# CVE-2021-47078: linux: In the Linux kernel, the following vulnerability has been resolved:  RDMA/rxe: Clear all QP fields if creation failed...

CVE-2021-47078 is fixed in linux on 1 platform, first by DEBIAN-CVE-2021-47078, released March 1, 2024. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2021-47078
- Priority: High
- CVSS: 7.8 (high)
- EPSS: 0.0028
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Mar 1, 2024

## Description

In the Linux kernel, the following vulnerability has been resolved:  RDMA/rxe: Clear all QP fields if creation failed  rxe_qp_do_cleanup() relies on valid pointer values in QP for the properly created ones, but in case rxe_qp_from_init() failed it was filled with garbage and caused tot the following error.    refcount_t: underflow; use-after-free.   WARNING: CPU: 1 PID: 12560 at lib/refcount.c:28 refcount_warn_saturate+0x1d1/0x1e0 lib/refcount.c:28   Modules linked in:   CPU: 1 PID: 12560 Comm: syz-executor.4 Not tainted 5.12.0-syzkaller #0   Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011   RIP: 0010:refcount_warn_saturate+0x1d1/0x1e0 lib/refcount.c:28   Code: e9 db fe ff ff 48 89 df e8 2c c2 ea fd e9 8a fe ff ff e8 72 6a a7 fd 48 c7 c7 e0 b2 c1 89 c6 05 dc 3a e6 09 01 e8 ee 74 fb 04 <0f> 0b e9 af fe ff ff 0f 1f 84 00 00 00 00 00 41 56 41 55 41 54 55   RSP: 0018:ffffc900097ceba8 EFLAGS: 00010286   RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000   RDX: 0000000000040000 RSI: ffffffff815bb075 RDI: fffff520012f9d67   RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000   R10: ffffffff815b4eae R11: 0000000000000000 R12: ffff8880322a4800   R13: ffff8880322a4940 R14: ffff888033044e00 R15: 0000000000000000   FS:  00007f6eb2be3700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033   CR2: 00007fdbe5d41000 CR3: 000000001d181000 CR4: 00000000001506e0   DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000   DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400   Call Trace:    __refcount_sub_and_test include/linux/refcount.h:283 [inline]    __refcount_dec_and_test include/linux/refcount.h:315 [inline]    refcount_dec_and_test include/linux/refcount.h:333 [inline]    kref_put include/linux/kref.h:64 [inline]    rxe_qp_do_cleanup+0x96f/0xaf0 drivers/infiniband/sw/rxe/rxe_qp.c:805    execute_in_process_context+0x37/0x150 kernel/workqueue.c:3327    rxe_elem_release+0x9f/0x180 drivers/infiniband/sw/rxe/rxe_pool.c:391    kref_put include/linux/kref.h:65 [inline]    rxe_create_qp+0x2cd/0x310 drivers/infiniband/sw/rxe/rxe_verbs.c:425    _ib_create_qp drivers/infiniband/core/core_priv.h:331 [inline]    ib_create_named_qp+0x2ad/0x1370 drivers/infiniband/core/verbs.c:1231    ib_create_qp include/rdma/ib_verbs.h:3644 [inline]    create_mad_qp+0x177/0x2d0 drivers/infiniband/core/mad.c:2920    ib_mad_port_open drivers/infiniband/core/mad.c:3001 [inline]    ib_mad_init_device+0xd6f/0x1400 drivers/infiniband/core/mad.c:3092    add_client_context+0x405/0x5e0 drivers/infiniband/core/device.c:717    enable_device_and_get+0x1cd/0x3b0 drivers/infiniband/core/device.c:1331    ib_register_device drivers/infiniband/core/device.c:1413 [inline]    ib_register_device+0x7c7/0xa50 drivers/infiniband/core/device.c:1365    rxe_register_device+0x3d5/0x4a0 drivers/infiniband/sw/rxe/rxe_verbs.c:1147    rxe_add+0x12fe/0x16d0 drivers/infiniband/sw/rxe/rxe.c:247    rxe_net_add+0x8c/0xe0 drivers/infiniband/sw/rxe/rxe_net.c:503    rxe_newlink drivers/infiniband/sw/rxe/rxe.c:269 [inline]    rxe_newlink+0xb7/0xe0 drivers/infiniband/sw/rxe/rxe.c:250    nldev_newlink+0x30e/0x550 drivers/infiniband/core/nldev.c:1555    rdma_nl_rcv_msg+0x36d/0x690 drivers/infiniband/core/netlink.c:195    rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline]    rdma_nl_rcv+0x2ee/0x430 drivers/infiniband/core/netlink.c:259    netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]    netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1338    netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1927    sock_sendmsg_nosec net/socket.c:654 [inline]    sock_sendmsg+0xcf/0x120 net/socket.c:674    ____sys_sendmsg+0x6e8/0x810 net/socket.c:2350    ___sys_sendmsg+0xf3/0x170 net/socket.c:2404    __sys_sendmsg+0xe5/0x1b0 net/socket.c:2433    do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47    entry_SYSCALL_64_after_hwframe+0 ---truncated---

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 5.10.40-1 | [DEBIAN-CVE-2021-47078](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47078.md) | Mar 1, 2024 |
| Linux | linux Debian 13.5 (trixie) | 5.10.40-1 | [DEBIAN-CVE-2021-47078](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47078.md) | Mar 1, 2024 |
| Linux | linux Debian 14 | 5.10.40-1 | [DEBIAN-CVE-2021-47078](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47078.md) | Mar 1, 2024 |

---

Data as of 2026-11-09T07:25:28Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.