• CVE-2021-47615

发布时间: 2024年6月27日

修改时间: 2024年11月30日

概要

In the Linux kernel, the following vulnerability has been resolved: RDMA/mlx5: Fix releasing unallocated memory in dereg MR flow For the case of IB_MR_TYPE_DM the mr does doesn't have a umem, even though it is a user MR. This causes function mlx5_free_priv_descs() to think that it is a kernel MR, leading to wrongly accessing mr->descs that will get wrong values in the union which leads to attempt to release resources that were not allocated in the first place. For example: DMA-API: mlx5_core 0000:08:00.1: device driver tries to free DMA memory it has not allocated [device address=0x0000000000000000] [size=0 bytes] WARNING: CPU: 8 PID: 1021 at kernel/dma/debug.c:961 check_unmap+0x54f/0x8b0 RIP: 0010:check_unmap+0x54f/0x8b0 Call Trace: debug_dma_unmap_page+0x57/0x60 mlx5_free_priv_descs+0x57/0x70 [mlx5_ib] mlx5_ib_dereg_mr+0x1fb/0x3d0 [mlx5_ib] ib_dereg_mr_user+0x60/0x140 [ib_core] uverbs_destroy_uobject+0x59/0x210 [ib_uverbs] uobj_destroy+0x3f/0x80 [ib_uverbs] ib_uverbs_cmd_verbs+0x435/0xd10 [ib_uverbs] ? uverbs_finalize_object+0x50/0x50 [ib_uverbs] ? lock_acquire+0xc4/0x2e0 ? lock_acquired+0x12/0x380 ? lock_acquire+0xc4/0x2e0 ? lock_acquire+0xc4/0x2e0 ? ib_uverbs_ioctl+0x7c/0x140 [ib_uverbs] ? lock_release+0x28a/0x400 ib_uverbs_ioctl+0xc0/0x140 [ib_uverbs] ? ib_uverbs_ioctl+0x7c/0x140 [ib_uverbs] __x64_sys_ioctl+0x7f/0xb0 do_syscall_64+0x38/0x90 Fix it by reorganizing the dereg flow and mlx5_ib_mr structure: - Move the ib_umem field into the user MRs structure in the union as it's applicable only there. - Function mlx5_ib_dereg_mr() will now call mlx5_free_priv_descs() only in case there isn't udata, which indicates that this isn't a user MR.

CVSS v3 指标

NVD openEuler
Confidentiality None None
Attack Vector Local Local
CVSS评分 5.5 3.4
Attack Complexity Low High
Privileges Required Low High
Scope Unchanged Unchanged
Integrity None None
User Interaction None None
Availability High None

安全公告

公告名 概要 发布时间
KylinSec-SA-2024-2909 In the Linux kernel, the following vulnerability has been resolved: RDMA/mlx5: Fix releasing unallocated memory in dereg MR flow For the case of IB_MR_TYPE_DM the mr does doesn't have a umem, even though it is a user MR. This causes function mlx5_free_priv_descs() to think that it is a kernel MR, leading to wrongly accessing mr->descs that will get wrong values in the union which leads to attempt to release resources that were not allocated in the first place. For example: DMA-API: mlx5_core 0000:08:00.1: device driver tries to free DMA memory it has not allocated [device address=0x0000000000000000] [size=0 bytes] WARNING: CPU: 8 PID: 1021 at kernel/dma/debug.c:961 check_unmap+0x54f/0x8b0 RIP: 0010:check_unmap+0x54f/0x8b0 Call Trace: debug_dma_unmap_page+0x57/0x60 mlx5_free_priv_descs+0x57/0x70 [mlx5_ib] mlx5_ib_dereg_mr+0x1fb/0x3d0 [mlx5_ib] ib_dereg_mr_user+0x60/0x140 [ib_core] uverbs_destroy_uobject+0x59/0x210 [ib_uverbs] uobj_destroy+0x3f/0x80 [ib_uverbs] ib_uverbs_cmd_verbs+0x435/0xd10 [ib_uverbs] ? uverbs_finalize_object+0x50/0x50 [ib_uverbs] ? lock_acquire+0xc4/0x2e0 ? lock_acquired+0x12/0x380 ? lock_acquire+0xc4/0x2e0 ? lock_acquire+0xc4/0x2e0 ? ib_uverbs_ioctl+0x7c/0x140 [ib_uverbs] ? lock_release+0x28a/0x400 ib_uverbs_ioctl+0xc0/0x140 [ib_uverbs] ? ib_uverbs_ioctl+0x7c/0x140 [ib_uverbs] __x64_sys_ioctl+0x7f/0xb0 do_syscall_64+0x38/0x90 Fix it by reorganizing the dereg flow and mlx5_ib_mr structure: - Move the ib_umem field into the user MRs structure in the union as it's applicable only there. - Function mlx5_ib_dereg_mr() will now call mlx5_free_priv_descs() only in case there isn't udata, which indicates that this isn't a user MR. 2024年6月27日

影响产品

产品 状态
KY3.4-5A kernel Unaffected
KY3.5.2 kernel Unaffected
V6 kernel Unaffected