[PATCH] avoid multiplication overflows and signedness issues for max_fds
Limit sysctl_nr_open - we don't want ->max_fds to exceed MAX_INT and
we don't want size calculation for ->fd[] to overflow.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/file.c b/fs/file.c
index 0f705c7c..7b3887e 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -26,6 +26,8 @@
};
int sysctl_nr_open __read_mostly = 1024*1024;
+int sysctl_nr_open_min = BITS_PER_LONG;
+int sysctl_nr_open_max = 1024 * 1024; /* raised later */
/*
* We use this list to defer free fdtables that have vmalloced
@@ -405,6 +407,8 @@
int i;
for_each_possible_cpu(i)
fdtable_defer_list_init(i);
+ sysctl_nr_open_max = min((size_t)INT_MAX, ~(size_t)0/sizeof(void *)) &
+ -BITS_PER_LONG;
}
struct files_struct init_files = {
