It is more natural to check for read-from-memory permissions in case of process_vm_readv() as PTRACE_MODE_ATTACH is equivalent to write permissions.
Signed-off-by: Alexey Dobriyan <[email protected]> --- mm/process_vm_access.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -204,7 +204,7 @@ static ssize_t process_vm_rw_core(pid_t pid, struct iov_iter *iter, goto free_proc_pages; } - mm = mm_access(task, PTRACE_MODE_ATTACH_REALCREDS); + mm = mm_access(task, vm_write ? PTRACE_MODE_ATTACH_REALCREDS : PTRACE_MODE_READ_REALCREDS); if (!mm || IS_ERR(mm)) { rc = IS_ERR(mm) ? PTR_ERR(mm) : -ESRCH; /*
