gpu: host1x: Avoid stack over-read in debug output helpers

Summary

In the Linux kernel, the following vulnerability has been resolved: gpu: host1x: Avoid stack over-read in debug output helpers host1x_debug_output() and host1x_debug_cont() used vsnprintf(), which returns the length the formatted string would have reached with an unbounded buffer. That return value was passed straight to o->fn as the number of bytes to emit. This could cause a read past end of the output buffer if a call to host1x_debug_* produced a string longer than 256 bytes. This only affected the debugfs files as the printk debug sink ignores the number of bytes. In practice, this is very unlikely to occur. Fix by switching to vscnprintf(), which returns the number of bytes actually written.

Timeline

1. Sep 17, 2026, 4:10 PM UTCCVE published
2. Oct 19, 2026, 9:04 AM UTCRecord last updated

Affected versions

• Linux Linux

  From 6236451d83a720072053855fa63d51934024a707 · fixed in d7a560dc912756fd8b39b28b10818d931e863d2d; From 6236451d83a720072053855fa63d51934024a707 · fixed in 41517c46002afd717f0f2d0975c740dd610f87fe; From 6236451d83a720072053855fa63d51934024a707 · fixed in ebab3a25a0403bcbc0c40ef77d69d23270e45547; From 6236451d83a720072053855fa63d51934024a707 · fixed in 4f9f0afdbdf513a49065207ff6b7e1d15051175a; From 6236451d83a720072053855fa63d51934024a707 · fixed in 819dd96a6571f2b12496b080e5187ba3fa897232; From 6236451d83a720072053855fa63d51934024a707 · fixed in 9ad7a6ccc7b839247663d57d3dbb4481dec492de; From 6236451d83a720072053855fa63d51934024a707 · fixed in b00290d1dc23a5ef9a0d3103aad1fe2274e86569; From 6236451d83a720072053855fa63d51934024a707 · fixed in bc17ac285fb708f22a8fa2c0ed32eceb1d37e6d6

• Linux Linux

  3.10

• KernelLinux

  From 3.10.0 · fixed in 5.10.270; From 5.11.0 · fixed in 5.15.221; From 5.16.0 · fixed in 6.1.188; From 6.2.0 · fixed in 6.6.157; From 6.7.0 · fixed in 6.12.110; From 6.13.0 · fixed in 6.18.52; From 6.19.0 · fixed in 7.2.6

References 8