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Javi Merino
bb03169bcb
When built with ASAN, "xl dmesg" crashes in the "printf("%s", line)"
call in main_dmesg(). ASAN reports a heap buffer overflow: an
off-by-one access to cr->buffer.
The readconsole sysctl copies up to count characters into the buffer,
but it does not add a null character at the end. Despite the
documentation of libxl_xen_console_read_line(), line_r is not
nul-terminated if 16384 characters were copied to the buffer.
Fix this by asking xc_readconsolering() to fill the buffer up to size
- 1. As the number of characters in the buffer is only needed in
libxl_xen_console_read_line(), make it a local variable there instead
of part of the libxl__xen_console_reader struct.
Fixes: 4024bae739 ("xl: Add subcommand 'xl dmesg'")
Reported-by: Edwin Török <edwin.torok@cloud.com>
Signed-off-by: Javi Merino <javi.merino@cloud.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>