serial: sc16is7xx: fix TX fifo corruption
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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 6.6.160, 6.2, 6.8, 6.10.5
- 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: partial
Summary
In the Linux kernel, the following vulnerability has been resolved: serial: sc16is7xx: fix TX fifo corruption Sometimes, when a packet is received on channel A at almost the same time as a packet is about to be transmitted on channel B, we observe with a logic analyzer that the received packet on channel A is transmitted on channel B. In other words, the Tx buffer data on channel B is corrupted with data from channel A. The problem appeared since commit 4409df5866b7 ("serial: sc16is7xx: change EFR lock to operate on each channels"), which changed the EFR locking to operate on each channel instead of chip-wise. This commit has introduced a regression, because the EFR lock is used not only to protect the EFR registers access, but also, in a very obscure and undocumented way, to protect access to the data buffer, which is shared by the Tx and Rx handlers, but also by each channel of the IC. Fix this regression first by switching to kfifo_out_linear_ptr() in sc16is7xx_handle_tx() to eliminate the need for a shared Rx/Tx buffer. Secondly, replace the chip-wise Rx buffer with a separate Rx buffer for each channel.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- Linux Linux
From 9879e1bec3c0f077427dd0d258c80c63ce9babdf · fixed in 2a0ba376cdf729b5c66226c65c6c7cf9de744d52; From 4409df5866b7ff7686ba27e449ca97a92ee063c9 · fixed in 09cfe05e9907f3276887a20e267cc40e202f4fdd; From 4409df5866b7ff7686ba27e449ca97a92ee063c9 · fixed in 133f4c00b8b2bfcacead9b81e7e8edfceb4b06c4; From 6.6.15 · fixed in 6.6.160; From 6.1.76 · fixed in 6.2; From 6.7.3 · fixed in 6.8
- Linux Linux
6.8
- KernelLinux
fixed in 6.6.160; From 6.7.0 · fixed in 6.10.5