CVE-2021-47615 Affecting kernel-rt-trace-devel package, versions *
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Test your applications- Snyk ID SNYK-CENTOS7-KERNELRTTRACEDEVEL-7295562
- published 20 Jun 2024
- disclosed 19 Jun 2024
How to fix?
There is no fixed version for Centos:7 kernel-rt-trace-devel.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel-rt-trace-devel package and not the kernel-rt-trace-devel package as distributed by Centos.
See How to fix? for Centos:7 relevant fixed versions and status.
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.