af_packet: fix integer overflow in prb_calc_retire_blk_tmo()
In the Linux kernel, the following vulnerability has been resolved: af_packet: fix integer overflow in prb_calc_retire_blk_tmo() prb_calc_retire_blk_tmo() computes in 32-bit int arithmetic: mbits = (blk_size_in_bytes * 8) / (1024 * 1024); If I'm reading the validation right, tp_block_size is user controlled and packet_set_ring() only rejects values that are <= 0 as int or not page aligned, so a 256MiB block goes right through (and alloc_one_pg_vec_page() even has a vzalloc fallback for it). 0x10000000 * 8 wraps to INT_MIN, and on a NIC reporting 1 Gbps (div == 1) the function ends up returning -2047. The condition is actually (8 * size) mod 2^32 >= 2^31 && div == 1, so the trigger set is [256,512), [768,1024), [1280,1536) and [1792,2048) MiB. Other sizes wrap to non-negative values and faster links divide the unsigned value back below 2^31, which is why this doesn't blow up for everyone. What makes it fatal is what happens next in init_prb_bdqc(): p1->interval_ktime = ms_to_ktime(prb_calc_retire_blk_tmo(...)); hrtimer_start(&p1->retire_blk_timer, p1->interval_ktime, HRTIMER_MODE_REL_SOFT); A negative relative timeout expires immediately. The callback unconditionally returns HRTIMER_RESTART, and hrtimer_forward() turns the negative interval into hrtimer_resolution: if (interval < hrtimer_resolution) interval = hrtimer_resolution; So the SOFT timer re-fires at the maximum rate forever, holding sk_receive_queue.lock each pass. One CPU spins in softirq until the socket is closed.
CVE-2026-98547
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-98547
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "f6fb8f100b807378fda19e83e5ac6828b638603a",
"lessThan": "02afd75649a4e001031ed82153a5c39312ec0737",
"versionType": "git"
},
{
"status": "affected",
"version": "f6fb8f100b807378fda19e83e5ac6828b638603a",
"lessThan": "eb5b3838b9200dac04bfe33483db0ee8287456fb",
"versionType": "git"
},
{
"status": "affected",
"version": "f6fb8f100b807378fda19e83e5ac6828b638603a",
"lessThan": "297acc571d5813db76b147c745b91031d5f9c960",
"versionType": "git"
},
{
"status": "affected",
"version": "f6fb8f100b807378fda19e83e5ac6828b638603a",
"lessThan": "be1aacff399d519cc48d6b34354a54dd79041140",
"versionType": "git"
},
{
"status": "affected",
"version": "f6fb8f100b807378fda19e83e5ac6828b638603a",
"lessThan": "b2bcc6a254d6f27823a56787668ae4ee8cdb6e71",
"versionType": "git"
},
{
"status": "affected",
"version": "f6fb8f100b807378fda19e83e5ac6828b638603a",
"lessThan": "6279211e7d2456ecd195d236c9ee5e5c6fa5a17a",
"versionType": "git"
},
{
"status": "affected",
"version": "f6fb8f100b807378fda19e83e5ac6828b638603a",
"lessThan": "218a944b9e035d4b47d59c69af6ca13319da15fb",
"versionType": "git"
},
{
"status": "affected",
"version": "f6fb8f100b807378fda19e83e5ac6828b638603a",
"lessThan": "56d82862a0a243ac14ba11b6d7b57ddc2d064b95",
"versionType": "git"
}
],
"programFiles": [
"net/packet/af_packet.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "3.2"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "3.2",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.271",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.222",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.189",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.158",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.112",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.55",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.9",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/packet/af_packet.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-98547
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #38572 · Revision 1
- Added to Heist Feed
- Publisher date