net: tap: NULL pointer derefence in dev_parse_header_protocol when skb->dev is null (CVE-2022-50073) | HOL Guard CVE

Medium · CVSS 5.5CVE-2022-50073

net: tap: NULL pointer derefence in dev_parse_header_protocol when skb->dev is null

Answer in brief

CVE-2022-50073 records a Medium severity (CVSS 5.5) vulnerability in net: tap: NULL pointer derefence in dev_parse_header_protocol when skb->dev is null. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jun 18, 2025Updated Aug 12, 2026Source checked Sep 28, 2026First seen by HOL Aug 12, 2026Material review Aug 12, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 5.5
Exploitation: Not marked as known exploited
Affected software: 10 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 5.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Affected products and reported versions
Product	Affected versions	Fixed versions
cpe:2.3:o:linux:linux_kernel::::::::	Not reported	Not reported
cpe:2.3:o:linux:linux_kernel:5.12:-::::::	Not reported	Not reported
cpe:2.3:o:linux:linux_kernel:5.12:rc3::::::	Not reported	Not reported
cpe:2.3:o:linux:linux_kernel:5.12:rc4::::::	Not reported	Not reported
cpe:2.3:o:linux:linux_kernel:5.12:rc5::::::	Not reported	Not reported
cpe:2.3:o:linux:linux_kernel:5.12:rc6::::::	Not reported	Not reported
cpe:2.3:o:linux:linux_kernel:5.12:rc7::::::	Not reported	Not reported
cpe:2.3:o:linux:linux_kernel:5.12:rc8::::::	Not reported	Not reported

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=faa3baa2828c5e1c4374f3e60041f75c64f5fcb6 <8f90163f9e013c8fc791aab338aab44a46044cfc \|\| >=924a9bc362a5223cd448ca08c3dde21235adc310 <447ba770cfe798925f4923548b367fd49f0ee5f0 \|\| >=924a9bc362a5223cd448ca08c3dde21235adc310 <dd29648fcf69339713f2d25f7014ae905dcdfc18 \|\| >=924a9bc362a5223cd448ca08c3dde21235adc310 <4f61f133f354853bc394ec7d6028adb9b02dd701 \|\| ea3fb2ce5fa794d02135f5c079e05cd6fc3f545d \|\| 54ef8243c3c8e90f1ea5792e6752e021a25c8eb3 \|\| ca278267d6cd9544645731732455b6b20cb0e895 \|\| 99b1d3f74b9ef72c2f74c8e4c078e1bc0706e748 \|\| >=5.10.24 <5.10.258 \|\| >=4.14.226 <4.15 \|\| >=4.19.181 <4.20 \|\| >=5.4.106 <5.5 \|\| >=5.11.7 <5.12	8f90163f9e013c8fc791aab338aab44a46044cfc, 447ba770cfe798925f4923548b367fd49f0ee5f0, dd29648fcf69339713f2d25f7014ae905dcdfc18, 4f61f133f354853bc394ec7d6028adb9b02dd701, 5.10.258, 4.15, 4.20, 5.5, 5.12
Linux/Linuxgeneric	5.12	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 8f90163f9e013c8fc791aab338aab44a46044cfc if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Jun 18, 2025
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 12, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 12, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: net: tap: NULL pointer derefence in dev_parse_header_protocol when skb->dev is null Fixes a NULL pointer derefence bug triggered from tap driver. When tap_get_user calls virtio_net_hdr_to_skb the skb->dev is null (in tap.c skb->dev is set after the call to virtio_net_hdr_to_skb) virtio_net_hdr_to_skb calls dev_parse_header_protocol which needs skb->dev field to be valid. The line that trigers the bug is in dev_parse_header_protocol (dev is at offset 0x10 from skb and is stored in RAX register) if (!dev->header_ops || !dev->header_ops->parse_protocol) 22e1: mov 0x10(%rbx),%rax 22e5: mov 0x230(%rax),%rax Setting skb->dev before the call in tap.c fixes the issue. BUG: kernel NULL pointer dereference, address: 0000000000000230 RIP: 0010:virtio_net_hdr_to_skb.constprop.0+0x335/0x410 [tap] Code: c0 0f 85 b7 fd ff ff eb d4 41 39 c6 77 cf 29 c6 48 89 df 44 01 f6 e8 7a 79 83 c1 48 85 c0 0f 85 d9 fd ff ff eb b7 48 8b 43 10 <48> 8b 80 30 02 00 00 48 85 c0 74 55 48 8b 40 28 48 85 c0 74 4c 48 RSP: 0018:ffffc90005c27c38 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff888298f25300 RCX: 0000000000000010 RDX: 0000000000000005 RSI: ffffc90005c27cb6 RDI: ffff888298f25300 RBP: ffffc90005c27c80 R08: 00000000ffffffea R09: 00000000000007e8 R10: ffff88858ec77458 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000014 R14: ffffc90005c27e08 R15: ffffc90005c27cb6 FS: 0000000000000000(0000) GS:ffff88858ec40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000230 CR3: 0000000281408006 CR4: 00000000003706e0 Call Trace: tap_get_user+0x3f1/0x540 [tap] tap_sendmsg+0x56/0x362 [tap] ? get_tx_bufs+0xc2/0x1e0 [vhost_net] handle_tx_copy+0x114/0x670 [vhost_net] handle_tx+0xb0/0xe0 [vhost_net] handle_tx_kick+0x15/0x20 [vhost_net] vhost_worker+0x7b/0xc0 [vhost] ? vhost_vring_call_reset+0x40/0x40 [vhost] kthread+0xfa/0x120 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x1f/0x30

Quoted source text, attributed separately from HOL analysis.