riscv: trace: fix snapshot deadlock with sbi ecall
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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 6.11, 6.12.114, 6.18.10
- 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
Summary
In the Linux kernel, the following vulnerability has been resolved: riscv: trace: fix snapshot deadlock with sbi ecall If sbi_ecall.c's functions are traceable, echo "__sbi_ecall:snapshot" > /sys/kernel/tracing/set_ftrace_filter may get the kernel into a deadlock. (Functions in sbi_ecall.c are excluded from tracing if CONFIG_RISCV_ALTERNATIVE_EARLY is set.) __sbi_ecall triggers a snapshot of the ringbuffer. The snapshot code raises an IPI interrupt, which results in another call to __sbi_ecall and another snapshot... All it takes to get into this endless loop is one initial __sbi_ecall. On RISC-V systems without SSTC extension, the clock events in timer-riscv.c issue periodic sbi ecalls, making the problem easy to trigger. Always exclude the sbi_ecall.c functions from tracing to fix the potential deadlock. sbi ecalls can easiliy be logged via trace events, excluding ecall functions from function tracing is not a big limitation.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From 1ff95eb2bebda50c4c5406caaf201e0fcb24cc8f · fixed in f8b8ec0ddde74066d4452a7a961da544f193e00f; From 1ff95eb2bebda50c4c5406caaf201e0fcb24cc8f · fixed in b1f8285bc8e3508c1fde23b5205f1270215d4984; From 1ff95eb2bebda50c4c5406caaf201e0fcb24cc8f · fixed in b0d7f5f0c9f05f1b6d4ee7110f15bef9c11f9df0; From 6.10.10 · fixed in 6.11
- Linux Linux
6.11
- KernelLinux
From 6.11.0 · fixed in 6.12.114; From 6.13.0 · fixed in 6.18.10