CVE-2026-52939 (GCVE-0-2026-52939)
Vulnerability from cvelistv5 – Published: 2026-06-24 07:14 – Updated: 2026-06-24 07:14
VLAI
Title
net/rds: fix NULL deref in rds_ib_send_cqe_handler() on masked atomic completion
Summary
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.
Severity
No CVSS data available.
Assigner
References
8 references
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Linux | Linux |
Affected:
20c72bd5f5f902e5a8745d51573699605bf8d21c , < a0148342badd8c9b2e46551766a27cb76c82e715
(git)
Affected: 20c72bd5f5f902e5a8745d51573699605bf8d21c , < 4dd262f875e87653df50b138de1390ab0628e6b7 (git) Affected: 20c72bd5f5f902e5a8745d51573699605bf8d21c , < 6e4615164d185a26badb2f376a2449f4d174a5f0 (git) Affected: 20c72bd5f5f902e5a8745d51573699605bf8d21c , < 0f22412a2f4fbbe0251c132abee045d15a90e5b6 (git) Affected: 20c72bd5f5f902e5a8745d51573699605bf8d21c , < 0f7baa82a24813cdad0b06a6f8f07e4824af5ed5 (git) Affected: 20c72bd5f5f902e5a8745d51573699605bf8d21c , < dcf458120add64c96a6ef5cf719340453f6e6abf (git) Affected: 20c72bd5f5f902e5a8745d51573699605bf8d21c , < 4fd34669558085bcb589aa2078a13b0ca79e360d (git) Affected: 20c72bd5f5f902e5a8745d51573699605bf8d21c , < 34080db3e70ddf94c38512ad2331e3c3afca6cc1 (git) |
|
| Linux | Linux |
Affected:
2.6.37
Unaffected: 0 , < 2.6.37 (semver) Unaffected: 5.10.259 , ≤ 5.10.* (semver) Unaffected: 5.15.210 , ≤ 5.15.* (semver) Unaffected: 6.1.176 , ≤ 6.1.* (semver) Unaffected: 6.6.143 , ≤ 6.6.* (semver) Unaffected: 6.12.94 , ≤ 6.12.* (semver) Unaffected: 6.18.36 , ≤ 6.18.* (semver) Unaffected: 7.0.13 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix) |
{
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"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/rds: fix NULL deref in rds_ib_send_cqe_handler() on masked atomic completion\n\nrds_ib_xmit_atomic() always programs a masked atomic opcode\n(IB_WR_MASKED_ATOMIC_CMP_AND_SWP or IB_WR_MASKED_ATOMIC_FETCH_AND_ADD)\nfor every RDS atomic cmsg. But the completion-side switch in\nrds_ib_send_unmap_op() only handles the non-masked opcodes, so a masked\natomic completion falls through to default and returns rm == NULL while\nsend-\u003es_op is left set. rds_ib_send_cqe_handler() then dereferences the\nNULL rm via rm-\u003em_final_op, oopsing in softirq context. An unprivileged\nAF_RDS sendmsg() of an atomic cmsg over an active RDS/IB connection\ntriggers it; on hardware that natively accepts masked atomics (mlx4,\nmlx5) no extra setup is needed.\n\n RDS/IB: rds_ib_send_unmap_op: unexpected opcode 0xd in WR!\n Oops: general protection fault [#1] SMP KASAN\n KASAN: null-ptr-deref in range [0x0000000000000190-0x0000000000000197]\n RIP: rds_ib_send_cqe_handler+0x25c/0xb10 (net/rds/ib_send.c:282)\n Call Trace:\n \u003cIRQ\u003e\n rds_ib_send_cqe_handler (net/rds/ib_send.c:282)\n poll_scq (net/rds/ib_cm.c:274)\n rds_ib_tasklet_fn_send (net/rds/ib_cm.c:294)\n tasklet_action_common (kernel/softirq.c:943)\n handle_softirqs (kernel/softirq.c:573)\n run_ksoftirqd (kernel/softirq.c:479)\n \u003c/IRQ\u003e\n Kernel panic - not syncing: Fatal exception in interrupt\n\nHandle the masked atomic opcodes in the same case as the non-masked\nones: they map to the same struct rds_message.atomic union member, so\nthe existing container_of()/rds_ib_send_unmap_atomic() body is correct\nfor them."
}
],
"providerMetadata": {
"dateUpdated": "2026-06-24T07:14:28.622Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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"url": "https://git.kernel.org/stable/c/a0148342badd8c9b2e46551766a27cb76c82e715"
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"url": "https://git.kernel.org/stable/c/4dd262f875e87653df50b138de1390ab0628e6b7"
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{
"url": "https://git.kernel.org/stable/c/6e4615164d185a26badb2f376a2449f4d174a5f0"
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{
"url": "https://git.kernel.org/stable/c/0f22412a2f4fbbe0251c132abee045d15a90e5b6"
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"url": "https://git.kernel.org/stable/c/0f7baa82a24813cdad0b06a6f8f07e4824af5ed5"
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"url": "https://git.kernel.org/stable/c/dcf458120add64c96a6ef5cf719340453f6e6abf"
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{
"url": "https://git.kernel.org/stable/c/4fd34669558085bcb589aa2078a13b0ca79e360d"
},
{
"url": "https://git.kernel.org/stable/c/34080db3e70ddf94c38512ad2331e3c3afca6cc1"
}
],
"title": "net/rds: fix NULL deref in rds_ib_send_cqe_handler() on masked atomic completion",
"x_generator": {
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}
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"cveId": "CVE-2026-52939",
"datePublished": "2026-06-24T07:14:28.622Z",
"dateReserved": "2026-06-09T07:44:35.370Z",
"dateUpdated": "2026-06-24T07:14:28.622Z",
"state": "PUBLISHED"
},
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"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-52939",
"date": "2026-06-24",
"epss": "0.00164",
"percentile": "0.05936"
}
}
}
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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
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- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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