CVE-2022-48914
Xen Netfront NULL Pointer Dereference
Description
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
INFO
Published Date :
Aug. 22, 2024, 2:15 a.m.
Last Modified :
Sept. 12, 2024, 1:27 p.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
No
Impact Score :
3.6
Exploitability Score :
1.8
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2022-48914.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2022-48914 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2022-48914 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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Initial Analysis by [email protected]
Sep. 12, 2024
Action Type Old Value New Value Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Changed Reference Type https://git.kernel.org/stable/c/198cdc287769c717dafff5887c6125cb7a373bf3 No Types Assigned https://git.kernel.org/stable/c/198cdc287769c717dafff5887c6125cb7a373bf3 Patch Changed Reference Type https://git.kernel.org/stable/c/47e2f166ed9fe17f24561d6315be2228f6a90209 No Types Assigned https://git.kernel.org/stable/c/47e2f166ed9fe17f24561d6315be2228f6a90209 Patch Changed Reference Type https://git.kernel.org/stable/c/a1753d5c29a6fb9a8966dcf04cb4f3b71e303ae8 No Types Assigned https://git.kernel.org/stable/c/a1753d5c29a6fb9a8966dcf04cb4f3b71e303ae8 Patch Changed Reference Type https://git.kernel.org/stable/c/a63eb1e4a2e1a191a90217871e67fba42fd39255 No Types Assigned https://git.kernel.org/stable/c/a63eb1e4a2e1a191a90217871e67fba42fd39255 Patch Changed Reference Type https://git.kernel.org/stable/c/b40c912624775a21da32d1105e158db5f6d0554a No Types Assigned https://git.kernel.org/stable/c/b40c912624775a21da32d1105e158db5f6d0554a Patch Changed Reference Type https://git.kernel.org/stable/c/dcf4ff7a48e7598e6b10126cc02177abb8ae4f3f No Types Assigned https://git.kernel.org/stable/c/dcf4ff7a48e7598e6b10126cc02177abb8ae4f3f Patch Added CWE NIST CWE-476 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.19.226 up to (excluding) 4.19.233 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.4.174 up to (excluding) 5.4.183 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.10.94 up to (excluding) 5.10.104 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.15.17 up to (excluding) 5.15.27 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16.3 up to (excluding) 5.16.13 -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 22, 2024
Action Type Old Value New Value Added Description 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 Added Reference kernel.org https://git.kernel.org/stable/c/198cdc287769c717dafff5887c6125cb7a373bf3 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/b40c912624775a21da32d1105e158db5f6d0554a [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/a1753d5c29a6fb9a8966dcf04cb4f3b71e303ae8 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/a63eb1e4a2e1a191a90217871e67fba42fd39255 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/47e2f166ed9fe17f24561d6315be2228f6a90209 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/dcf4ff7a48e7598e6b10126cc02177abb8ae4f3f [No types assigned]
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2022-48914 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2022-48914
weaknesses.