| Message ID | 20240805-remove-cred-transfer-v2-2-a2aa1d45e6b8@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | get rid of cred_transfer | expand |
On Mon Aug 5, 2024 at 2:54 PM EEST, Jann Horn wrote: > Now that they're unused thanks to the preceding commit, remove > cred_alloc_blank(), security_transfer_creds(), and the corresponding LSM > hook implementations. > > Signed-off-by: Jann Horn <jannh@google.com> > --- > include/linux/cred.h | 1 - > include/linux/lsm_hook_defs.h | 3 --- > include/linux/security.h | 12 ------------ > kernel/cred.c | 23 ----------------------- > security/apparmor/lsm.c | 19 ------------------- > security/landlock/cred.c | 11 ++--------- > security/security.c | 35 ----------------------------------- > security/selinux/hooks.c | 12 ------------ > security/smack/smack_lsm.c | 32 -------------------------------- > 9 files changed, 2 insertions(+), 146 deletions(-) > > diff --git a/include/linux/cred.h b/include/linux/cred.h > index 2976f534a7a3..54b5105d4cd5 100644 > --- a/include/linux/cred.h > +++ b/include/linux/cred.h > @@ -147,13 +147,12 @@ struct cred { > } __randomize_layout; > > extern void __put_cred(struct cred *); > extern void exit_creds(struct task_struct *); > extern int copy_creds(struct task_struct *, unsigned long); > extern const struct cred *get_task_cred(struct task_struct *); > -extern struct cred *cred_alloc_blank(void); > extern struct cred *prepare_creds(void); > extern struct cred *prepare_exec_creds(void); > extern int commit_creds(struct cred *); > extern void abort_creds(struct cred *); > extern const struct cred *override_creds(const struct cred *); > extern void revert_creds(const struct cred *); > diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h > index 855db460e08b..1d75075cb607 100644 > --- a/include/linux/lsm_hook_defs.h > +++ b/include/linux/lsm_hook_defs.h > @@ -204,18 +204,15 @@ LSM_HOOK(int, 0, file_receive, struct file *file) > LSM_HOOK(int, 0, file_open, struct file *file) > LSM_HOOK(int, 0, file_post_open, struct file *file, int mask) > LSM_HOOK(int, 0, file_truncate, struct file *file) > LSM_HOOK(int, 0, task_alloc, struct task_struct *task, > unsigned long clone_flags) > LSM_HOOK(void, LSM_RET_VOID, task_free, struct task_struct *task) > -LSM_HOOK(int, 0, cred_alloc_blank, struct cred *cred, gfp_t gfp) > LSM_HOOK(void, LSM_RET_VOID, cred_free, struct cred *cred) > LSM_HOOK(int, 0, cred_prepare, struct cred *new, const struct cred *old, > gfp_t gfp) > -LSM_HOOK(void, LSM_RET_VOID, cred_transfer, struct cred *new, > - const struct cred *old) > LSM_HOOK(void, LSM_RET_VOID, cred_getsecid, const struct cred *c, u32 *secid) > LSM_HOOK(int, 0, kernel_act_as, struct cred *new, u32 secid) > LSM_HOOK(int, 0, kernel_create_files_as, struct cred *new, struct inode *inode) > LSM_HOOK(int, 0, kernel_module_request, char *kmod_name) > LSM_HOOK(int, 0, kernel_load_data, enum kernel_load_data_id id, bool contents) > LSM_HOOK(int, 0, kernel_post_load_data, char *buf, loff_t size, > diff --git a/include/linux/security.h b/include/linux/security.h > index 1390f1efb4f0..a366c2a03f55 100644 > --- a/include/linux/security.h > +++ b/include/linux/security.h > @@ -421,16 +421,14 @@ int security_file_send_sigiotask(struct task_struct *tsk, > int security_file_receive(struct file *file); > int security_file_open(struct file *file); > int security_file_post_open(struct file *file, int mask); > int security_file_truncate(struct file *file); > int security_task_alloc(struct task_struct *task, unsigned long clone_flags); > void security_task_free(struct task_struct *task); > -int security_cred_alloc_blank(struct cred *cred, gfp_t gfp); > void security_cred_free(struct cred *cred); > int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp); > -void security_transfer_creds(struct cred *new, const struct cred *old); > void security_cred_getsecid(const struct cred *c, u32 *secid); > int security_kernel_act_as(struct cred *new, u32 secid); > int security_kernel_create_files_as(struct cred *new, struct inode *inode); > int security_kernel_module_request(char *kmod_name); > int security_kernel_load_data(enum kernel_load_data_id id, bool contents); > int security_kernel_post_load_data(char *buf, loff_t size, > @@ -1117,32 +1115,22 @@ static inline int security_task_alloc(struct task_struct *task, > return 0; > } > > static inline void security_task_free(struct task_struct *task) > { } > > -static inline int security_cred_alloc_blank(struct cred *cred, gfp_t gfp) > -{ > - return 0; > -} > - > static inline void security_cred_free(struct cred *cred) > { } > > static inline int security_prepare_creds(struct cred *new, > const struct cred *old, > gfp_t gfp) > { > return 0; > } > > -static inline void security_transfer_creds(struct cred *new, > - const struct cred *old) > -{ > -} > - > static inline void security_cred_getsecid(const struct cred *c, u32 *secid) > { > *secid = 0; > } > > static inline int security_kernel_act_as(struct cred *cred, u32 secid) > diff --git a/kernel/cred.c b/kernel/cred.c > index 075cfa7c896f..b2f6130cd6b7 100644 > --- a/kernel/cred.c > +++ b/kernel/cred.c > @@ -163,35 +163,12 @@ const struct cred *get_task_cred(struct task_struct *task) > > rcu_read_unlock(); > return cred; > } > EXPORT_SYMBOL(get_task_cred); > > -/* > - * Allocate blank credentials, such that the credentials can be filled in at a > - * later date without risk of ENOMEM. > - */ > -struct cred *cred_alloc_blank(void) > -{ > - struct cred *new; > - > - new = kmem_cache_zalloc(cred_jar, GFP_KERNEL); > - if (!new) > - return NULL; > - > - atomic_long_set(&new->usage, 1); > - if (security_cred_alloc_blank(new, GFP_KERNEL_ACCOUNT) < 0) > - goto error; > - > - return new; > - > -error: > - abort_creds(new); > - return NULL; > -} > - > /** > * prepare_creds - Prepare a new set of credentials for modification > * > * Prepare a new set of task credentials for modification. A task's creds > * shouldn't generally be modified directly, therefore this function is used to > * prepare a new copy, which the caller then modifies and then commits by > diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c > index 808060f9effb..089d53978d9e 100644 > --- a/security/apparmor/lsm.c > +++ b/security/apparmor/lsm.c > @@ -74,39 +74,22 @@ static DEFINE_PER_CPU(struct aa_local_cache, aa_local_buffers); > static void apparmor_cred_free(struct cred *cred) > { > aa_put_label(cred_label(cred)); > set_cred_label(cred, NULL); > } > > -/* > - * allocate the apparmor part of blank credentials > - */ > -static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp) > -{ > - set_cred_label(cred, NULL); > - return 0; > -} > - > /* > * prepare new cred label for modification by prepare_cred block > */ > static int apparmor_cred_prepare(struct cred *new, const struct cred *old, > gfp_t gfp) > { > set_cred_label(new, aa_get_newest_label(cred_label(old))); > return 0; > } > > -/* > - * transfer the apparmor data to a blank set of creds > - */ > -static void apparmor_cred_transfer(struct cred *new, const struct cred *old) > -{ > - set_cred_label(new, aa_get_newest_label(cred_label(old))); > -} > - > static void apparmor_task_free(struct task_struct *task) > { > > aa_free_task_ctx(task_ctx(task)); > } > > @@ -1504,16 +1487,14 @@ static struct security_hook_list apparmor_hooks[] __ro_after_init = { > apparmor_socket_getpeersec_dgram), > LSM_HOOK_INIT(sock_graft, apparmor_sock_graft), > #ifdef