bus: mhi: host: Detect events pointing to unexpected TREs
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 5.15.190, 6.1.149, 6.6.103, 6.12.44, 6.16.4
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: total
Summary
In the Linux kernel, the following vulnerability has been resolved: bus: mhi: host: Detect events pointing to unexpected TREs When a remote device sends a completion event to the host, it contains a pointer to the consumed TRE. The host uses this pointer to process all of the TREs between it and the host's local copy of the ring's read pointer. This works when processing completion for chained transactions, but can lead to nasty results if the device sends an event for a single-element transaction with a read pointer that is multiple elements ahead of the host's read pointer. For instance, if the host accesses an event ring while the device is updating it, the pointer inside of the event might still point to an old TRE. If the host uses the channel's xfer_cb() to directly free the buffer pointed to by the TRE, the buffer will be double-freed. This behavior was observed on an ep that used upstream EP stack without 'commit 6f18d174b73d ("bus: mhi: ep: Update read pointer only after buffer is written")'. Where the device updated the events ring pointer before updating the event contents, so it left a window where the host was able to access the stale data the event pointed to, before the device had the chance to update them. The usual pattern was that the host received an event pointing to a TRE that is not immediately after the last processed one, so it got treated as if it was a chained transaction, processing all of the TREs in between the two read pointers. This commit aims to harden the host by ensuring transactions where the event points to a TRE that isn't local_rp + 1 are chained. [mani: added stable tag and reworded commit message]
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: total
- Record last updated
Affected versions
- Linux Linux
From 1d3173a3bae7039b765a0956e3e4bf846dbaacb8 · fixed in 7b3f0e3b60c27f4fcb69927d84987e5fd6240530; From 1d3173a3bae7039b765a0956e3e4bf846dbaacb8 · fixed in 4079c6c59705b96285219b9efc63cab870d757b7; From 1d3173a3bae7039b765a0956e3e4bf846dbaacb8 · fixed in 5e17429679a8545afe438ce7a82a13a54e8ceabb; From 1d3173a3bae7039b765a0956e3e4bf846dbaacb8 · fixed in 2ec99b922f4661521927eeada76f431eebfbabc4; From 1d3173a3bae7039b765a0956e3e4bf846dbaacb8 · fixed in 44e1a079e18f78d6594a715b0c6d7e18c656f7b9; From 1d3173a3bae7039b765a0956e3e4bf846dbaacb8 · fixed in 5bd398e20f0833ae8a1267d4f343591a2dd20185
- Linux Linux
5.7
- KernelLinux
From 5.7.0 · fixed in 5.15.190; From 5.16.0 · fixed in 6.1.149; From 6.2.0 · fixed in 6.6.103; From 6.7.0 · fixed in 6.12.44; From 6.13.0 · fixed in 6.16.4