CVE-2022-48914

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2022-48914
In the Linux kernel, the following vulnerability has been resolved: xen/netfront: destroy queues before real_num_tx_queues is zeroed xennet_destroy_queues() relies on info->netdev->real_num_tx_queues to delete queues. Since d7dac083414eb5bb99a6d2ed53dc2c1b405224e5 ("net-sysfs: update the queue counts in the unregistration path"), unregister_netdev() indirectly sets real_num_tx_queues to 0. Those two facts together means, that xennet_destroy_queues() called from xennet_remove() cannot do its job, because it's called after unregister_netdev(). This results in kfree-ing queues that are still linked in napi, which ultimately crashes: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 1 PID: 52 Comm: xenwatch Tainted: G W 5.16.10-1.32.fc32.qubes.x86_64+ #226 RIP: 0010:free_netdev+0xa3/0x1a0 Code: ff 48 89 df e8 2e e9 00 00 48 8b 43 50 48 8b 08 48 8d b8 a0 fe ff ff 48 8d a9 a0 fe ff ff 49 39 c4 75 26 eb 47 e8 ed c1 66 ff <48> 8b 85 60 01 00 00 48 8d 95 60 01 00 00 48 89 ef 48 2d 60 01 00 RSP: 0000:ffffc90000bcfd00 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff88800edad000 RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffffc90000bcfc30 RDI: 00000000ffffffff RBP: fffffffffffffea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88800edad050 R13: ffff8880065f8f88 R14: 0000000000000000 R15: ffff8880066c6680 FS: 0000000000000000(0000) GS:ffff8880f3300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000000e998c006 CR4: 00000000003706e0 Call Trace: <TASK> xennet_remove+0x13d/0x300 [xen_netfront] xenbus_dev_remove+0x6d/0xf0 __device_release_driver+0x17a/0x240 device_release_driver+0x24/0x30 bus_remove_device+0xd8/0x140 device_del+0x18b/0x410 ? _raw_spin_unlock+0x16/0x30 ? klist_iter_exit+0x14/0x20 ? xenbus_dev_request_and_reply+0x80/0x80 device_unregister+0x13/0x60 xenbus_dev_changed+0x18e/0x1f0 xenwatch_thread+0xc0/0x1a0 ? do_wait_intr_irq+0xa0/0xa0 kthread+0x16b/0x190 ? set_kthread_struct+0x40/0x40 ret_from_fork+0x22/0x30 </TASK> Fix this by calling xennet_destroy_queues() from xennet_uninit(), when real_num_tx_queues is still available. This ensures that queues are destroyed when real_num_tx_queues is set to 0, regardless of how unregister_netdev() was called. Originally reported at https://github.com/QubesOS/qubes-issues/issues/7257

5.5 /10

CVSS v3 : MEDIUM

V3 Legend

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://git.kernel.org/stable/c/198cdc287769c717dafff5887c6125cb7a373bf3 Patch
https://git.kernel.org/stable/c/47e2f166ed9fe17f24561d6315be2228f6a90209 Patch
https://git.kernel.org/stable/c/a1753d5c29a6fb9a8966dcf04cb4f3b71e303ae8 Patch
https://git.kernel.org/stable/c/a63eb1e4a2e1a191a90217871e67fba42fd39255 Patch
https://git.kernel.org/stable/c/b40c912624775a21da32d1105e158db5f6d0554a Patch
https://git.kernel.org/stable/c/dcf4ff7a48e7598e6b10126cc02177abb8ae4f3f Patch
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
History

12 Sep 2024, 13:27

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 5.5
First Time Linux linux Kernel
Linux
References () https://git.kernel.org/stable/c/198cdc287769c717dafff5887c6125cb7a373bf3 - () https://git.kernel.org/stable/c/198cdc287769c717dafff5887c6125cb7a373bf3 - Patch
References () https://git.kernel.org/stable/c/47e2f166ed9fe17f24561d6315be2228f6a90209 - () https://git.kernel.org/stable/c/47e2f166ed9fe17f24561d6315be2228f6a90209 - Patch
References () https://git.kernel.org/stable/c/a1753d5c29a6fb9a8966dcf04cb4f3b71e303ae8 - () https://git.kernel.org/stable/c/a1753d5c29a6fb9a8966dcf04cb4f3b71e303ae8 - Patch
References () https://git.kernel.org/stable/c/a63eb1e4a2e1a191a90217871e67fba42fd39255 - () https://git.kernel.org/stable/c/a63eb1e4a2e1a191a90217871e67fba42fd39255 - Patch
References () https://git.kernel.org/stable/c/b40c912624775a21da32d1105e158db5f6d0554a - () https://git.kernel.org/stable/c/b40c912624775a21da32d1105e158db5f6d0554a - Patch
References () https://git.kernel.org/stable/c/dcf4ff7a48e7598e6b10126cc02177abb8ae4f3f - () https://git.kernel.org/stable/c/dcf4ff7a48e7598e6b10126cc02177abb8ae4f3f - Patch
CWE CWE-476
CPE cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

