| Message ID | 20221207154939.2532830-7-jeffxu@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/memfd: introduce MFD_NOEXEC_SEAL and MFD_EXEC | expand |
On Wed, Dec 07, 2022 at 03:49:39PM +0000, jeffxu@chromium.org wrote: > From: Jeff Xu <jeffxu@google.com> > > The new security_memfd_create allows lsm to check flags of > memfd_create. > > The security by default system (such as chromeos) can use this > to implement system wide lsm to allow only non-executable memfd > being created. > > Signed-off-by: Jeff Xu <jeffxu@google.com> > Reported-by: kernel test robot <lkp@intel.com> > --- > include/linux/lsm_hook_defs.h | 1 + > include/linux/lsm_hooks.h | 4 ++++ > include/linux/security.h | 6 ++++++ > mm/memfd.c | 5 +++++ > security/security.c | 13 +++++++++++++ > 5 files changed, 29 insertions(+) > > diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h > index ec119da1d89b..fd40840927c8 100644 > --- a/include/linux/lsm_hook_defs.h > +++ b/include/linux/lsm_hook_defs.h > @@ -164,6 +164,7 @@ LSM_HOOK(int, 0, file_alloc_security, struct file *file) > LSM_HOOK(void, LSM_RET_VOID, file_free_security, struct file *file) > LSM_HOOK(int, 0, file_ioctl, struct file *file, unsigned int cmd, > unsigned long arg) > +LSM_HOOK(int, 0, memfd_create, char *name, unsigned int flags) > LSM_HOOK(int, 0, mmap_addr, unsigned long addr) > LSM_HOOK(int, 0, mmap_file, struct file *file, unsigned long reqprot, > unsigned long prot, unsigned long flags) > diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h > index 4ec80b96c22e..5a18a6552278 100644 > --- a/include/linux/lsm_hooks.h > +++ b/include/linux/lsm_hooks.h > @@ -543,6 +543,10 @@ > * simple integer value. When @arg represents a user space pointer, it > * should never be used by the security module. > * Return 0 if permission is granted. > + * @memfd_create: > + * @name is the name of memfd file. > + * @flags is the flags used in memfd_create. > + * Return 0 if permission is granted. > * @mmap_addr : > * Check permissions for a mmap operation at @addr. > * @addr contains virtual address that will be used for the operation. > diff --git a/include/linux/security.h b/include/linux/security.h > index ca1b7109c0db..5b87a780822a 100644 > --- a/include/linux/security.h > +++ b/include/linux/security.h > @@ -384,6 +384,7 @@ 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_memfd_create(char *name, unsigned int flags); > int security_mmap_file(struct file *file, unsigned long prot, > unsigned long flags); > int security_mmap_addr(unsigned long addr); > @@ -963,6 +964,11 @@ static inline int security_file_ioctl(struct file *file, unsigned int cmd, > return 0; > } > > +static inline int security_memfd_create(char *name, unsigned int flags) > +{ > + return 0; > +} > + > static inline int security_mmap_file(struct file *file, unsigned long prot, > unsigned long flags) > { > diff --git a/mm/memfd.c b/mm/memfd.c > index 92f0a5765f7c..f04ed5f0474f 100644 > --- a/mm/memfd.c > +++ b/mm/memfd.c > @@ -356,6 +356,11 @@ SYSCALL_DEFINE2(memfd_create, > goto err_name; > } > > + /* security hook for memfd_create */ > + error = security_memfd_create(name, flags); > + if (error) > + return error; > + > if (flags & MFD_HUGETLB) { > file = hugetlb_file_setup(name, 0, VM_NORESERVE, > HUGETLB_ANONHUGE_INODE, > diff --git a/security/security.c b/security/security.c > index 79d82cb6e469..5c018e080923 100644 > --- a/security/security.c > +++ b/security/security.c > @@ -1010,6 +1010,19 @@ int security_sb_clone_mnt_opts(const struct super_block *oldsb, > } > EXPORT_SYMBOL(security_sb_clone_mnt_opts); > > +int security_add_mnt_opt(const char *option, const char *val, int len, > + void **mnt_opts) > +{ > + return call_int_hook(sb_add_mnt_opt, -EINVAL, > + option, val, len, mnt_opts); > +} > +EXPORT_SYMBOL(security_add_mnt_opt); I think security_add_mnt_opt() isn't supposed to be in here. :) > + > +int security_memfd_create(char *name, unsigned int flags) > +{ > + return call_int_hook(memfd_create, 0, name, flags); > +} > + > int security_move_mount(const struct path *from_path, const struct path *to_path) > { > return call_int_hook(move_mount, 0, from_path, to_path); > -- > 2.39.0.rc0.267.gcb52ba06e7-goog > Otherwise looks good. Thanks! -Kees
