Paper/Archive/CVE-2026-72393

CVE-2026-72393

Linux Linux — eth: fbnic: don't cache shinfo across skb realloc

Description · from the CVE record

In the Linux kernel, the following vulnerability has been resolved: eth: fbnic: don't cache shinfo across skb realloc fbnic_tx_lso() calls skb_cow_head() which may reallocate the skb including the shared info. We can't use the pointer calculated before the call. BUG: KASAN: slab-use-after-free in fbnic_tx_lso.isra.0+0x668/0x8e0 Read of size 4 at addr ff110000262edd98 by task swapper/5/0 Call Trace: fbnic_tx_lso.isra.0+0x668/0x8e0 fbnic_xmit_frame+0x622/0xba0 dev_hard_start_xmit+0xf4/0x620 Allocated by task 8653: __alloc_skb+0x11e/0x5f0 alloc_skb_with_frags+0xcc/0x6c0 sock_alloc_send_pskb+0x327/0x3f0 __ip_append_data+0x188b/0x47a0 ip_make_skb+0x24a/0x300 udp_sendmsg+0x14d2/0x21e0 Freed by task 0: kfree+0x123/0x5a0 pskb_expand_head+0x36c/0xfa0 fbnic_tx_lso.isra.0+0x500/0x8e0 fbnic_xmit_frame+0x622/0xba0 dev_hard_start_xmit+0xf4/0x620 sch_direct_xmit+0x25b/0x1100 The buggy address belongs to the object at ff110000262edc40 which belongs to the cache skbuff_small_head of size 640 The buggy address is located 344 bytes inside of freed 640-byte region [ff110000262edc40, ff110000262ede

Affected

ProductAffectedFixed inSource
Linuxb0b0f52042acb324cd39fbefb2b1ae83af8f8ae1 – < 83df3e2594cd78aa40b1246a19879abb4891945b83df3e2594cd78aa40b1246a19879abb4891945bCNA
Linuxb0b0f52042acb324cd39fbefb2b1ae83af8f8ae1 – < 21f304c2aae46625e050c28d979f4b9d83faa85e21f304c2aae46625e050c28d979f4b9d83faa85eCNA
Linuxb0b0f52042acb324cd39fbefb2b1ae83af8f8ae1 – < 62b68b774f06bf52e329f254f0199bc43d350ccf62b68b774f06bf52e329f254f0199bc43d350ccfCNA
Linux6.156.18.40CNA

Scores by source

Linux (CNA)9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

refgit.kernel.org/stable/c/83df3e2594cd78aa40b1246a19879abb4891945brefgit.kernel.org/stable/c/21f304c2aae46625e050c28d979f4b9d83faa85erefgit.kernel.org/stable/c/62b68b774f06bf52e329f254f0199bc43d350ccf