CVE-2025-39758 (GCVE-0-2025-39758)
Vulnerability from cvelistv5
Published
2025-09-11 16:52
Modified
2025-09-11 16:52
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
RDMA/siw: Fix the sendmsg byte count in siw_tcp_sendpages
Ever since commit c2ff29e99a76 ("siw: Inline do_tcp_sendpages()"),
we have been doing this:
static int siw_tcp_sendpages(struct socket *s, struct page **page, int offset,
size_t size)
[...]
/* Calculate the number of bytes we need to push, for this page
* specifically */
size_t bytes = min_t(size_t, PAGE_SIZE - offset, size);
/* If we can't splice it, then copy it in, as normal */
if (!sendpage_ok(page[i]))
msg.msg_flags &= ~MSG_SPLICE_PAGES;
/* Set the bvec pointing to the page, with len $bytes */
bvec_set_page(&bvec, page[i], bytes, offset);
/* Set the iter to $size, aka the size of the whole sendpages (!!!) */
iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bvec, 1, size);
try_page_again:
lock_sock(sk);
/* Sendmsg with $size size (!!!) */
rv = tcp_sendmsg_locked(sk, &msg, size);
This means we've been sending oversized iov_iters and tcp_sendmsg calls
for a while. This has a been a benign bug because sendpage_ok() always
returned true. With the recent slab allocator changes being slowly
introduced into next (that disallow sendpage on large kmalloc
allocations), we have recently hit out-of-bounds crashes, due to slight
differences in iov_iter behavior between the MSG_SPLICE_PAGES and
"regular" copy paths:
(MSG_SPLICE_PAGES)
skb_splice_from_iter
iov_iter_extract_pages
iov_iter_extract_bvec_pages
uses i->nr_segs to correctly stop in its tracks before OoB'ing everywhere
skb_splice_from_iter gets a "short" read
(!MSG_SPLICE_PAGES)
skb_copy_to_page_nocache copy=iov_iter_count
[...]
copy_from_iter
/* this doesn't help */
if (unlikely(iter->count < len))
len = iter->count;
iterate_bvec
... and we run off the bvecs
Fix this by properly setting the iov_iter's byte count, plus sending the
correct byte count to tcp_sendmsg_locked.
References
Impacted products
| Vendor | Product | Version | |||||||
|---|---|---|---|---|---|---|---|---|---|
| ▼ | Linux | Linux |
Version: c2ff29e99a764769eb2ce3a1a5585013633ee9a6 Version: c2ff29e99a764769eb2ce3a1a5585013633ee9a6 Version: c2ff29e99a764769eb2ce3a1a5585013633ee9a6 Version: c2ff29e99a764769eb2ce3a1a5585013633ee9a6 Version: c2ff29e99a764769eb2ce3a1a5585013633ee9a6 |
||||||
|
|||||||||
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/infiniband/sw/siw/siw_qp_tx.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "5661fdd218c2799001b88c17acd19f4395e4488e",
"status": "affected",
"version": "c2ff29e99a764769eb2ce3a1a5585013633ee9a6",
"versionType": "git"
},
{
"lessThan": "673cf582fd788af12cdacfb62a6a593083542481",
"status": "affected",
"version": "c2ff29e99a764769eb2ce3a1a5585013633ee9a6",
"versionType": "git"
},
{
"lessThan": "42ebc16d9d2563f1a1ce0f05b643ee68d54fabf8",
"status": "affected",
"version": "c2ff29e99a764769eb2ce3a1a5585013633ee9a6",
"versionType": "git"
},
{
"lessThan": "edf82bc8150570167a33a7d54627d66614cbf841",
"status": "affected",
"version": "c2ff29e99a764769eb2ce3a1a5585013633ee9a6",
"versionType": "git"
},
{
"lessThan": "c18646248fed07683d4cee8a8af933fc4fe83c0d",
"status": "affected",
"version": "c2ff29e99a764769eb2ce3a1a5585013633ee9a6",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/infiniband/sw/siw/siw_qp_tx.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.5"
},
{
"lessThan": "6.5",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.103",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.43",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.15.*",
"status": "unaffected",
"version": "6.15.11",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.16.*",
"status": "unaffected",
"version": "6.16.2",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.17-rc1",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.103",
"versionStartIncluding": "6.5",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.43",
"versionStartIncluding": "6.5",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.15.11",
"versionStartIncluding": "6.5",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.16.2",
"versionStartIncluding": "6.5",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.17-rc1",
"versionStartIncluding": "6.5",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/siw: Fix the sendmsg byte count in siw_tcp_sendpages\n\nEver since commit c2ff29e99a76 (\"siw: Inline do_tcp_sendpages()\"),\nwe have been doing this:\n\nstatic int siw_tcp_sendpages(struct socket *s, struct page **page, int offset,\n size_t size)\n[...]\n /* Calculate the number of bytes we need to push, for this page\n * specifically */\n size_t bytes = min_t(size_t, PAGE_SIZE - offset, size);\n /* If we can\u0027t splice it, then copy it in, as normal */\n if (!sendpage_ok(page[i]))\n msg.msg_flags \u0026= ~MSG_SPLICE_PAGES;\n /* Set the bvec pointing to the page, with len $bytes */\n bvec_set_page(\u0026bvec, page[i], bytes, offset);\n /* Set the iter to $size, aka the size of the whole sendpages (!!!) */\n iov_iter_bvec(\u0026msg.msg_iter, ITER_SOURCE, \u0026bvec, 1, size);\ntry_page_again:\n lock_sock(sk);\n /* Sendmsg with $size size (!!!) */\n rv = tcp_sendmsg_locked(sk, \u0026msg, size);\n\nThis means we\u0027ve been sending oversized iov_iters and tcp_sendmsg calls\nfor a while. This has a been a benign bug because sendpage_ok() always\nreturned true. With the recent slab allocator changes being slowly\nintroduced into next (that disallow sendpage on large kmalloc\nallocations), we have recently hit out-of-bounds crashes, due to slight\ndifferences in iov_iter behavior between the MSG_SPLICE_PAGES and\n\"regular\" copy paths:\n\n(MSG_SPLICE_PAGES)\nskb_splice_from_iter\n iov_iter_extract_pages\n iov_iter_extract_bvec_pages\n uses i-\u003enr_segs to correctly stop in its tracks before OoB\u0027ing everywhere\n skb_splice_from_iter gets a \"short\" read\n\n(!MSG_SPLICE_PAGES)\nskb_copy_to_page_nocache copy=iov_iter_count\n [...]\n copy_from_iter\n /* this doesn\u0027t help */\n if (unlikely(iter-\u003ecount \u003c len))\n len = iter-\u003ecount;\n iterate_bvec\n ... and we run off the bvecs\n\nFix this by properly setting the iov_iter\u0027s byte count, plus sending the\ncorrect byte count to tcp_sendmsg_locked."
