ghsa-xqrq-q336-f78g
Vulnerability from github
Published
2024-04-03 18:30
Modified
2024-06-26 00:31
Details

In the Linux kernel, the following vulnerability has been resolved:

arp: Prevent overflow in arp_req_get().

syzkaller reported an overflown write in arp_req_get(). [0]

When ioctl(SIOCGARP) is issued, arp_req_get() looks up an neighbour entry and copies neigh->ha to struct arpreq.arp_ha.sa_data.

The arp_ha here is struct sockaddr, not struct sockaddr_storage, so the sa_data buffer is just 14 bytes.

In the splat below, 2 bytes are overflown to the next int field, arp_flags. We initialise the field just after the memcpy(), so it's not a problem.

However, when dev->addr_len is greater than 22 (e.g. MAX_ADDR_LEN), arp_netmask is overwritten, which could be set as htonl(0xFFFFFFFFUL) in arp_ioctl() before calling arp_req_get().

To avoid the overflow, let's limit the max length of memcpy().

Note that commit b5f0de6df6dc ("net: dev: Convert sa_data to flexible array in struct sockaddr") just silenced syzkaller.

[0]: memcpy: detected field-spanning write (size 16) of single field "r->arp_ha.sa_data" at net/ipv4/arp.c:1128 (size 14) WARNING: CPU: 0 PID: 144638 at net/ipv4/arp.c:1128 arp_req_get+0x411/0x4a0 net/ipv4/arp.c:1128 Modules linked in: CPU: 0 PID: 144638 Comm: syz-executor.4 Not tainted 6.1.74 #31 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-debian-1.16.0-5 04/01/2014 RIP: 0010:arp_req_get+0x411/0x4a0 net/ipv4/arp.c:1128 Code: 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 RSP: 0018:ffffc900050b7998 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff88803a815000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8641a44a RDI: 0000000000000001 RBP: ffffc900050b7a98 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 203a7970636d656d R12: ffff888039c54000 R13: 1ffff92000a16f37 R14: ffff88803a815084 R15: 0000000000000010 FS: 00007f172bf306c0(0000) GS:ffff88805aa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f172b3569f0 CR3: 0000000057f12005 CR4: 0000000000770ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: arp_ioctl+0x33f/0x4b0 net/ipv4/arp.c:1261 inet_ioctl+0x314/0x3a0 net/ipv4/af_inet.c:981 sock_do_ioctl+0xdf/0x260 net/socket.c:1204 sock_ioctl+0x3ef/0x650 net/socket.c:1321 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x18e/0x220 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x37/0x90 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x64/0xce RIP: 0033:0x7f172b262b8d Code: 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 RSP: 002b:00007f172bf300b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f172b3abf80 RCX: 00007f172b262b8d RDX: 0000000020000000 RSI: 0000000000008954 RDI: 0000000000000003 RBP: 00007f172b2d3493 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f172b3abf80 R15: 00007f172bf10000

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{
  "affected": [],
  "aliases": [
    "CVE-2024-26733"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-04-03T17:15:51Z",
    "severity": null
  },
  "details": "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-\u003eha 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\u0027s\nnot a problem.\n\nHowever, when dev-\u003eaddr_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\u0027s 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-\u003earp_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 \u003c0f\u003e 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 \u003cTASK\u003e\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 \u003c48\u003e 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 \u003c/TASK\u003e",
  "id": "GHSA-xqrq-q336-f78g",
  "modified": "2024-06-26T00:31:36Z",
  "published": "2024-04-03T18:30:41Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-26733"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3ab0d6f8289ba8402ca95a9fc61a34909d5e1f3a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/97eaa2955db4120ce6ec2ef123e860bc32232c50"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a3f2c083cb575d80a7627baf3339e78fedccbb91"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a7d6027790acea24446ddd6632d394096c0f4667"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/dbc9b22d0ed319b4e29034ce0a3fe32a3ee2c587"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f119f2325ba70cbfdec701000dcad4d88805d5b0"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}


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