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Tracker / CVE-2021-47013

CVE-2021-47013

Critical 9.8

In the Linux kernel, the following vulnerability has been resolved: net:emac/emac-mac: Fix a use after free in emac_mac_tx_buf_send In emac_mac_tx_buf_send, it calls emac_tx_fill_tpd(..,skb,..). If some error happens in emac_tx_fill_tpd(), the skb will be freed via dev_kfree_skb(skb) in error branch of emac_tx_fill_tpd(). But the freed skb is still used via skb->len by netdev_sent_queue(,skb->len). As i observed that emac_tx_fill_tpd() haven't modified the value of skb->len, thus my patch assigns skb->len to 'len' before the possible free and use 'len' instead of skb->len later.

Affected products and versions

linux linux_kernel · 4.10 → 4.14.233
linux linux_kernel · 4.15 → 4.19.191
linux linux_kernel · 4.20 → 5.4.119
linux linux_kernel · 4.9 → 4.9.269
linux linux_kernel · 5.11 → 5.11.21
linux linux_kernel · 5.12 → 5.12.4
linux linux_kernel · 5.5 → 5.10.37

Analysis

This page is not indexable yet.Until it carries original analysis — what it actually exposes, how to check in two minutes whether a system was touched, what to do if it was — the page stays noindex. The database decides that, not the template.

References