CVE-2026-80852 (GCVE-0-2026-80852)
Vulnerability from cvelistv5
Published
2026-09-04 15:55
Modified
2026-09-04 15:55
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
tls: device: fix out-of-bounds write in tls_append_frag()
Found with syzkaller and a local syzbot instance running on top of a
netdevsim TLS offload emulation; tls_device.c is otherwise only reachable
on a machine with a NIC that implements the offload.
tls_push_data() only checks whether the open record still has room for
another frag at the bottom of its loop, and the MSG_MORE early break
skips that check. The record survives to the next syscall with the frag
count it already had, and tls_append_frag() does not check either, so
with TLS_TX_ZEROCOPY_RO every splice(SPLICE_F_MORE) of a byte or two adds
a non-coalescing pipe page and num_frags walks off the end of
tls_record_info.frags[MAX_SKB_FRAGS]. Once the record is pushed,
tls_push_record() runs the same index over sg_tx_data[MAX_SKB_FRAGS] and
the sg_set_page() writes land on the destruct_work that follows it, which
the workqueue then calls.
The byte limit is fine because copy drops to 0 and the loop falls through
to the same check; the frag count has no such feedback.
Push the record rather than keep a full one open, which is what a plain
TCP socket does - tcp_sendmsg_locked() uses tcp_mark_push() and
new_segment in both the copy and the MSG_SPLICE_PAGES paths, and tls_sw
already sets full_record when the sk_msg ring fills up, MSG_MORE or not.
BUG: KASAN: slab-out-of-bounds in tls_append_frag ( net/tls/tls_device.c:269)
Write of size 8 at addr ffff8881104d1530 by task tls_oob/450
CPU: 2 UID: 0 PID: 450 Comm: tls_oob Not tainted 7.2.0-rc7+ #329 PREEMPT
Call Trace:
<TASK>
dump_stack_lvl (lib/dump_stack.c:94 lib/dump_stack.c:120)
print_report (mm/kasan/report.c:378 mm/kasan/report.c:482)
kasan_report (mm/kasan/report.c:595)
tls_append_frag (net/tls/tls_device.c:269)
tls_push_data (net/tls/tls_device.c:518)
tls_device_sendmsg (net/tls/tls_device.c:583)
inet_sendmsg (net/ipv4/af_inet.c:865)
sock_sendmsg (net/socket.c:775 net/socket.c:790 net/socket.c:813)
splice_to_socket (fs/splice.c:884)
do_splice (fs/splice.c:936 fs/splice.c:1349)
__do_splice (fs/splice.c:1431)
__x64_sys_splice (fs/splice.c:1634 fs/splice.c:1616)
do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)
</TASK>
and, once the record is pushed:
UBSAN: array-index-out-of-bounds in net/tls/tls_device.c:300:24
index 18 is out of range for type 'skb_frag_t [17]'
UBSAN: array-index-out-of-bounds in net/tls/tls_device.c:301:41
index 18 is out of range for type 'scatterlist [17]'
UBSAN: array-index-out-of-bounds in net/tls/tls_device.c:302:39
index 18 is out of range for type 'scatterlist [17]'
UBSAN: array-index-out-of-bounds in net/tls/tls_device.c:307:38
index 26 is out of range for type 'scatterlist [17]'
kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
BUG: unable to handle page fault for address: ffffea000411a680
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0011) - permissions violation
Oops: Oops: 0011 [#1] SMP KASAN PTI
Workqueue: ktls_device_destruct 0xffffea000411a680
RIP: 0010:0xffffea000411a680
Call Trace:
<TASK>
worker_thread (kernel/workqueue.c:3405 kernel/workqueue.c:3486)
kthread (kernel/kthread.c:436)
ret_from_fork (arch/x86/kernel/process.c:158)
ret_from_fork_asm (arch/x86/entry/entry_64.S:245)
</TASK>
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: e8f69799810c32dd40c6724d829eccc70baad07f Version: e8f69799810c32dd40c6724d829eccc70baad07f Version: e8f69799810c32dd40c6724d829eccc70baad07f Version: e8f69799810c32dd40c6724d829eccc70baad07f Version: e8f69799810c32dd40c6724d829eccc70baad07f Version: e8f69799810c32dd40c6724d829eccc70baad07f Version: e8f69799810c32dd40c6724d829eccc70baad07f |
||
{
"containers": {
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{
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"programFiles": [
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],
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"programFiles": [
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],
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"vendor": "Linux",
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"version": "0",
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},
{
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"version": "6.1.187",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
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"version": "6.6.156",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.108",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.49",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.13",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.3",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3-rc1",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
