CVE-2026-64582 (GCVE-0-2026-64582)
Vulnerability from cvelistv5
Published
2026-08-05 11:25
Modified
2026-08-19 16:29
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
RDMA/rxe: Fix a use-after-free problem in rxe_mmap
rxe_mmap() removes a rxe_mmap_info struct from the pending_mmaps list
and releases pending_lock while the struct's kref is still at 1:
list_del_init(&ip->pending_mmaps);
spin_unlock_bh(&rxe->pending_lock); /* ref == 1, no lock held */
ret = remap_vmalloc_range(vma, ip->obj, 0); /* walks PTEs */
[...]
rxe_vma_open(vma); /* kref_get, ref → 2 */
remap_vmalloc_range_partial() walks PTEs without any lock.
A concurrent DESTROY_CQ ioctl on another CPU calls:
kref_put(&q->ip->ref, rxe_mmap_release) /* ref 1→0 */
vfree(ip->obj) /* clears vmalloc PTEs mid-walk */
kfree(ip) /* frees rxe_mmap_info */
This yields:
1. Kernel crash, vmalloc_to_page() returns NULL when vfree wins the
per-PTE race -> vm_insert_page(NULL) → GPF in validate_page_before_insert
2. Page UAF, vmalloc_to_page() reads a stale PTE before vfree clears
it. User VMA holds a PTE to a free'd page which might eventually get
reallocated later by vmalloc which allows the attacker to get a clean
page-level UAF.
It is worth noting that even though a page-level UAF is possible given
the strong primitive, it is statistically very difficult to achieve
given the very short time window (after the last insert_page and before
the kref_get).
The call trace are as below:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 0 UID: 1000 PID: 413 Comm: poc Not tainted 7.0.0-rc5-dirty #28 PREEMPT(lazy)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:validate_page_before_insert+0x32/0x300
Code: e5 41 57 41 56 49 89 fe 41 55 41 54 53 48 89 f3 e8 93 b5 a3 ff 48 8d 7b 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 7b 02 00 00 4c 8b 63 08 31 ff 4d 89 e5 41 83 e5
RSP: 0018:ffff88811b15f2f0 EFLAGS: 00000202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000008
RBP: ffff88811b15f318 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881181eee00
R13: 0000000000000000 R14: ffff8881181eee00 R15: ffff8881181eee20
FS: 00007b1e000f76c0(0000) GS:ffff8884268e0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007b1e00a24ac0 CR3: 0000000116eb3000 CR4: 00000000000006f0
Call Trace:
<TASK>
insert_page+0x8f/0x190
? __pfx_insert_page+0x10/0x10
? kasan_save_alloc_info+0x38/0x60
vm_insert_page+0x2e7/0x400
remap_vmalloc_range_partial+0x212/0x3e0
remap_vmalloc_range+0x6e/0xb0
? __kasan_check_write+0x14/0x30
rxe_mmap+0x2e9/0x5d0
ib_uverbs_mmap+0x1ad/0x2c0
__mmap_region+0x12c2/0x2ad0
? __pfx___mmap_region+0x10/0x10
? __sanitizer_cov_trace_switch+0x58/0xb0
? mas_prev_slot+0x360/0x39c0
? __sanitizer_cov_trace_switch+0x58/0xb0
? mas_next_slot+0x1e5b/0x2f40
? __sanitizer_cov_trace_cmp8+0x18/0x30
? unmapped_area_topdown+0x4dd/0x610
? kfree+0x1b1/0x440
? free_cpumask_var+0x16/0x30
? __kasan_slab_free+0x7d/0xa0
? __sanitizer_cov_trace_cmp8+0x18/0x30
mmap_region+0x2e6/0x3c0
do_mmap+0xa3e/0x12a0
? __pfx_do_mmap+0x10/0x10
? __kasan_check_write+0x14/0x30
? down_write_killable+0xba/0x160
? __pfx_down_write_killable+0x10/0x10
? __sanitizer_cov_trace_cmp4+0x16/0x30
vm_mmap_pgoff+0x2d4/0x4a0
? __pfx_vm_mmap_pgoff+0x10/0x10
? fget+0x1bf/0x270
ksys_mmap_pgoff+0x40c/0x690
? __sanitizer_cov_trace_const_cmp4+0x16/0x30
? __pfx_ksys_mmap_pgoff+0x10/0x10
? __kasan_check_write+0x14/0x30
? _raw_spin_trylock+0xbb/0x130
? __pfx__raw_spin_trylock+0x10/0x10
__x64_sys_mmap+0x135/0x1e0
x64_sys_c
---truncated---
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: 8700e3e7c4857d28ebaa824509934556da0b3e76 Version: 8700e3e7c4857d28ebaa824509934556da0b3e76 Version: 8700e3e7c4857d28ebaa824509934556da0b3e76 Version: 8700e3e7c4857d28ebaa824509934556da0b3e76 Version: 8700e3e7c4857d28ebaa824509934556da0b3e76 Version: 8700e3e7c4857d28ebaa824509934556da0b3e76 Version: 8700e3e7c4857d28ebaa824509934556da0b3e76 Version: 8700e3e7c4857d28ebaa824509934556da0b3e76 |
