CVE-2021-47562

Medium

In the Linux kernel, the following vulnerability has been resolved: ice: fix vsi->txq_map sizing The approach of having XDP queue per CPU regardless of user's setting exposed a hidden bug that could occur in case when Rx queue count differ from Tx queue count. Currently vsi->txq_map's size is equal to the doubled vsi->alloc_txq, which is not correct due to the fact that XDP rings were previously based on the Rx queue count. Below splat can be seen when ethtool -L is used and XDP rings are configured: [ 682.875339] BUG: kernel NULL pointer dereference, address: 000000000000000f [ 682.883403] #PF: supervisor read access in kernel mode [ 682.889345] #PF: error_code(0x0000) - not-present page [ 682.895289] PGD 0 P4D 0 [ 682.898218] Oops: 0000 [#1] PREEMPT SMP PTI [ 682.903055] CPU: 42 PID: 2878 Comm: ethtool Tainted: G OE 5.15.0-rc5+ #1 [ 682.912214] Hardware name: Intel Corp. GRANTLEY/GRANTLEY, BIOS GRRFCRB1.86B.0276.D07.1605190235 05/19/2016 [ 682.923380] RIP: 0010:devres_remove+0x44/0x130 [ 682.928527] Code: 49 89 f4 55 48 89 fd 4c 89 ff 53 48 83 ec 10 e8 92 b9 49 00 48 8b 9d a8 02 00 00 48 8d 8d a0 02 00 00 49 89 c2 48 39 cb 74 0f <4c> 3b 63 10 74 25 48 8b 5b 08 48 39 cb 75 f1 4c 89 ff 4c 89 d6 e8 [ 682.950237] RSP: 0018:ffffc90006a679f0 EFLAGS: 00010002 [ 682.956285] RAX: 0000000000000286 RBX: ffffffffffffffff RCX: ffff88908343a370 [ 682.964538] RDX: 0000000000000001 RSI: ffffffff81690d60 RDI: 0000000000000000 [ 682.972789] RBP: ffff88908343a0d0 R08: 0000000000000000 R09: 0000000000000000 [ 682.981040] R10: 0000000000000286 R11: 3fffffffffffffff R12: ffffffff81690d60 [ 682.989282] R13: ffffffff81690a00 R14: ffff8890819807a8 R15: ffff88908343a36c [ 682.997535] FS: 00007f08c7bfa740(0000) GS:ffff88a03fd00000(0000) knlGS:0000000000000000 [ 683.006910] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 683.013557] CR2: 000000000000000f CR3: 0000001080a66003 CR4: 00000000003706e0 [ 683.021819] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 683.030075] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 683.038336] Call Trace: [ 683.041167] devm_kfree+0x33/0x50 [ 683.045004] ice_vsi_free_arrays+0x5e/0xc0 [ice] [ 683.050380] ice_vsi_rebuild+0x4c8/0x750 [ice] [ 683.055543] ice_vsi_recfg_qs+0x9a/0x110 [ice] [ 683.060697] ice_set_channels+0x14f/0x290 [ice] [ 683.065962] ethnl_set_channels+0x333/0x3f0 [ 683.070807] genl_family_rcv_msg_doit+0xea/0x150 [ 683.076152] genl_rcv_msg+0xde/0x1d0 [ 683.080289] ? channels_prepare_data+0x60/0x60 [ 683.085432] ? genl_get_cmd+0xd0/0xd0 [ 683.089667] netlink_rcv_skb+0x50/0xf0 [ 683.094006] genl_rcv+0x24/0x40 [ 683.097638] netlink_unicast+0x239/0x340 [ 683.102177] netlink_sendmsg+0x22e/0x470 [ 683.106717] sock_sendmsg+0x5e/0x60 [ 683.110756] __sys_sendto+0xee/0x150 [ 683.114894] ? handle_mm_fault+0xd0/0x2a0 [ 683.119535] ? do_user_addr_fault+0x1f3/0x690 [ 683.134173] __x64_sys_sendto+0x25/0x30 [ 683.148231] do_syscall_64+0x3b/0xc0 [ 683.161992] entry_SYSCALL_64_after_hwframe+0x44/0xae Fix this by taking into account the value that num_possible_cpus() yields in addition to vsi->alloc_txq instead of doubling the latter.

Package Linux Kernel
Published 2024-05-24
Last modified 2025-01-06
CVSS version 3.1
Patch available
Awaiting data

CVSS 3.1 score

5.5

out of 10
Medium
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness type

CWE-476

CVE-2021-47562 is a NULL Pointer Dereference vulnerability

What is NULL Pointer Dereference?

The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. Learn more on MITRE CWE

References

The following references provide additional information about CVE-2021-47562 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Frequently asked questions

  • What is CVE-2021-47562?

    CVE-2021-47562 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a NULL Pointer Dereference flaw (CWE-476) . CVE-2021-47562 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2021-47562?

    CVE-2021-47562 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2021-47562?

    No patch is currently available for CVE-2021-47562. Monitor the NIST NVD and your Linux distribution's security advisories for updates.

  • Is CVE-2021-47562 actively exploited?

    No — CVE-2021-47562 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is NULL Pointer Dereference (CWE-476)?

    The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. View CWE-476 on MITRE CWE →

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