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],
"negate": false,
"operator": "OR"
}
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],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntls: device: fix out-of-bounds write in tls_append_frag()\n\nFound with syzkaller and a local syzbot instance running on top of a\nnetdevsim TLS offload emulation; tls_device.c is otherwise only reachable\non a machine with a NIC that implements the offload.\n\ntls_push_data() only checks whether the open record still has room for\nanother frag at the bottom of its loop, and the MSG_MORE early break\nskips that check. The record survives to the next syscall with the frag\ncount it already had, and tls_append_frag() does not check either, so\nwith TLS_TX_ZEROCOPY_RO every splice(SPLICE_F_MORE) of a byte or two adds\na non-coalescing pipe page and num_frags walks off the end of\ntls_record_info.frags[MAX_SKB_FRAGS]. Once the record is pushed,\ntls_push_record() runs the same index over sg_tx_data[MAX_SKB_FRAGS] and\nthe sg_set_page() writes land on the destruct_work that follows it, which\nthe workqueue then calls.\n\nThe byte limit is fine because copy drops to 0 and the loop falls through\nto the same check; the frag count has no such feedback.\n\nPush the record rather than keep a full one open, which is what a plain\nTCP socket does - tcp_sendmsg_locked() uses tcp_mark_push() and\nnew_segment in both the copy and the MSG_SPLICE_PAGES paths, and tls_sw\nalready sets full_record when the sk_msg ring fills up, MSG_MORE or not.\n\n BUG: KASAN: slab-out-of-bounds in tls_append_frag ( net/tls/tls_device.c:269)\n Write of size 8 at addr ffff8881104d1530 by task tls_oob/450\n\n CPU: 2 UID: 0 PID: 450 Comm: tls_oob Not tainted 7.2.0-rc7+ #329 PREEMPT\n Call Trace:\n \u003cTASK\u003e\n dump_stack_lvl (lib/dump_stack.c:94 lib/dump_stack.c:120)\n print_report (mm/kasan/report.c:378 mm/kasan/report.c:482)\n kasan_report (mm/kasan/report.c:595)\n tls_append_frag (net/tls/tls_device.c:269)\n tls_push_data (net/tls/tls_device.c:518)\n tls_device_sendmsg (net/tls/tls_device.c:583)\n inet_sendmsg (net/ipv4/af_inet.c:865)\n sock_sendmsg (net/socket.c:775 net/socket.c:790 net/socket.c:813)\n splice_to_socket (fs/splice.c:884)\n do_splice (fs/splice.c:936 fs/splice.c:1349)\n __do_splice (fs/splice.c:1431)\n __x64_sys_splice (fs/splice.c:1634 fs/splice.c:1616)\n do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)\n entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)\n \u003c/TASK\u003e\n\nand, once the record is pushed:\n\n UBSAN: array-index-out-of-bounds in net/tls/tls_device.c:300:24\n index 18 is out of range for type \u0027skb_frag_t [17]\u0027\n UBSAN: array-index-out-of-bounds in net/tls/tls_device.c:301:41\n index 18 is out of range for type \u0027scatterlist [17]\u0027\n UBSAN: array-index-out-of-bounds in net/tls/tls_device.c:302:39\n index 18 is out of range for type \u0027scatterlist [17]\u0027\n UBSAN: array-index-out-of-bounds in net/tls/tls_device.c:307:38\n index 26 is out of range for type \u0027scatterlist [17]\u0027\n\n kernel tried to execute NX-protected page - exploit attempt? (uid: 0)\n BUG: unable to handle page fault for address: ffffea000411a680\n #PF: supervisor instruction fetch in kernel mode\n #PF: error_code(0x0011) - permissions violation\n Oops: Oops: 0011 [#1] SMP KASAN PTI\n Workqueue: ktls_device_destruct 0xffffea000411a680\n RIP: 0010:0xffffea000411a680\n Call Trace:\n \u003cTASK\u003e\n worker_thread (kernel/workqueue.c:3405 kernel/workqueue.c:3486)\n kthread (kernel/kthread.c:436)\n ret_from_fork (arch/x86/kernel/process.c:158)\n ret_from_fork_asm (arch/x86/entry/entry_64.S:245)\n \u003c/TASK\u003e"
}
],
"providerMetadata": {
"dateUpdated": "2026-09-04T15:55:02.806Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/03ced5da6120965d80ed56dbb7d78fa5c9128906"
},
{
"url": "https://git.kernel.org/stable/c/a832d7cb09da2a8e4e9734b4be14d3e76169d805"
},
{
"url": "https://git.kernel.org/stable/c/b7f10d4ff987bda038df90052cd4a1434a7412d4"
},
{
"url": "https://git.kernel.org/stable/c/fadbc1ed2a872a8649a44cf9e1cf9621fc58cd6e"
},
{
"url": "https://git.kernel.org/stable/c/cd7e875b89597f3498917af764758391338d1802"
},
{
"url": "https://git.kernel.org/stable/c/7e1208c135618358da5d7d6664874dc6e53c62fc"
},
{
"url": "https://git.kernel.org/stable/c/b17cf742eaad70ae29ac558cefb3aa9bbeea03d4"
}
],
"title": "tls: device: fix out-of-bounds write in tls_append_frag()",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-80852",
"datePublished": "2026-09-04T15:55:02.806Z",
"dateReserved": "2026-08-26T14:34:25.797Z",
"dateUpdated": "2026-09-04T15:55:02.806Z",
"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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