Several functions in selinuxfs.c allocate temporary buffers using __get_free_page() or get_zeroed_page().
These buffers are used either to store a string generated by snprintf() (in sel_make_bools()) or to copy data from user (sel_read_avc_hash_stats() and sel_read_sidtab_hash_stats()). Such usage does not require struct page access and it is better to allocate these buffers with kzalloc()/kmalloc() that provide better scalability and more debugging possibilities. Replace use of get_zeroed_page() with kzalloc() and usage of __get_free_page() with kmalloc(). Link: https://lore.kernel.org/all/[email protected] Signed-off-by: Mike Rapoport (Microsoft) <[email protected]> --- security/selinux/selinuxfs.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c index 25ca7d714014..e7b884eedf80 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -1244,7 +1244,7 @@ static int sel_make_bools(struct selinux_policy *newpolicy, struct dentry *bool_ char **names, *page; u32 i, num; - page = (char *)get_zeroed_page(GFP_KERNEL); + page = kzalloc(PAGE_SIZE, GFP_KERNEL); if (!page) return -ENOMEM; @@ -1290,7 +1290,7 @@ static int sel_make_bools(struct selinux_policy *newpolicy, struct dentry *bool_ ret = sel_attach_file(bool_dir, names[i], inode); } out: - free_page((unsigned long)page); + kfree(page); return ret; } @@ -1349,14 +1349,14 @@ static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf, char *page; ssize_t length; - page = (char *)__get_free_page(GFP_KERNEL); + page = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!page) return -ENOMEM; length = avc_get_hash_stats(page); if (length >= 0) length = simple_read_from_buffer(buf, count, ppos, page, length); - free_page((unsigned long)page); + kfree(page); return length; } @@ -1367,7 +1367,7 @@ static ssize_t sel_read_sidtab_hash_stats(struct file *filp, char __user *buf, char *page; ssize_t length; - page = (char *)__get_free_page(GFP_KERNEL); + page = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!page) return -ENOMEM; @@ -1375,7 +1375,7 @@ static ssize_t sel_read_sidtab_hash_stats(struct file *filp, char __user *buf, if (length >= 0) length = simple_read_from_buffer(buf, count, ppos, page, length); - free_page((unsigned long)page); + kfree(page); return length; } -- 2.53.0
