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 breakdown
Affected products
- Linux / Linux2d7605a729062bb554f03c5983d8cfb8c0b42e9c – 72775977e89c25c99ee84d2c5baa3f86a8ba5cb4
- Linux / Linux2d7605a729062bb554f03c5983d8cfb8c0b42e9c – 459c6f35c58cf0fd5247e55d73ddaa29571d9b7e
- Linux / Linux2d7605a729062bb554f03c5983d8cfb8c0b42e9c – e634408d2b0cd939cfe019398a21fb47b7a8ffe3
- Linux / Linux2d7605a729062bb554f03c5983d8cfb8c0b42e9c – 2d86aeb46d5f69c704065a8c69822582787272a1
- Linux / Linux2d7605a729062bb554f03c5983d8cfb8c0b42e9c – 80df409e1a483676826a6c66e693dba6ac507751
- Linux / Linux6.2 – 6.2
- Linux / Linux0 – 6.2
- Linux / Linux6.6.143 – 6.6.*
- Linux / Linux6.12.94 – 6.12.*
- Linux / Linux6.18.36 – 6.18.*
- Linux / Linux7.0.13 – 7.0.*
- Linux / Linux7.1 – *
References
- MISChttps://git.kernel.org/stable/c/72775977e89c25c99ee84d2c5baa3f86a8ba5cb4
- MISChttps://git.kernel.org/stable/c/459c6f35c58cf0fd5247e55d73ddaa29571d9b7e
- MISChttps://git.kernel.org/stable/c/e634408d2b0cd939cfe019398a21fb47b7a8ffe3
- MISChttps://git.kernel.org/stable/c/2d86aeb46d5f69c704065a8c69822582787272a1
- MISChttps://git.kernel.org/stable/c/80df409e1a483676826a6c66e693dba6ac507751