CVE-2024-56614: linux kernel vulnerability

What is known

In the Linux kernel, the following vulnerability has been resolved: xsk: fix OOB map writes when deleting elements Jordy says: " In the xsk_map_delete_elem function an unsigned integer (map->max_entries) is compared with a user-controlled signed integer (k). Due to implicit type conversion, a large unsigned value for map->max_entries can bypass the intended bounds check: if (k >= map->max_entries) return -EINVAL; This allows k to hold a negative value (between -2147483648 and -2), which is then used as an array index in m->xsk_map[k], which results in an out-of-bounds access. spin_lock_bh(&m->lock); map_entry = &m->xsk_map[k]; // Out-of-bounds map_entry old_xs = unrcu_pointer(xchg(map_entry, NULL)); // Oob write if (old_xs) xsk_map_sock_delete(old_xs, map_entry); spin_unlock_bh(&m->lock); The xchg operation can then be used to cause an out-of-bounds write. Moreover, the invalid map_entry passed to xsk_map_sock_delete can lead to further memory corruption. " It indeed results in following splat: [76612.897343] BUG: unable to handle page fault for address: ffffc8fc2e461108 [76612.904330] #PF: supervisor write access in kernel mode [76612.909639] #PF: error_code(0x0002) - not-present page [76612.914855] PGD 0 P4D 0 [76612.917431] Oops: Oops: 0002 [#1] PREEMPT SMP [76612.921859] CPU: 11 UID: 0 PID: 10318 Comm: a.out Not tainted 6.12.0-rc1+ #470 [76612.929189] Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019 [76612.939781] RIP: 0010:xsk_map_delete_elem+0x2d/0x60 [76612.944738] Code: 00 00 41 54 55 53 48 63 2e 3b 6f 24 73 38 4c 8d a7 f8 00 00 00 48 89 fb 4c 89 e7 e8 2d bf 05 00 48 8d b4 eb 00 01 00 00 31 ff <48> 87 3e 48 85 ff 74 05 e8 16 ff ff ff 4c 89 e7 e8 3e bc 05 00 31 [76612.963774] RSP: 0018:ffffc9002e407df8 EFLAGS: 00010246 [76612.969079] RAX: 0000000000000000 RBX: ffffc9002e461000 RCX: 0000000000000000 [76612.976323] RDX: 0000000000000001 RSI: ffffc8fc2e461108 RDI: 0000000000000000 [76612.983569] RBP: ffffffff80000001 R08: 0000000000000000 R09: 0000000000000007 [76612.990812] R10: ffffc9002e407e18 R11: ffff888108a38858 R12: ffffc9002e4610f8 [76612.998060] R13: ffff888108a38858 R14: 00007ffd1ae0ac78 R15: ffffc9002e4610c0 [76613.005303] FS: 00007f80b6f59740(0000) GS:ffff8897e0ec0000(0000) knlGS:0000000000000000 [76613.013517] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [76613.019349] CR2: ffffc8fc2e461108 CR3: 000000011e3ef001 CR4: 00000000007726f0 [76613.026595] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [76613.033841] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [76613.041086] PKRU: 55555554 [76613.043842] Call Trace: [76613.046331] <TASK> [76613.048468] ? __die+0x20/0x60 [76613.051581] ? page_fault_oops+0x15a/0x450 [76613.055747] ? search_extable+0x22/0x30 [76613.059649] ? search_bpf_extables+0x5f/0x80 [76613.063988] ? exc_page_fault+0xa9/0x140 [76613.067975] ? asm_exc_page_fault+0x22/0x30 [76613.072229] ? xsk_map_delete_elem+0x2d/0x60 [76613.076573] ? xsk_map_delete_elem+0x23/0x60 [76613.080914] __sys_bpf+0x19b7/0x23c0 [76613.084555] __x64_sys_bpf+0x1a/0x20 [76613.088194] do_syscall_64+0x37/0xb0 [76613.091832] entry_SYSCALL_64_after_hwframe+0x4b/0x53 [76613.096962] RIP: 0033:0x7f80b6d1e88d [76613.100592] Code: 5b 41 5c c3 66 0f 1f 84 00 00 00 00 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 8b 0d 73 b5 0f 00 f7 d8 64 89 01 48 [76613.119631] RSP: 002b:00007ffd1ae0ac68 EFLAGS: 00000206 ORIG_RAX: 0000000000000141 [76613.131330] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f80b6d1e88d [76613.142632] RDX: 0000000000000098 RSI: 00007ffd1ae0ad20 RDI: 0000000000000003 [76613.153967] RBP: 00007ffd1ae0adc0 R08: 0000000000000000 R09: 0000000000000000 [76613.166030] R10: 00007f80b6f77040 R11: 0000000000000206 R12: 00007ffd1ae0aed8 [76613.177130] R13: 000055ddf42ce1e9 R14: 000055ddf42d0d98 R15: 00 ---truncated---

Business impact

Successful exploitation of CVE-2024-56614, a high vulnerability (CVSS 7.8) affecting linux kernel, may affect the confidentiality, integrity or availability of the vulnerable environment. The exact impact depends on the installed version, exposed interfaces and deployment configuration.

Recommended administrator action

Confirm whether linux kernel is present and compare installed versions with the vendor advisory and NVD record. Apply the vendor patch or documented mitigation; until remediation is complete, reduce exposure of affected interfaces, review relevant logs and monitor for indicators of exploitation. DataHouse can support version verification, managed patching, network exposure reduction, log review and backup validation for dedicated, cloud and colocated environments.

Sources

• NVD
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