packet: use ubuf_info completion for TX_RING packets
In the Linux kernel, the following vulnerability has been resolved: packet: use ubuf_info completion for TX_RING packets tpacket_snd sends skbs with frags pointing into its ring slots. Slots are released when skb->destructor is called. A call to skb_orphan calls skb->destructor before the skb is freed. This can cause the slot to be reused while still linked into the skb. Switch to standard zerocopy completion (ubuf_info) so the slot is only released once all references to the payload are freed or copied. Restore skb->destructor to standard sock_wfree. The ubuf_info completion callback can be called with a NULL skb, but only from net_zcopy_put and related API, used by zerocopy implementations that hold their own reference on the uarg, such as MSG_ZEROCOPY. This uarg is only ever completed from skb_zcopy_clear, so skb is always set. To prevent userspace from aliasing in-flight state on shared ring slots, allocate tpacket_uarg per packet, rather than per slot. This adds a small allocation to the transmit path. Use standard kmalloc to allow backporting to stable kernels. The uarg holds an sk_wmem_alloc reference, rather than an sk_refcnt reference. packet_free_tx_ring waits on sk_wmem_alloc before freeing the ring pages. Always allocate vec->deferred for tx_ring so page-backed rings also wait on sk_wmem_alloc when skb_copy_ubufs drops page refs before calling tpacket_ubuf_complete. Drop the tx_ring.pg_vec test that tpacket_destruct_skb performed before accessing the slot. The sk_
CVE-2026-98503
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-2026-98503
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": "5cd8d46ea1562be80063f53c7c6a5f40224de623",
"lessThan": "e67c455d79fbf709a94965f09a2be6bf4f4ba5fd",
"versionType": "git"
},
{
"status": "affected",
"version": "5cd8d46ea1562be80063f53c7c6a5f40224de623",
"lessThan": "eda9bcb721f15a93746a99eabda33d80b86404fd",
"versionType": "git"
},
{
"status": "affected",
"version": "5cd8d46ea1562be80063f53c7c6a5f40224de623",
"lessThan": "2a0c9afefc0ecea2cc30ccfbbbc98182a0986191",
"versionType": "git"
},
{
"status": "affected",
"version": "5cd8d46ea1562be80063f53c7c6a5f40224de623",
"lessThan": "9518405613863d0bf0700927a21367f5942cf058",
"versionType": "git"
},
{
"status": "affected",
"version": "67f6fba765ef8cb19089d476e3c367212a2fbdfd",
"versionType": "git"
},
{
"status": "affected",
"version": "f2a67e68dbaeae7c88e5522873d7b908911f9f77",
"versionType": "git"
},
{
"status": "affected",
"version": "4.14.86",
"lessThan": "4.15",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.19.7",
"lessThan": "4.20",
"versionType": "semver"
}
],
"programFiles": [
"include/linux/skbuff.h",
"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": "4.20"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.20",
"versionType": "semver"
},
{
"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": [
"include/linux/skbuff.h",
"net/packet/af_packet.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-98503
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #38538 · Revision 1
- Added to Heist Feed
- Publisher date