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CVE-2021-47243

sch_cake: Fix out of bounds when parsing TCP options and header PUBLISHED

Description (CNA)

In the Linux kernel, the following vulnerability has been resolved: sch_cake: Fix out of bounds when parsing TCP options and header The TCP option parser in cake qdisc (cake_get_tcpopt and cake_tcph_may_drop) could read one byte out of bounds. When the length is 1, the execution flow gets into the loop, reads one byte of the opcode, and if the opcode is neither TCPOPT_EOL nor TCPOPT_NOP, it reads one more byte, which exceeds the length of 1. This fix is inspired by commit 9609dad263f8 ("ipv4: tcp_input: fix stack out of bounds when parsing TCP options."). v2 changes: Added doff validation in cake_get_tcphdr to avoid parsing garbage as TCP header. Although it wasn't strictly an out-of-bounds access (memory was allocated), garbage values could be read where CAKE expected the TCP header if doff was smaller than 5.

Affected (CNA)

Vendor / productVersions
Linux / Linuxaffected 8b7138814f29933898ecd31dfc83e35a30ee69f5 before 595897ef118d6fe66690c4fc5b572028c9da95b7; affected 8b7138814f29933898ecd31dfc83e35a30ee69f5 before 4cefa061fc63f4d2dff5ab4083f43857cd7a2335; affected 8b7138814f29933898ecd31dfc83e35a30ee69f5 before 3b491dd593d582ceeb27aa617600712a6bd14246; affected 8b7138814f29933898ecd31dfc83e35a30ee69f5 before 3371392c60e2685af30bd4547badd880f5df2b3f; affected 8b7138814f29933898ecd31dfc83e35a30ee69f5 before ba91c49dedbde758ba0b72f57ac90b06ddf8e548
Linux / Linuxaffected 4.19; unaffected 0 before 4.19; unaffected 4.19.196 through 4.19.*; unaffected 5.4.128 through 5.4.*; unaffected 5.10.46 through 5.10.*; unaffected 5.12.13 through 5.12.*; unaffected 5.13 through *

CWE

No CWE identifiers supplied.

References

ADP enrichment

CVE

No English description supplied.

CISA-ADP

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No references supplied.