um: mconsole: Fix out-of-bounds read in mconsole_log()

mconsole_parse() matches the 3-byte prefix "log", but mconsole_log()
skips strlen("log ") = 4 bytes, advancing ptr past the NUL terminator
when a client sends "log" without a trailing space.

The length then comes from req->len, the raw recvfrom() count, instead
of req->request.len, so printk() reads up to req->len - 4 bytes of
stale data from a previous request left in the static mc_request
buffer, leaking it to the kernel log.

Use req->cmd->command for the actual command length, add skip_spaces(),
use req->request.len, and guard against non-positive length.

Signed-off-by: Shengzhuo Wei <me@cherr.cc>
Link: https://patch.msgid.link/20260425-mconsole-oob-read-leak-v1-1-7d46e5892c5c@cherr.cc
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

0 files changed, 0 insertions, 0 deletions