On Wed, Dec 07, 2022 at 03:49:39PM +0000, jeffxu@chromium.org wrote: > From: Jeff Xu <jeffxu@google.com> > > The new security_memfd_create allows lsm to check flags of > memfd_create. > > The security by default system (such as chromeos) can use this > to implement system wide lsm to allow only non-executable memfd > being created. > > Signed-off-by: Jeff Xu <jeffxu@google.com> > Reported-by: kernel test robot <lkp@intel.com> Oh, btw, please CC linux-security-module@vger.kernel.org when adding new hooks. (I've added the CC here.) -Kees > --- > include/linux/lsm_hook_defs.h | 1 + > include/linux/lsm_hooks.h | 4 ++++ > include/linux/security.h | 6 ++++++ > mm/memfd.c | 5 +++++ > security/security.c | 13 +++++++++++++ > 5 files changed, 29 insertions(+) > > diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h > index ec119da1d89b..fd40840927c8 100644 > --- a/include/linux/lsm_hook_defs.h > +++ b/include/linux/lsm_hook_defs.h > @@ -164,6 +164,7 @@ LSM_HOOK(int, 0, file_alloc_security, struct file *file) > LSM_HOOK(void, LSM_RET_VOID, file_free_security, struct file *file) > LSM_HOOK(int, 0, file_ioctl, struct file *file, unsigned int cmd, > unsigned long arg) > +LSM_HOOK(int, 0, memfd_create, char *name, unsigned int flags) > LSM_HOOK(int, 0, mmap_addr, unsigned long addr) > LSM_HOOK(int, 0, mmap_file, struct file *file, unsigned long reqprot, > unsigned long prot, unsigned long flags) > diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h > index 4ec80b96c22e..5a18a6552278 100644 > --- a/include/linux/lsm_hooks.h > +++ b/include/linux/lsm_hooks.h > @@ -543,6 +543,10 @@ > * simple integer value. When @arg represents a user space pointer, it > * should never be used by the security module. > * Return 0 if permission is granted. > + * @memfd_create: > + * @name is the name of memfd file. > + * @flags is the flags used in memfd_create. > + * Return 0 if permission is granted. > * @mmap_addr : > * Check permissions for a mmap operation at @addr. > * @addr contains virtual address that will be used for the operation. > diff --git a/include/linux/security.h b/include/linux/security.h > index ca1b7109c0db..5b87a780822a 100644 > --- a/include/linux/security.h > +++ b/include/linux/security.h > @@ -384,6 +384,7 @@ 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_memfd_create(char *name, unsigned int flags); > int security_mmap_file(struct file *file, unsigned long prot, > unsigned long flags); > int security_mmap_addr(unsigned long addr); > @@ -963,6 +964,11 @@ static inline int security_file_ioctl(struct file *file, unsigned int cmd, > return 0; > } > > +static inline int security_memfd_create(char *name, unsigned int flags) > +{ > + return 0; > +} > + > static inline int security_mmap_file(struct file *file, unsigned long prot, > unsigned long flags) > { > diff --git a/mm/memfd.c b/mm/memfd.c > index 92f0a5765f7c..f04ed5f0474f 100644 > --- a/mm/memfd.c > +++ b/mm/memfd.c > @@ -356,6 +356,11 @@ SYSCALL_DEFINE2(memfd_create, > goto err_name; > } > > + /* security hook for memfd_create */ > + error = security_memfd_create(name, flags); > + if (error) > + return error; > + > if (flags & MFD_HUGETLB) { > file = hugetlb_file_setup(name, 0, VM_NORESERVE, > HUGETLB_ANONHUGE_INODE, > diff --git a/security/security.c b/security/security.c > index 79d82cb6e469..5c018e080923 