Phil Auld d10d1e9d9f drivers/base: Fix unsigned comparison to -1 in CPUMAP_FILE_MAX_BYTES
commit d7f06bdd6ee87fbefa05af5f57361d85e7715b11 upstream.

As PAGE_SIZE is unsigned long, -1 > PAGE_SIZE when NR_CPUS <= 3.
This leads to very large file sizes:

topology$ ls -l
total 0
-r--r--r-- 1 root root 18446744073709551615 Sep  5 11:59 core_cpus
-r--r--r-- 1 root root                 4096 Sep  5 11:59 core_cpus_list
-r--r--r-- 1 root root                 4096 Sep  5 10:58 core_id
-r--r--r-- 1 root root 18446744073709551615 Sep  5 10:10 core_siblings
-r--r--r-- 1 root root                 4096 Sep  5 11:59 core_siblings_list
-r--r--r-- 1 root root 18446744073709551615 Sep  5 11:59 die_cpus
-r--r--r-- 1 root root                 4096 Sep  5 11:59 die_cpus_list
-r--r--r-- 1 root root                 4096 Sep  5 11:59 die_id
-r--r--r-- 1 root root 18446744073709551615 Sep  5 11:59 package_cpus
-r--r--r-- 1 root root                 4096 Sep  5 11:59 package_cpus_list
-r--r--r-- 1 root root                 4096 Sep  5 10:58 physical_package_id
-r--r--r-- 1 root root 18446744073709551615 Sep  5 10:10 thread_siblings
-r--r--r-- 1 root root                 4096 Sep  5 11:59 thread_siblings_list

Adjust the inequality to catch the case when NR_CPUS is configured
to a small value.

Fixes: 7ee951acd31a ("drivers/base: fix userspace break from using bin_attributes for cpumap and cpulist")
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: stable@vger.kernel.org
Cc: feng xiangjun <fengxj325@gmail.com>
Reported-by: feng xiangjun <fengxj325@gmail.com>
Signed-off-by: Phil Auld <pauld@redhat.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Link: https://lore.kernel.org/r/20220906203542.1796629-1-pauld@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-28 11:11:40 +02:00
2021-10-18 20:22:03 -10:00
2022-09-23 14:15:52 +02:00

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