{"cve":"CVE-2024-41048","nvd":{"published":"2024-07-29T15:15:13.103","modified":"2026-10-30T13:17:31.107","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nskmsg: Skip zero length skb in sk_msg_recvmsg\n\nWhen running BPF selftests (./test_progs -t sockmap_basic) on a Loongarch\nplatform, the following kernel panic occurs:\n\n  [...]\n  Oops[#1]:\n  CPU: 22 PID: 2824 Comm: test_progs Tainted: G           OE  6.10.0-rc2+ #18\n  Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018\n     ... ...\n     ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560\n    ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0\n   CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)\n   PRMD: 0000000c (PPLV0 +PIE +PWE)\n   EUEN: 00000007 (+FPE +SXE +ASXE -BTE)\n   ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)\n  ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)\n   BADV: 0000000000000040\n   PRID: 0014c011 (Loongson-64bit, Loongson-3C5000)\n  Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack\n  Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...)\n  Stack : ...\n  Call Trace:\n  [<9000000004162774>] copy_page_to_iter+0x74/0x1c0\n  [<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560\n  [<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0\n  [<90000000049aae34>] inet_recvmsg+0x54/0x100\n  [<900000000481ad5c>] sock_recvmsg+0x7c/0xe0\n  [<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0\n  [<900000000481e27c>] sys_recvfrom+0x1c/0x40\n  [<9000000004c076ec>] do_syscall+0x8c/0xc0\n  [<9000000003731da4>] handle_syscall+0xc4/0x160\n  Code: ...\n  ---[ end trace 0000000000000000 ]---\n  Kernel panic - not syncing: Fatal exception\n  Kernel relocated by 0x3510000\n   .text @ 0x9000000003710000\n   .data @ 0x9000000004d70000\n   .bss  @ 0x9000000006469400\n  ---[ end Kernel panic - not syncing: Fatal exception ]---\n  [...]\n\nThis crash happens every time when running sockmap_skb_verdict_shutdown\nsubtest in sockmap_basic.\n\nThis crash is because a NULL pointer is passed to page_address() in the\nsk_msg_recvmsg(). Due to the different implementations depending on the\narchitecture, page_address(NULL) will trigger a panic on Loongarch\nplatform but not on x86 platform. So this bug was hidden on x86 platform\nfor a while, but now it is exposed on Loongarch platform. The root cause\nis that a zero length skb (skb->len == 0) was put on the queue.\n\nThis zero length skb is a TCP FIN packet, which was sent by shutdown(),\ninvoked in test_sockmap_skb_verdict_shutdown():\n\n\tshutdown(p1, SHUT_WR);\n\nIn this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no\npage is put to this sge (see sg_set_page in sg_set_page), but this empty\nsge is queued into ingress_msg list.\n\nAnd in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by\nsg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it\nto kmap_local_page() and to page_address(), then kernel panics.\n\nTo solve this, we should skip this zero length skb. So in sk_msg_recvmsg(),\nif copy is zero, that means it's a zero length skb, skip invoking\ncopy_page_to_iter(). We are using the EFAULT return triggered by\ncopy_page_to_iter to check for is_fin in tcp_bpf.c.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/195b7bcdfc5adc5b2468f279dd9eb7eebd2e7632","https://git.kernel.org/stable/c/b180739b45a38b4caa88fe16bb5273072e6613dc","https://git.kernel.org/stable/c/ddf6f5179638ef0716d32e8fc04a72822b135351","https://git.kernel.org/stable/c/f0c18025693707ec344a70b6887f7450bf4c826b","https://git.kernel.org/stable/c/f8bd689f37f4198a4c61c4684f591ba639595b97"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-30T13:47:47.119061695+00:00"},"epss":{"cve":"CVE-2024-41048","score":0.00799,"percentile":0.56522,"date":"2026-10-30"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}