100644 > --- a/security/security.c > +++ b/security/security.c > @@ -1010,6 +1010,19 @@ int security_sb_clone_mnt_opts(const struct super_block *oldsb, > } > EXPORT_SYMBOL(security_sb_clone_mnt_opts); > > +int security_add_mnt_opt(const char *option, const char *val, int len, > + void **mnt_opts) > +{ > + return call_int_hook(sb_add_mnt_opt, -EINVAL, > + option, val, len, mnt_opts); > +} > +EXPORT_SYMBOL(security_add_mnt_opt); > + > +int security_memfd_create(char *name, unsigned int flags) > +{ > + return call_int_hook(memfd_create, 0, name, flags); > +} > + > int security_move_mount(const struct path *from_path, const struct path *to_path) > { > return call_int_hook(move_mount, 0, from_path, to_path); > -- > 2.39.0.rc0.267.gcb52ba06e7-goog >
diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index ec119da1d89b..fd40840927c8 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -164,6 +164,7 @@ LSM_HOOK(int, 0, file_alloc_security, struct file *file) LSM_HOOK(void, LSM_RET_VOID, file_free_security, struct file *file) LSM_HOOK(int, 0, file_ioctl, struct file *file, unsigned int cmd, unsigned long arg) +LSM_HOOK(int, 0, memfd_create, char *name, unsigned int flags) LSM_HOOK(int, 0, mmap_addr, unsigned long addr) LSM_HOOK(int, 0, mmap_file, struct file *file, unsigned long reqprot, unsigned long prot, unsigned long flags) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 4ec80b96c22e..5a18a6552278 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -543,6 +543,10 @@ * simple integer value. When @arg represents a user space pointer, it * should never be used by the security module. * Return 0 if permission is granted. + * @memfd_create: + * @name is the name of memfd file. + * @flags is the flags used in memfd_create. + * Return 0 if permission is granted. * @mmap_addr : * Check permissions for a mmap operation at @addr. * @addr contains virtual address that will be used for the operation. diff --git a/include/linux/security.h b/include/linux/security.h index ca1b7109c0db..5b87a780822a 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -384,6 +384,7 @@ 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_memfd_create(char *name, unsigned int flags); int security_mmap_file(struct file *file, unsigned long prot, unsigned long flags); int security_mmap_addr(unsigned long addr); @@ -963,6 +964,11 @@ static inline int security_file_ioctl(struct file *file, unsigned int cmd, return 0; } +static inline int security_memfd_create(char *name, unsigned int flags) +{ + return 0; +} + static inline int security_mmap_file(struct file *file, unsigned long prot, unsigned long flags) { diff --git a/mm/memfd.c b/mm/memfd.c index 92f0a5765f7c..f04ed5f0474f 100644 --- a/mm/memfd.c +++ b/mm/memfd.c @@ -356,6 +356,11 @@ SYSCALL_DEFINE2(memfd_create, goto err_name; } + /* security hook for memfd_create */ + error = security_memfd_create(name, flags); + if (error) + return error; + if (flags & MFD_HUGETLB) { file = hugetlb_file_setup(name, 0, VM_NORESERVE, HUGETLB_ANONHUGE_INODE, diff --git a/security/security.c b/security/security.c index 79d82cb6e469..5c018e080923 100644 --- a/security/security.c +++ b/security/security.c @@ -1010,6 +1010,19 @@ int security_sb_clone_mnt_opts(const struct super_block *oldsb, } EXPORT_SYMBOL(security_sb_clone_mnt_opts); +int security_add_mnt_opt(const char *option, const char *val, int len, + void **mnt_opts) +{ + return call_int_hook(sb_add_mnt_opt, -EINVAL, + option, val, len, mnt_opts); +} +EXPORT_SYMBOL(security_add_mnt_opt); + +int security_memfd_create(char *name, unsigned int flags) +{ + return call_int_hook(memfd_create, 0, name, flags); +} + int security_move_mount(const struct path *from_path, const struct path *to_path) { return call_int_hook(move_mount, 0, from_path, to_path);