NULL Pointer Dereference Affecting perf package, versions *
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-CENTOS6-PERF-17493715
- published25 Jun 2026
- disclosed24 Jun 2026
Introduced: 24 Jun 2026
NewCVE-2026-52939 (opens in a new tab)How to fix?
There is no fixed version for Centos:6 perf.
NVD Description
Note: Versions mentioned in the description apply only to the upstream perf package and not the perf package as distributed by Centos.
See How to fix? for Centos:6 relevant fixed versions and status.
In the Linux kernel, the following vulnerability has been resolved:
net/rds: fix NULL deref in rds_ib_send_cqe_handler() on masked atomic completion
rds_ib_xmit_atomic() always programs a masked atomic opcode (IB_WR_MASKED_ATOMIC_CMP_AND_SWP or IB_WR_MASKED_ATOMIC_FETCH_AND_ADD) for every RDS atomic cmsg. But the completion-side switch in rds_ib_send_unmap_op() only handles the non-masked opcodes, so a masked atomic completion falls through to default and returns rm == NULL while send->s_op is left set. rds_ib_send_cqe_handler() then dereferences the NULL rm via rm->m_final_op, oopsing in softirq context. An unprivileged AF_RDS sendmsg() of an atomic cmsg over an active RDS/IB connection triggers it; on hardware that natively accepts masked atomics (mlx4, mlx5) no extra setup is needed.
RDS/IB: rds_ib_send_unmap_op: unexpected opcode 0xd in WR! Oops: general protection fault [#1] SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000190-0x0000000000000197] RIP: rds_ib_send_cqe_handler+0x25c/0xb10 (net/rds/ib_send.c:282) Call Trace: <IRQ> rds_ib_send_cqe_handler (net/rds/ib_send.c:282) poll_scq (net/rds/ib_cm.c:274) rds_ib_tasklet_fn_send (net/rds/ib_cm.c:294) tasklet_action_common (kernel/softirq.c:943) handle_softirqs (kernel/softirq.c:573) run_ksoftirqd (kernel/softirq.c:479) </IRQ> Kernel panic - not syncing: Fatal exception in interrupt
Handle the masked atomic opcodes in the same case as the non-masked ones: they map to the same struct rds_message.atomic union member, so the existing container_of()/rds_ib_send_unmap_atomic() body is correct for them.
References
- https://access.redhat.com/security/cve/CVE-2026-52939
- https://git.kernel.org/stable/c/0f22412a2f4fbbe0251c132abee045d15a90e5b6
- https://git.kernel.org/stable/c/0f7baa82a24813cdad0b06a6f8f07e4824af5ed5
- https://git.kernel.org/stable/c/34080db3e70ddf94c38512ad2331e3c3afca6cc1
- https://git.kernel.org/stable/c/4dd262f875e87653df50b138de1390ab0628e6b7
- https://git.kernel.org/stable/c/4fd34669558085bcb589aa2078a13b0ca79e360d
- https://git.kernel.org/stable/c/6e4615164d185a26badb2f376a2449f4d174a5f0
- https://git.kernel.org/stable/c/a0148342badd8c9b2e46551766a27cb76c82e715
- https://git.kernel.org/stable/c/dcf458120add64c96a6ef5cf719340453f6e6abf