||
{
"containers": {
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{
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"product": "Linux",
"programFiles": [
"drivers/infiniband/sw/rxe/rxe_mmap.c"
],
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"vendor": "Linux",
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]
},
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"programFiles": [
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],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "4.8"
},
{
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"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.265",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.216",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.183",
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},
{
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"status": "unaffected",
"version": "6.6.145",
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},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
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"vulnerable": true
},
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},
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},
{
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},
{
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},
{
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"versionEndExcluding": "7.2",
"versionStartIncluding": "4.8",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rxe: Fix a use-after-free problem in rxe_mmap\n\nrxe_mmap() removes a rxe_mmap_info struct from the pending_mmaps list\nand releases pending_lock while the struct\u0027s kref is still at 1:\n\n list_del_init(\u0026ip-\u003epending_mmaps);\n spin_unlock_bh(\u0026rxe-\u003epending_lock); /* ref == 1, no lock held */\n ret = remap_vmalloc_range(vma, ip-\u003eobj, 0); /* walks PTEs */\n [...]\n rxe_vma_open(vma); /* kref_get, ref \u2192 2 */\n remap_vmalloc_range_partial() walks PTEs without any lock.\n\nA concurrent DESTROY_CQ ioctl on another CPU calls:\n\n kref_put(\u0026q-\u003eip-\u003eref, rxe_mmap_release) /* ref 1\u21920 */\n vfree(ip-\u003eobj) /* clears vmalloc PTEs mid-walk */\n kfree(ip) /* frees rxe_mmap_info */\n\nThis yields:\n\n 1. Kernel crash, vmalloc_to_page() returns NULL when vfree wins the\n per-PTE race -\u003e vm_insert_page(NULL) \u2192 GPF in validate_page_before_insert\n\n 2. Page UAF, vmalloc_to_page() reads a stale PTE before vfree clears\n it. User VMA holds a PTE to a free\u0027d page which might eventually get\n reallocated later by vmalloc which allows the attacker to get a clean\n page-level UAF.\n\n It is worth noting that even though a page-level UAF is possible given\n the strong primitive, it is statistically very difficult to achieve\n given the very short time window (after the last insert_page and before\n the kref_get).\n\nThe call trace are as below:\n\n Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI\n KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]\n CPU: 0 UID: 1000 PID: 413 Comm: poc Not tainted 7.0.0-rc5-dirty #28 PREEMPT(lazy)\n Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014\n RIP: 0010:validate_page_before_insert+0x32/0x300\n Code: e5 41 57 41 56 49 89 fe 41 55 41 54 53 48 89 f3 e8 93 b5 a3 ff 48 8d 7b 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 \u003c80\u003e 3c 02 00 0f 85 7b 02 00 00 4c 8b 63 08 31 ff 4d 89 e5 41 83 e5\n RSP: 0018:ffff88811b15f2f0 EFLAGS: 00000202\n RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000\n RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000008\n RBP: ffff88811b15f318 R08: 0000000000000000 R09: 0000000000000000\n R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881181eee00\n R13: 0000000000000000 R14: ffff8881181eee00 R15: ffff8881181eee20\n FS: 00007b1e000f76c0(0000) GS:ffff8884268e0000(0000) knlGS:0000000000000000\n CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 