CVE-2021-47013
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,..).
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.78%). 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: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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.78% probability · 54th 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/16d8c44be52e3650917736d45f5904384a9da834Patch
- https://git.kernel.org/stable/c/55fcdd1258faaecca74b91b88cc0921f9edd775dPatch
- https://git.kernel.org/stable/c/6d72e7c767acbbdd44ebc7d89c6690b405b32b57Patch
- https://git.kernel.org/stable/c/8c06f34785068b87e2b560534c77c163d6c6dca7Patch
- https://git.kernel.org/stable/c/9dc373f74097edd0e35f3393d6248eda8d1ba99dPatch
- https://git.kernel.org/stable/c/c7f75d11fe72913d2619f97b2334b083cd7bb955Patch
- https://git.kernel.org/stable/c/dc1b438a35773d030be0ee80d9c635c3e558a322Patch
- https://git.kernel.org/stable/c/e407495ba6788a67d1bd41714158c079e340879bPatch
- https://git.kernel.org/stable/c/16d8c44be52e3650917736d45f5904384a9da834Patch
- https://git.kernel.org/stable/c/55fcdd1258faaecca74b91b88cc0921f9edd775dPatch
- https://git.kernel.org/stable/c/6d72e7c767acbbdd44ebc7d89c6690b405b32b57Patch
- https://git.kernel.org/stable/c/8c06f34785068b87e2b560534c77c163d6c6dca7Patch
- https://git.kernel.org/stable/c/9dc373f74097edd0e35f3393d6248eda8d1ba99dPatch
- https://git.kernel.org/stable/c/c7f75d11fe72913d2619f97b2334b083cd7bb955Patch
- https://git.kernel.org/stable/c/dc1b438a35773d030be0ee80d9c635c3e558a322Patch
- https://git.kernel.org/stable/c/e407495ba6788a67d1bd41714158c079e340879bPatch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.