CVE-2026-97614 net: dsa: tag_brcm: legacy FCS: request needed tailroom
A local attacker can trigger a slab-out-of-bounds read in the Linux kernel's Broadcom DSA tagger, potentially causing a crash or leaking memory.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-97614?
CVE-2026-97614 is a memory corruption vulnerability in Linux, published on 25 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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)
Which versions are affected by CVE-2026-97614?
How do I fix CVE-2026-97614?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-97614 being exploited?
There is no known exploitation of CVE-2026-97614 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-97614, DEBIAN-CVE-2026-97614, GHSA-3px2-442r-8h6r, UBUNTU-CVE-2026-97614.