22 Aug 2024, 12:48

Type Values Removed Values Added
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: xen/netfront: destruye colas antes de que real_num_tx_queues se ponga a cero xennet_destroy_queues() se basa en info-&gt;netdev-&gt;real_num_tx_queues para eliminar colas. Dado que d7dac083414eb5bb99a6d2ed53dc2c1b405224e5 ("net-sysfs: actualice los recuentos de colas en la ruta de cancelación de registro"), unregister_netdev() establece indirectamente real_num_tx_queues en 0. Esos dos hechos juntos significan que xennet_destroy_queues() llamado desde xennet_remove() no puede hacer su trabajo, porque s llamado después de unregister_netdev(). Esto da como resultado colas kfree-ing que todavía están vinculadas en napi, lo que finalmente falla: ERROR: desreferencia del puntero NULL del kernel, dirección: 0000000000000000 #PF: acceso de lectura del supervisor en modo kernel #PF: código_error(0x0000) - PGD de página no presente 0 P4D 0 Ups: 0000 [#1] PREEMPT SMP PTI CPU: 1 PID: 52 Comm: xenwatch Tainted: GW 5.16.10-1.32.fc32.qubes.x86_64+ #226 RIP: 0010:free_netdev+0xa3/0x1a0 Código: ff 48 89 df e8 2e e9 00 00 48 8b 43 50 48 8b 08 48 8d b8 a0 fe ff ff 48 8d a9 a0 fe ff ff 49 39 c4 75 26 eb 47 e8 ed c1 66 ff &lt;48&gt; 8b 85 60 01 00 0 48 8d 95 60 01 00 00 48 89 ef 48 2d 60 01 00 RSP: 0000:ffffc90000bcfd00 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff88800edad000 RCX: 0000000000000 RDX: 0000000000000001 RSI: ffffc90000bcfc30 RDI: 00000000ffffffff RBP: fffffffffffffea0 R08: 00000000000000000 R09: 00000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88800edad050 R13: ffff8880065f8f88 R14: 00000000000000000 R15: ffff8880066c6680 FS: 00000000000000(0000) GS:ffff8880f3300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: CR3: 00000000e998c006 CR4: 00000000003706e0 Seguimiento de llamadas: xennet_remove+0x13d/0x300 [xen_netfront] xenbus_dev_remove+0x6d/0xf0 __device_release_driver+0x17a/0x240 device_release_driver+0x24/ 0x30 bus_remove_device+0xd8/0x140 dispositivo_del+0x18b/0x410? _raw_spin_unlock+0x16/0x30? klist_iter_exit+0x14/0x20? xenbus_dev_request_and_reply+0x80/0x80 dispositivo_unregister+0x13/0x60 xenbus_dev_changed+0x18e/0x1f0 xenwatch_thread+0xc0/0x1a0 ? do_wait_intr_irq+0xa0/0xa0 kthread+0x16b/0x190 ? set_kthread_struct+0x40/0x40 ret_from_fork+0x22/0x30 Solucione este problema llamando a xennet_destroy_queues() desde xennet_uninit(), cuando real_num_tx_queues todavía esté disponible. Esto garantiza que las colas se destruyan cuando real_num_tx_queues se establece en 0, independientemente de cómo se llamó a unregister_netdev(). Reportado originalmente en https://github.com/QubesOS/qubes-issues/issues/7257

22 Aug 2024, 02:15

Type Values Removed Values Added
New CVE
Information

Published : 2024-08-22 02:15

Updated : 2024-09-12 13:27

NVD link : CVE-2022-48914

Mitre link : CVE-2022-48914

CVE.ORG link : CVE-2022-48914

JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-476

NULL Pointer Dereference