}
],
"providerMetadata": {
"dateUpdated": "2025-09-11T16:52:27.598Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/5661fdd218c2799001b88c17acd19f4395e4488e"
},
{
"url": "https://git.kernel.org/stable/c/673cf582fd788af12cdacfb62a6a593083542481"
},
{
"url": "https://git.kernel.org/stable/c/42ebc16d9d2563f1a1ce0f05b643ee68d54fabf8"
},
{
"url": "https://git.kernel.org/stable/c/edf82bc8150570167a33a7d54627d66614cbf841"
},
{
"url": "https://git.kernel.org/stable/c/c18646248fed07683d4cee8a8af933fc4fe83c0d"
}
],
"title": "RDMA/siw: Fix the sendmsg byte count in siw_tcp_sendpages",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2025-39758",
"datePublished": "2025-09-11T16:52:27.598Z",
"dateReserved": "2025-04-16T07:20:57.125Z",
"dateUpdated": "2025-09-11T16:52:27.598Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1",
"vulnerability-lookup:meta": {
"nvd": "{\"cve\":{\"id\":\"CVE-2025-39758\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2025-09-11T17:15:39.663\",\"lastModified\":\"2025-09-15T15:22:38.297\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nRDMA/siw: Fix the sendmsg byte count in siw_tcp_sendpages\\n\\nEver since commit c2ff29e99a76 (\\\"siw: Inline do_tcp_sendpages()\\\"),\\nwe have been doing this:\\n\\nstatic int siw_tcp_sendpages(struct socket *s, struct page **page, int offset,\\n size_t size)\\n[...]\\n /* Calculate the number of bytes we need to push, for this page\\n * specifically */\\n size_t bytes = min_t(size_t, PAGE_SIZE - offset, size);\\n /* If we can\u0027t splice it, then copy it in, as normal */\\n if (!sendpage_ok(page[i]))\\n msg.msg_flags \u0026= ~MSG_SPLICE_PAGES;\\n /* Set the bvec pointing to the page, with len $bytes */\\n bvec_set_page(\u0026bvec, page[i], bytes, offset);\\n /* Set the iter to $size, aka the size of the whole sendpages (!!!) */\\n iov_iter_bvec(\u0026msg.msg_iter, ITER_SOURCE, \u0026bvec, 1, size);\\ntry_page_again:\\n lock_sock(sk);\\n /* Sendmsg with $size size (!!!) */\\n rv = tcp_sendmsg_locked(sk, \u0026msg, size);\\n\\nThis means we\u0027ve been sending oversized iov_iters and tcp_sendmsg calls\\nfor a while. This has a been a benign bug because sendpage_ok() always\\nreturned true. With the recent slab allocator changes being slowly\\nintroduced into next (that disallow sendpage on large kmalloc\\nallocations), we have recently hit out-of-bounds crashes, due to slight\\ndifferences in iov_iter behavior between the MSG_SPLICE_PAGES and\\n\\\"regular\\\" copy paths:\\n\\n(MSG_SPLICE_PAGES)\\nskb_splice_from_iter\\n iov_iter_extract_pages\\n iov_iter_extract_bvec_pages\\n uses i-\u003enr_segs to correctly stop in its tracks before OoB\u0027ing everywhere\\n skb_splice_from_iter gets a \\\"short\\\" read\\n\\n(!MSG_SPLICE_PAGES)\\nskb_copy_to_page_nocache copy=iov_iter_count\\n [...]\\n copy_from_iter\\n /* this doesn\u0027t help */\\n if (unlikely(iter-\u003ecount \u003c len))\\n len = iter-\u003ecount;\\n iterate_bvec\\n ... and we run off the bvecs\\n\\nFix this by properly setting the iov_iter\u0027s byte count, plus sending the\\ncorrect byte count to tcp_sendmsg_locked.\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/42ebc16d9d2563f1a1ce0f05b643ee68d54fabf8\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/5661fdd218c2799001b88c17acd19f4395e4488e\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/673cf582fd788af12cdacfb62a6a593083542481\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/c18646248fed07683d4cee8a8af933fc4fe83c0d\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/edf82bc8150570167a33a7d54627d66614cbf841\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
}
}
Loading…
Loading…
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.
- 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.
Loading…