Description
In the Linux kernel, the following vulnerability has been resolved:
net: dsa: tag_brcm: legacy FCS: request needed tailroom
The legacy FCS tagger calculates the CRC over skb->len bytes starting at
skb->data. When a nonlinear skb reaches the tagger, this reads past the
linear head into unrelated slab memory.
The tagger appends an Ethernet FCS but does not declare that tailroom. As a
result, DSA leaves NETIF_F_SG and NETIF_F_FRAGLIST enabled on the user
port, and nonlinear skbs can reach the CRC calculation.
Declare the required tailroom. DSA will then clear those features and the
networking core will linearize skbs before the tagger runs.
A KASAN-enabled dsa_loop test using this tagger reports:
BUG: KASAN: slab-out-of-bounds in crc32_le
Read of size 1 at addr ffff8880397086c0 by task exp/135
Call Trace:
crc32_le (lib/crc/crc32-main.c:38)
brcm_leg_fcs_tag_xmit (net/dsa/tag_brcm.c:343)
dsa_user_xmit (net/dsa/user.c:942)
dev_hard_start_xmit (net/core/dev.c:3937)
__dev_queue_xmit (net/core/dev.c:4926)
packet_sendmsg (net/packet/af_packet.c:3110)
__sys_sendto (net/socket.c:2281)
The buggy address belongs to the object at ffff888039708400
which belongs to the cache skbuff_small_head of size 704
The buggy address is located 0 bytes to the right of
allocated 704-byte region [ffff888039708400, ffff8880397086c0)
net: dsa: tag_brcm: legacy FCS: request needed tailroom
The legacy FCS tagger calculates the CRC over skb->len bytes starting at
skb->data. When a nonlinear skb reaches the tagger, this reads past the
linear head into unrelated slab memory.
The tagger appends an Ethernet FCS but does not declare that tailroom. As a
result, DSA leaves NETIF_F_SG and NETIF_F_FRAGLIST enabled on the user
port, and nonlinear skbs can reach the CRC calculation.
Declare the required tailroom. DSA will then clear those features and the
networking core will linearize skbs before the tagger runs.
A KASAN-enabled dsa_loop test using this tagger reports:
BUG: KASAN: slab-out-of-bounds in crc32_le
Read of size 1 at addr ffff8880397086c0 by task exp/135
Call Trace:
crc32_le (lib/crc/crc32-main.c:38)
brcm_leg_fcs_tag_xmit (net/dsa/tag_brcm.c:343)
dsa_user_xmit (net/dsa/user.c:942)
dev_hard_start_xmit (net/core/dev.c:3937)
__dev_queue_xmit (net/core/dev.c:4926)
packet_sendmsg (net/packet/af_packet.c:3110)
__sys_sendto (net/socket.c:2281)
The buggy address belongs to the object at ffff888039708400
which belongs to the cache skbuff_small_head of size 704
The buggy address is located 0 bytes to the right of
allocated 704-byte region [ffff888039708400, ffff8880397086c0)
Published:
2026-09-25
Score:
n/a
EPSS:
n/a
KEV:
No
Impact:
n/a
Action:
n/a
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
||||||||||||||||||
| Linux | Linux | affected |
|
No data.
No data.
No data available yet.
Remediation
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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Advisories
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References
History
Fri, 25 Sep 2026 10:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: net: dsa: tag_brcm: legacy FCS: request needed tailroom The legacy FCS tagger calculates the CRC over skb->len bytes starting at skb->data. When a nonlinear skb reaches the tagger, this reads past the linear head into unrelated slab memory. The tagger appends an Ethernet FCS but does not declare that tailroom. As a result, DSA leaves NETIF_F_SG and NETIF_F_FRAGLIST enabled on the user port, and nonlinear skbs can reach the CRC calculation. Declare the required tailroom. DSA will then clear those features and the networking core will linearize skbs before the tagger runs. A KASAN-enabled dsa_loop test using this tagger reports: BUG: KASAN: slab-out-of-bounds in crc32_le Read of size 1 at addr ffff8880397086c0 by task exp/135 Call Trace: crc32_le (lib/crc/crc32-main.c:38) brcm_leg_fcs_tag_xmit (net/dsa/tag_brcm.c:343) dsa_user_xmit (net/dsa/user.c:942) dev_hard_start_xmit (net/core/dev.c:3937) __dev_queue_xmit (net/core/dev.c:4926) packet_sendmsg (net/packet/af_packet.c:3110) __sys_sendto (net/socket.c:2281) The buggy address belongs to the object at ffff888039708400 which belongs to the cache skbuff_small_head of size 704 The buggy address is located 0 bytes to the right of allocated 704-byte region [ffff888039708400, ffff8880397086c0) | |
| Title | net: dsa: tag_brcm: legacy FCS: request needed tailroom | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-25T10:22:22.632Z
Reserved: 2026-09-24T16:01:01.158Z
Link: CVE-2026-97614
Vulnrichment
No data.
NVD
No data.
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.