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take security_mmap_file() outside of ->mmap_sem

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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2012-05-30 17:11:23 -04:00
parent e5467859f7
commit 8b3ec6814c
5 changed files with 62 additions and 28 deletions
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7
include/linux/security.h
View file

@ -1745,8 +1745,8 @@ int security_file_permission(struct file *file, int mask);
int security_file_alloc(struct file *file);
void security_file_free(struct file *file);
int security_file_ioctl(struct file *file, unsigned int cmd, unsigned long 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);
int security_mmap_addr(unsigned long addr);
int security_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot,
unsigned long prot);
@ -2183,8 +2183,7 @@ static inline int security_file_ioctl(struct file *file, unsigned int cmd,
return 0;
}
static inline int security_mmap_file(struct file *file, unsigned long reqprot,
unsigned long prot,
static inline int security_mmap_file(struct file *file, unsigned long prot,
unsigned long flags)
{
return 0;

5
ipc/shm.c
View file

@ -1036,6 +1036,10 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
sfd->file = shp->shm_file;
sfd->vm_ops = NULL;
err = security_mmap_file(file, prot, flags);
if (err)
goto out_fput;
down_write(&current->mm->mmap_sem);
if (addr && !(shmflg & SHM_REMAP)) {
err = -EINVAL;
@ -1058,6 +1062,7 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
invalid:
up_write(&current->mm->mmap_sem);
out_fput:
fput(file);
out_nattch:

23
mm/mmap.c
View file

@ -979,7 +979,6 @@ static unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
struct inode *inode;
vm_flags_t vm_flags;
int error;
unsigned long reqprot = prot;
/*
* Does the application expect PROT_READ to imply PROT_EXEC?
@ -1105,10 +1104,6 @@ static unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
if (error)
return error;
error = security_mmap_file(file, reqprot, prot, flags);
if (error)
return error;
return mmap_region(file, addr, len, flags, vm_flags, pgoff);
}
@ -1130,9 +1125,12 @@ unsigned long vm_mmap(struct file *file, unsigned long addr,
unsigned long ret;
struct mm_struct *mm = current->mm;
down_write(&mm->mmap_sem);
ret = do_mmap(file, addr, len, prot, flag, offset);
up_write(&mm->mmap_sem);
ret = security_mmap_file(file, prot, flag);
if (!ret) {
down_write(&mm->mmap_sem);
ret = do_mmap(file, addr, len, prot, flag, offset);
up_write(&mm->mmap_sem);
}
return ret;
}
EXPORT_SYMBOL(vm_mmap);
@ -1168,9 +1166,12 @@ SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
down_write(&current->mm->mmap_sem);
retval = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
up_write(&current->mm->mmap_sem);
retval = security_mmap_file(file, prot, flags);
if (!retval) {
down_write(&current->mm->mmap_sem);
retval = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
up_write(&current->mm->mmap_sem);
}
if (file)
fput(file);

22
mm/nommu.c
View file

@ -889,7 +889,6 @@ static int validate_mmap_request(struct file *file,
unsigned long *_capabilities)
{
unsigned long capabilities, rlen;
unsigned long reqprot = prot;
int ret;
/* do the simple checks first */
@ -1048,9 +1047,6 @@ static int validate_mmap_request(struct file *file,
/* allow the security API to have its say */
ret = security_mmap_addr(addr);
if (ret < 0)
return ret;
ret = security_mmap_file(file, reqprot, prot, flags);
if (ret < 0)
return ret;
@ -1492,9 +1488,12 @@ unsigned long vm_mmap(struct file *file, unsigned long addr,
unsigned long ret;
struct mm_struct *mm = current->mm;
down_write(&mm->mmap_sem);
ret = do_mmap(file, addr, len, prot, flag, offset);
up_write(&mm->mmap_sem);
ret = security_mmap_file(file, prot, flag);
if (!ret) {
down_write(&mm->mmap_sem);
ret = do_mmap(file, addr, len, prot, flag, offset);
up_write(&mm->mmap_sem);
}
return ret;
}
EXPORT_SYMBOL(vm_mmap);
@ -1515,9 +1514,12 @@ SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
down_write(&current->mm->mmap_sem);
retval = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
up_write(&current->mm->mmap_sem);
ret = security_mmap_file(file, prot, flags);
if (!ret) {
down_write(&current->mm->mmap_sem);
retval = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
up_write(&current->mm->mmap_sem);
}
if (file)
fput(file);

33
security/security.c
View file

@ -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;