{"cve":"CVE-2024-26733","nvd":{"published":"2024-04-03T17:15:51.040","modified":"2026-06-17T07:18:12.250","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\narp: Prevent overflow in arp_req_get().\n\nsyzkaller reported an overflown write in arp_req_get(). [0]\n\nWhen ioctl(SIOCGARP) is issued, arp_req_get() looks up an neighbour\nentry and copies neigh->ha to struct arpreq.arp_ha.sa_data.\n\nThe arp_ha here is struct sockaddr, not struct sockaddr_storage, so\nthe sa_data buffer is just 14 bytes.\n\nIn the splat below, 2 bytes are overflown to the next int field,\narp_flags.  We initialise the field just after the memcpy(), so it's\nnot a problem.\n\nHowever, when dev->addr_len is greater than 22 (e.g. MAX_ADDR_LEN),\narp_netmask is overwritten, which could be set as htonl(0xFFFFFFFFUL)\nin arp_ioctl() before calling arp_req_get().\n\nTo avoid the overflow, let's limit the max length of memcpy().\n\nNote that commit b5f0de6df6dc (\"net: dev: Convert sa_data to flexible\narray in struct sockaddr\") just silenced syzkaller.\n\n[0]:\nmemcpy: detected field-spanning write (size 16) of single field \"r->arp_ha.sa_data\" at net/ipv4/arp.c:1128 (size 14)\nWARNING: CPU: 0 PID: 144638 at net/ipv4/arp.c:1128 arp_req_get+0x411/0x4a0 net/ipv4/arp.c:1128\nModules linked in:\nCPU: 0 PID: 144638 Comm: syz-executor.4 Not tainted 6.1.74 #31\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-debian-1.16.0-5 04/01/2014\nRIP: 0010:arp_req_get+0x411/0x4a0 net/ipv4/arp.c:1128\nCode: fd ff ff e8 41 42 de fb b9 0e 00 00 00 4c 89 fe 48 c7 c2 20 6d ab 87 48 c7 c7 80 6d ab 87 c6 05 25 af 72 04 01 e8 5f 8d ad fb <0f> 0b e9 6c fd ff ff e8 13 42 de fb be 03 00 00 00 4c 89 e7 e8 a6\nRSP: 0018:ffffc900050b7998 EFLAGS: 00010286\nRAX: 0000000000000000 RBX: ffff88803a815000 RCX: 0000000000000000\nRDX: 0000000000000000 RSI: ffffffff8641a44a RDI: 0000000000000001\nRBP: ffffc900050b7a98 R08: 0000000000000001 R09: 0000000000000000\nR10: 0000000000000000 R11: 203a7970636d656d R12: ffff888039c54000\nR13: 1ffff92000a16f37 R14: ffff88803a815084 R15: 0000000000000010\nFS:  00007f172bf306c0(0000) GS:ffff88805aa00000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007f172b3569f0 CR3: 0000000057f12005 CR4: 0000000000770ef0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nPKRU: 55555554\nCall Trace:\n <TASK>\n arp_ioctl+0x33f/0x4b0 net/ipv4/arp.c:1261\n inet_ioctl+0x314/0x3a0 net/ipv4/af_inet.c:981\n sock_do_ioctl+0xdf/0x260 net/socket.c:1204\n sock_ioctl+0x3ef/0x650 net/socket.c:1321\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:870 [inline]\n __se_sys_ioctl fs/ioctl.c:856 [inline]\n __x64_sys_ioctl+0x18e/0x220 fs/ioctl.c:856\n do_syscall_x64 arch/x86/entry/common.c:51 [inline]\n do_syscall_64+0x37/0x90 arch/x86/entry/common.c:81\n entry_SYSCALL_64_after_hwframe+0x64/0xce\nRIP: 0033:0x7f172b262b8d\nCode: 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48\nRSP: 002b:00007f172bf300b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010\nRAX: ffffffffffffffda RBX: 00007f172b3abf80 RCX: 00007f172b262b8d\nRDX: 0000000020000000 RSI: 0000000000008954 RDI: 0000000000000003\nRBP: 00007f172b2d3493 R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000\nR13: 000000000000000b R14: 00007f172b3abf80 R15: 00007f172bf10000\n </TASK>","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-787"],"references":["https://git.kernel.org/stable/c/3ab0d6f8289ba8402ca95a9fc61a34909d5e1f3a","https://git.kernel.org/stable/c/97eaa2955db4120ce6ec2ef123e860bc32232c50","https://git.kernel.org/stable/c/a3f2c083cb575d80a7627baf3339e78fedccbb91","https://git.kernel.org/stable/c/a7d6027790acea24446ddd6632d394096c0f4667","https://git.kernel.org/stable/c/dbc9b22d0ed319b4e29034ce0a3fe32a3ee2c587"],"products":["debian:debian_linux","linux:linux_kernel","netapp:8200_firmware","netapp:8300_firmware","netapp:8700_firmware","netapp:9000_firmware","netapp:9500_firmware","netapp:a150_firmware","netapp:a1k_firmware","netapp:a220_firmware","netapp:a300_firmware","netapp:a320_firmware","netapp:a400_firmware","netapp:a700_firmware","netapp:a700s_firmware","netapp:a70_firmware","netapp:a800_firmware","netapp:a900_firmware","netapp:a90_firmware","netapp:c190_firmware","netapp:c400_firmware","netapp:c800_firmware","netapp:e-series_santricity_os_controller","netapp:fas2720_firmware","netapp:fas2750_firmware","netapp:fas2820_firmware","netapp:h610c_firmware","netapp:h610s_firmware","netapp:h615c_firmware"],"source":"nvd","synced_at":"2026-10-19T21:47:51.568503435+00:00"},"epss":{"cve":"CVE-2024-26733","score":0.00256,"percentile":0.1726,"date":"2026-10-31"},"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."]}