{ "data_version": "4.0", "data_type": "CVE", "data_format": "MITRE", "CVE_data_meta": { "ID": "CVE-2024-41048", "ASSIGNER": "cve@kernel.org", "STATE": "PUBLIC" }, "description": { "description_data": [ { "lang": "eng", "value": "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." } ] }, "problemtype": { "problemtype_data": [ { "description": [ { "lang": "eng", "value": "n/a" } ] } ] }, "affects": { "vendor": { "vendor_data": [ { "vendor_name": "Linux", "product": { "product_data": [ { "product_name": "Linux", "version": { "version_data": [ { "version_affected": "<", "version_name": "604326b41a6f", "version_value": "195b7bcdfc5a" }, { "version_value": "not down converted", "x_cve_json_5_version_data": { "versions": [ { "version": "4.20", "status": "affected" }, { "version": "0", "lessThan": "4.20", "status": "unaffected", "versionType": "custom" }, { "version": "5.15.163", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.1.100", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.6.41", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.9.10", "lessThanOrEqual": "6.9.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.10", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ], "defaultStatus": "affected" } } ] } } ] } } ] } }, "references": { "reference_data": [ { "url": "https://git.kernel.org/stable/c/195b7bcdfc5adc5b2468f279dd9eb7eebd2e7632", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/195b7bcdfc5adc5b2468f279dd9eb7eebd2e7632" }, { "url": "https://git.kernel.org/stable/c/fb61d7b9fb6ef0032de469499a54dab4c7260d0d", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/fb61d7b9fb6ef0032de469499a54dab4c7260d0d" }, { "url": "https://git.kernel.org/stable/c/b180739b45a38b4caa88fe16bb5273072e6613dc", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/b180739b45a38b4caa88fe16bb5273072e6613dc" }, { "url": "https://git.kernel.org/stable/c/f8bd689f37f4198a4c61c4684f591ba639595b97", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/f8bd689f37f4198a4c61c4684f591ba639595b97" }, { "url": "https://git.kernel.org/stable/c/f0c18025693707ec344a70b6887f7450bf4c826b", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/f0c18025693707ec344a70b6887f7450bf4c826b" } ] }, "generator": { "engine": "bippy-c9c4e1df01b2" } }