CVE-2026-53247
In the Linux kernel, the following vulnerability has been resolved: net: ethernet: mtk_eth_soc: Fix use-after-free in metadata dst teardown mtk_free_dev() calls metadata_dst_free() which frees the metadata_dst with kfree() immediately, bypassing the RCU…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.47%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
In the Linux kernel, the following vulnerability has been resolved: net: ethernet: mtk_eth_soc: Fix use-after-free in metadata dst teardown mtk_free_dev() calls metadata_dst_free() which frees the metadata_dst with kfree() immediately, bypassing the RCU grace period. In the RX path, skb_dst_set_noref() sets a non-refcounted pointer from the skb to the metadata_dst. This function requires RCU read-side protection and the dst must remain valid until all RCU readers complete. Since metadata_dst_free() calls kfree() directly, a use-after-free can occur if any skb still holds a noref pointer to the dst when the driver tears it down. Replace metadata_dst_free() with dst_release() which properly goes through the refcount path: when the refcount drops to zero, it schedules the actual free via call_rcu_hurry(), ensuring all RCU readers have completed before the memory is freed.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.47% probability · 39th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/2d86aeb46d5f69c704065a8c69822582787272a1Patch
- https://git.kernel.org/stable/c/459c6f35c58cf0fd5247e55d73ddaa29571d9b7ePatch
- https://git.kernel.org/stable/c/72775977e89c25c99ee84d2c5baa3f86a8ba5cb4Patch
- https://git.kernel.org/stable/c/80df409e1a483676826a6c66e693dba6ac507751Patch
- https://git.kernel.org/stable/c/e634408d2b0cd939cfe019398a21fb47b7a8ffe3Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.