Bug 2402222 (CVE-2022-50543)

Summary: CVE-2022-50543 kernel: RDMA/rxe: Fix mr->map double free
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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OS: Linux   
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A double-free vulnerability was found in the Linux kernel RDMA RXE (soft-RoCE) driver's memory region handling. A local user with access to RDMA userspace verbs can register a memory region with parameters that cause initialization to fail, triggering error handling code that frees the mr->map structure twice, which leads to memory corruption and can result in denial of service via kernel crash or potentially privilege escalation through heap manipulation.
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Description OSIDB Bzimport 2025-10-07 16:03:48 UTC
In the Linux kernel, the following vulnerability has been resolved:

RDMA/rxe: Fix mr->map double free

rxe_mr_cleanup() which tries to free mr->map again will be called when
rxe_mr_init_user() fails:

   CPU: 0 PID: 4917 Comm: rdma_flush_serv Kdump: loaded Not tainted 6.1.0-rc1-roce-flush+ #25
   Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
   Call Trace:
    <TASK>
    dump_stack_lvl+0x45/0x5d
    panic+0x19e/0x349
    end_report.part.0+0x54/0x7c
    kasan_report.cold+0xa/0xf
    rxe_mr_cleanup+0x9d/0xf0 [rdma_rxe]
    __rxe_cleanup+0x10a/0x1e0 [rdma_rxe]
    rxe_reg_user_mr+0xb7/0xd0 [rdma_rxe]
    ib_uverbs_reg_mr+0x26a/0x480 [ib_uverbs]
    ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0x1a2/0x250 [ib_uverbs]
    ib_uverbs_cmd_verbs+0x1397/0x15a0 [ib_uverbs]

This issue was firstly exposed since commit b18c7da63fcb ("RDMA/rxe: Fix
memory leak in error path code") and then we fixed it in commit
8ff5f5d9d8cf ("RDMA/rxe: Prevent double freeing rxe_map_set()") but this
fix was reverted together at last by commit 1e75550648da (Revert
"RDMA/rxe: Create duplicate mapping tables for FMRs")

Simply let rxe_mr_cleanup() always handle freeing the mr->map once it is
successfully allocated.

Comment 6 errata-xmlrpc 2025-12-08 02:50:54 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2025:22800 https://access.redhat.com/errata/RHSA-2025:22800

Comment 7 errata-xmlrpc 2025-12-08 03:07:25 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2025:22801 https://access.redhat.com/errata/RHSA-2025:22801