diff options
Diffstat (limited to 'security/security.c')
| -rw-r--r-- | security/security.c | 33 |
1 files changed, 30 insertions, 3 deletions
diff --git a/security/security.c b/security/security.c index d91c66d3956b..3b11b3b72fe2 100644 --- a/security/security.c +++ b/security/security.c @@ -20,6 +20,9 @@ #include <linux/ima.h> #include <linux/evm.h> #include <linux/fsnotify.h> +#include <linux/mman.h> +#include <linux/mount.h> +#include <linux/personality.h> #include <net/flow.h> #define MAX_LSM_EVM_XATTR 2 @@ -657,11 +660,35 @@ int security_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg) return security_ops->file_ioctl(file, cmd, arg); } -int security_mmap_file(struct file *file, unsigned long reqprot, - unsigned long prot, unsigned long flags) +int security_mmap_file(struct file *file, unsigned long prot, + unsigned long flags) { + unsigned long reqprot = prot; int ret; - + /* + * Does the application expect PROT_READ to imply PROT_EXEC? + * + * (the exception is when the underlying filesystem is noexec + * mounted, in which case we dont add PROT_EXEC.) + */ + if (!(reqprot & PROT_READ)) + goto out; + if (!(current->personality & READ_IMPLIES_EXEC)) + goto out; + if (!file) { + prot |= PROT_EXEC; + } else if (!(file->f_path.mnt->mnt_flags & MNT_NOEXEC)) { +#ifndef CONFIG_MMU + unsigned long caps = 0; + struct address_space *mapping = file->f_mapping; + if (mapping && mapping->backing_dev_info) + caps = mapping->backing_dev_info->capabilities; + if (!(caps & BDI_CAP_EXEC_MAP)) + goto out; +#endif + prot |= PROT_EXEC; + } +out: ret = security_ops->mmap_file(file, reqprot, prot, flags); if (ret) return ret; |