| Message ID | 20230831104136.903180-16-roberto.sassu@huaweicloud.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Paul Moore |
| Headers | show |
| Series | security: Move IMA and EVM to the LSM infrastructure | expand |
On 8/31/2023 3:41 AM, Roberto Sassu wrote: > From: Roberto Sassu <roberto.sassu@huawei.com> > > In preparation for moving IMA and EVM to the LSM infrastructure, introduce > the file_pre_free_security hook. Repeat of new LSM hook general comment: Would you please include some explanation of how an LSM would use this hook? You might start with a description of how it is used in IMA/EVM, and why that could be generally useful. > > Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> > Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> > --- > fs/file_table.c | 1 + > include/linux/lsm_hook_defs.h | 1 + > include/linux/security.h | 4 ++++ > security/security.c | 11 +++++++++++ > 4 files changed, 17 insertions(+) > > diff --git a/fs/file_table.c b/fs/file_table.c > index fc7d677ff5ad..964e24120684 100644 > --- a/fs/file_table.c > +++ b/fs/file_table.c > @@ -375,6 +375,7 @@ static void __fput(struct file *file) > eventpoll_release(file); > locks_remove_file(file); > > + security_file_pre_free(file); > ima_file_free(file); > if (unlikely(file->f_flags & FASYNC)) { > if (file->f_op->fasync) > diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h > index 60ed33f0c80d..797f51da3f7d 100644 > --- a/include/linux/lsm_hook_defs.h > +++ b/include/linux/lsm_hook_defs.h > @@ -172,6 +172,7 @@ LSM_HOOK(int, 0, kernfs_init_security, struct kernfs_node *kn_dir, > struct kernfs_node *kn) > LSM_HOOK(int, 0, file_permission, struct file *file, int mask) > LSM_HOOK(int, 0, file_alloc_security, struct file *file) > +LSM_HOOK(void, LSM_RET_VOID, file_pre_free_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) > diff --git a/include/linux/security.h b/include/linux/security.h > index a0f16511c059..7871009d59ae 100644 > --- a/include/linux/security.h > +++ b/include/linux/security.h > @@ -389,6 +389,7 @@ int security_kernfs_init_security(struct kernfs_node *kn_dir, > struct kernfs_node *kn); > int security_file_permission(struct file *file, int mask); > int security_file_alloc(struct file *file); > +void security_file_pre_free(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 prot, > @@ -985,6 +986,9 @@ static inline int security_file_alloc(struct file *file) > return 0; > } > > +static inline void security_file_pre_free(struct file *file) > +{ } > + > static inline void security_file_free(struct file *file) > { } > > diff --git a/security/security.c b/security/security.c > index 3e0078b51e46..3e648aa9292c 100644 > --- a/security/security.c > +++ b/security/security.c > @@ -2626,6 +2626,17 @@ int security_file_alloc(struct file *file) > return rc; > } > > +/** > + * security_file_pre_free() - Perform actions before freeing a file's LSM blob > + * @file: the file > + * > + * Perform actions before the file descriptor is freed. > + */ > +void security_file_pre_free(struct file *file) > +{ > + call_void_hook(file_pre_free_security, file); > +} > + > /** > * security_file_free() - Free a file's LSM blob > * @file: the file
diff --git a/fs/file_table.c b/fs/file_table.c index fc7d677ff5ad..964e24120684 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -375,6 +375,7 @@ static void __fput(struct file *file) eventpoll_release(file); locks_remove_file(file); + security_file_pre_free(file); ima_file_free(file); if (unlikely(file->f_flags & FASYNC)) { if (file->f_op->fasync) diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 60ed33f0c80d..797f51da3f7d 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -172,6 +172,7 @@ LSM_HOOK(int, 0, kernfs_init_security, struct kernfs_node *kn_dir, struct kernfs_node *kn) LSM_HOOK(int, 0, file_permission, struct file *file, int mask) LSM_HOOK(int, 0, file_alloc_security, struct file *file) +LSM_HOOK(void, LSM_RET_VOID, file_pre_free_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) diff --git a/include/linux/security.h b/include/linux/security.h index a0f16511c059..7871009d59ae 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -389,6 +389,7 @@ int security_kernfs_init_security(struct kernfs_node *kn_dir, struct kernfs_node *kn); int security_file_permission(struct file *file, int mask); int security_file_alloc(struct file *file); +void security_file_pre_free(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 prot, @@ -985,6 +986,9 @@ static inline int security_file_alloc(struct file *file) return 0; } +static inline void security_file_pre_free(struct file *file) +{ } + static inline void security_file_free(struct file *file) { } diff --git a/security/security.c b/security/security.c index 3e0078b51e46..3e648aa9292c 100644 --- a/security/security.c +++ b/security/security.c @@ -2626,6 +2626,17 @@ int security_file_alloc(struct file *file) return rc; } +/** + * security_file_pre_free() - Perform actions before freeing a file's LSM blob + * @file: the file + * + * Perform actions before the file descriptor is freed. + */ +void security_file_pre_free(struct file *file) +{ + call_void_hook(file_pre_free_security, file); +} + /** * security_file_free() - Free a file's LSM blob * @file: the file