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TI-2021-21857 Aliases CVE-2021-47196GHSA-j2j3-mjcj-v75r

RDMA/core: Set send and receive CQ before forwarding to the driver

Priority LOW 33CWE-416Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 4 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.

Summary

In the Linux kernel, the following vulnerability has been resolved: RDMA/core: Set send and receive CQ before forwarding to the driver Preset both receive and send CQ pointers prior to call to the drivers and overwrite it later again till the mlx4 is going to be changed do not overwrite ibqp properties. This change is needed for mlx5, because in case of QP creation failure, it will go to the path of QP destroy which relies on proper CQ pointers. BUG: KASAN: use-after-free in create_qp.cold+0x164/0x16e [mlx5_ib] Write of size 8 at addr ffff8880064c55c0 by task a.out/246 CPU: 0 PID: 246 Comm: a.out Not tainted 5.15.0+ #291 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack_lvl+0x45/0x59 print_address_description.constprop.0+0x1f/0x140 kasan_report.cold+0x83/0xdf create_qp.cold+0x164/0x16e [mlx5_ib] mlx5_ib_create_qp+0x358/0x28a0 [mlx5_ib] create_qp.part.0+0x45b/0x6a0 [ib_core] ib_create_qp_user+0x97/0x150 [ib_core] ib_uverbs_handler_UVERBS_METHOD_QP_CREATE+0x92c/0x1250 [ib_uverbs] ib_uverbs_cmd_verbs+0x1c38/0x3150 [ib_uverbs] ib_uverbs_ioctl+0x169/0x260 [ib_uverbs] __x64_sys_ioctl+0x866/0x14d0 do_syscall_64+0x3d/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae Allocated by task 246: kasan_save_stack+0x1b/0x40 __kasan_kmalloc+0xa4/0xd0 create_qp.part.0+0x92/0x6a0 [ib_core] ib_create_qp_user+0x97/0x150 [ib_core] ib_uverbs_handler_UVERBS_METHOD_QP_CREATE+0x92c/0x1250 [ib_uverbs] ib_uverbs_cmd_verbs+0x1c38/0x3150 [ib_uverbs] ib_uverbs_ioctl+0x169/0x260 [ib_uverbs] __x64_sys_ioctl+0x866/0x14d0 do_syscall_64+0x3d/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 246: kasan_save_stack+0x1b/0x40 kasan_set_track+0x1c/0x30 kasan_set_free_info+0x20/0x30 __kasan_slab_free+0x10c/0x150 slab_free_freelist_hook+0xb4/0x1b0 kfree+0xe7/0x2a0 create_qp.part.0+0x52b/0x6a0 [ib_core] ib_create_qp_user+0x97/0x150 [ib_core] ib_uverbs_handler_UVERBS_METHOD_QP_CREATE+0x92c/0x1250 [ib_uverbs] ib_uverbs_cmd_verbs+0x1c38/0x3150 [ib_uverbs] ib_uverbs_ioctl+0x169/0x260 [ib_uverbs] __x64_sys_ioctl+0x866/0x14d0 do_syscall_64+0x3d/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00221 12th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.15.5, 5.16Red Hat: 4 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux5.15 and later5.15.5, 5.16Patch availableCNA
  • Linux VendorLinux Affected 5.15 and later Fixed in 5.15.5, 5.16 Patch available CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*5.15 to before 5.15.5VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.16:rc1:*:*:*:*:*:*5.16 rc1VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.15 to before 5.15.5 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:5.16:rc1:*:*:*:*:*:* Versions 5.16 rc1 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 5.15.5, 5.16

Vendor assessments

Red Hat

Red Hat rating: Low. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 8AffectedNo fix yet
Red Hat Enterprise Linux 9AffectedNo fix yet

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-47196
  2. 2026-10-03 Alias added: GHSA-j2j3-mjcj-v75r

References

Patch 2

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
  • TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
See all 15278 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences