2024-42082

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.