00007b1e00a24ac0 CR3: 0000000116eb3000 CR4: 00000000000006f0\n Call Trace:\n \u003cTASK\u003e\n insert_page+0x8f/0x190\n ? __pfx_insert_page+0x10/0x10\n ? kasan_save_alloc_info+0x38/0x60\n vm_insert_page+0x2e7/0x400\n remap_vmalloc_range_partial+0x212/0x3e0\n remap_vmalloc_range+0x6e/0xb0\n ? __kasan_check_write+0x14/0x30\n rxe_mmap+0x2e9/0x5d0\n ib_uverbs_mmap+0x1ad/0x2c0\n __mmap_region+0x12c2/0x2ad0\n ? __pfx___mmap_region+0x10/0x10\n ? __sanitizer_cov_trace_switch+0x58/0xb0\n ? mas_prev_slot+0x360/0x39c0\n ? __sanitizer_cov_trace_switch+0x58/0xb0\n ? mas_next_slot+0x1e5b/0x2f40\n ? __sanitizer_cov_trace_cmp8+0x18/0x30\n ? unmapped_area_topdown+0x4dd/0x610\n ? kfree+0x1b1/0x440\n ? free_cpumask_var+0x16/0x30\n ? __kasan_slab_free+0x7d/0xa0\n ? __sanitizer_cov_trace_cmp8+0x18/0x30\n mmap_region+0x2e6/0x3c0\n do_mmap+0xa3e/0x12a0\n ? __pfx_do_mmap+0x10/0x10\n ? __kasan_check_write+0x14/0x30\n ? down_write_killable+0xba/0x160\n ? __pfx_down_write_killable+0x10/0x10\n ? __sanitizer_cov_trace_cmp4+0x16/0x30\n vm_mmap_pgoff+0x2d4/0x4a0\n ? __pfx_vm_mmap_pgoff+0x10/0x10\n ? fget+0x1bf/0x270\n ksys_mmap_pgoff+0x40c/0x690\n ? __sanitizer_cov_trace_const_cmp4+0x16/0x30\n ? __pfx_ksys_mmap_pgoff+0x10/0x10\n ? __kasan_check_write+0x14/0x30\n ? _raw_spin_trylock+0xbb/0x130\n ? __pfx__raw_spin_trylock+0x10/0x10\n __x64_sys_mmap+0x135/0x1e0\n x64_sys_c\n---truncated---"
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - Triggered via local mmap on /dev/infiniband/uverbsN (ib_uverbs_mmap\u2192rxe_mmap) racing DESTROY_CQ/QP/SRQ ioctls; not reachable from RoCE/UDP packet processing.\nAC:L - Attacker controls both sides\u2014mmap of the pending CQ/QP/SRQ queue buffer and concurrent destroy that kref_puts to rxe_mmap_release\u2014and can retry unboundedly; PoC shows reliable crash.\nPR:L - uverbs_devnode() publishes /dev/infiniband/uverbs* as 0666 with no capability checks on create/mmap/destroy; once Soft-RoCE exists (admin setup), any unprivileged user (PoC UID 1000) can exploit.\nUI:N - Attacker opens uverbs, creates a CQ/QP/SRQ, then races mmap with destroy from its own threads; no victim action required.\nS:U - UAF corrupts kernel heap/vmalloc within the host kernel authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - Race frees rxe_mmap_info and vfree\u0027s the queue while remap_vmalloc_range still walks it; stale PTEs can leave a user VMA mapped to reallocated pages, enabling page-level UAF reads.\nI:H - Same page-level UAF / freed-object control yields write primitives via remapped freed pages and heap reuse, sufficient for control-flow hijacking per UAF guidance.\nA:H - Concurrent vfree during PTE walk returns NULL to vm_insert_page, causing the documented GPF/oops in validate_page_before_insert; crash is reliably repeatable."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-19T16:29:09.006Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/b810352d0916796dabe633cdb9adee9863ab4911"
},
{
"url": "https://git.kernel.org/stable/c/aef5ea8578f97f2701039600846a8bcf5f21e863"
},
{
"url": "https://git.kernel.org/stable/c/3371f2036e0f970166bbb624e25bba46d32fa18e"
},
{
"url": "https://git.kernel.org/stable/c/665fb7d22a700c66a78db0cf88c6e6a649aba9d0"
},
{
"url": "https://git.kernel.org/stable/c/e038d42cc09ca1da9d3568ce8ae062b2bfb3bc0e"
},
{
"url": "https://git.kernel.org/stable/c/e59a6aa89e0fcd1d0707832eb4654fd9ae7d31e6"
},
{
"url": "https://git.kernel.org/stable/c/3525987a392536f31a484833af258971af63b24c"
},
{
"url": "https://git.kernel.org/stable/c/35744ab3d03c5fca8c1752f53fc8fc674e14c561"
}
],
"title": "RDMA/rxe: Fix a use-after-free problem in rxe_mmap",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-64582",
"datePublished": "2026-08-05T11:25:29.082Z",
"dateReserved": "2026-07-19T15:36:31.798Z",
"dateUpdated": "2026-08-19T16:29:09.006Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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