CVE-2024-42082: xdp: Remove WARN() from __xdp_reg_mem_model()

Description

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 k...

Classification

CVE ID: CVE-2024-42082

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 5.08% (scored less or equal to compared to others)

EPSS Date: 2025-02-04 (when was this score calculated)

References

https://git.kernel.org/stable/c/1095b8efbb13a6a5fa583ed373ee1ccab29da2d0
https://git.kernel.org/stable/c/1d3e3b3aa2cbe9bc7db9a7f8673a9fa6d2990d54
https://git.kernel.org/stable/c/4e0c539ee265d5c6e7fa7d229cd4aa7bc01816e2
https://git.kernel.org/stable/c/14e51ea78b4ccacb7acb1346b9241bb790a2054c
https://git.kernel.org/stable/c/f92298b0467fd77edc4c1a2c3e48833e69840ec4
https://git.kernel.org/stable/c/7e9f79428372c6eab92271390851be34ab26bfb4

Timeline