CONFIG_NETWORK_SECMARK > LSM_HOOK_INIT(inet_conn_request, apparmor_inet_conn_request), > #endif > > - LSM_HOOK_INIT(cred_alloc_blank, apparmor_cred_alloc_blank), > LSM_HOOK_INIT(cred_free, apparmor_cred_free), > LSM_HOOK_INIT(cred_prepare, apparmor_cred_prepare), > - LSM_HOOK_INIT(cred_transfer, apparmor_cred_transfer), > > LSM_HOOK_INIT(bprm_creds_for_exec, apparmor_bprm_creds_for_exec), > LSM_HOOK_INIT(bprm_committing_creds, apparmor_bprm_committing_creds), > LSM_HOOK_INIT(bprm_committed_creds, apparmor_bprm_committed_creds), > > LSM_HOOK_INIT(task_free, apparmor_task_free), > diff --git a/security/landlock/cred.c b/security/landlock/cred.c > index db9fe7d906ba..786af18c4a1c 100644 > --- a/security/landlock/cred.c > +++ b/security/landlock/cred.c > @@ -11,41 +11,34 @@ > > #include "common.h" > #include "cred.h" > #include "ruleset.h" > #include "setup.h" > > -static void hook_cred_transfer(struct cred *const new, > - const struct cred *const old) > +static int hook_cred_prepare(struct cred *const new, > + const struct cred *const old, const gfp_t gfp) > { > struct landlock_ruleset *const old_dom = landlock_cred(old)->domain; > > if (old_dom) { > landlock_get_ruleset(old_dom); > landlock_cred(new)->domain = old_dom; > } > -} > - > -static int hook_cred_prepare(struct cred *const new, > - const struct cred *const old, const gfp_t gfp) > -{ > - hook_cred_transfer(new, old); > return 0; > } > > static void hook_cred_free(struct cred *const cred) > { > struct landlock_ruleset *const dom = landlock_cred(cred)->domain; > > if (dom) > landlock_put_ruleset_deferred(dom); > } > > static struct security_hook_list landlock_hooks[] __ro_after_init = { > LSM_HOOK_INIT(cred_prepare, hook_cred_prepare), > - LSM_HOOK_INIT(cred_transfer, hook_cred_transfer), > LSM_HOOK_INIT(cred_free, hook_cred_free), > }; > > __init void landlock_add_cred_hooks(void) > { > security_add_hooks(landlock_hooks, ARRAY_SIZE(landlock_hooks), > diff --git a/security/security.c b/security/security.c > index 8cee5b6c6e6d..4fb81de5cf80 100644 > --- a/security/security.c > +++ b/security/security.c > @@ -3057,35 +3057,12 @@ void security_task_free(struct task_struct *task) > call_void_hook(task_free, task); > > kfree(task->security); > task->security = NULL; > } > > -/** > - * security_cred_alloc_blank() - Allocate the min memory to allow cred_transfer > - * @cred: credentials > - * @gfp: gfp flags > - * > - * Only allocate sufficient memory and attach to @cred such that > - * cred_transfer() will not get ENOMEM. > - * > - * Return: Returns 0 on success, negative values on failure. > - */ > -int security_cred_alloc_blank(struct cred *cred, gfp_t gfp) > -{ > - int rc = lsm_cred_alloc(cred, gfp); > - > - if (rc) > - return rc; > - > - rc = call_int_hook(cred_alloc_blank, cred, gfp); > - if (unlikely(rc)) > - security_cred_free(cred); > - return rc; > -} > - > /** > * security_cred_free() - Free the cred's LSM blob and associated resources > * @cred: credentials > * > * Deallocate and clear the cred->security field in a set of credentials. > */ > @@ -3124,24 +3101,12 @@ int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp) > rc = call_int_hook(cred_prepare, new, old, gfp); > if (unlikely(rc)) > security_cred_free(new); > return rc; > } > > -/** > - * security_transfer_creds() - Transfer creds > - * @new: target credentials > - * @old: original credentials > - * > - * Transfer data from original creds to new creds. > - */ > -void security_transfer_creds(struct cred *new, const struct cred *old) > -{ > - call_void_hook(cred_transfer, new, old); > -} > - > /** > * security_cred_getsecid() - Get the secid from a set of credentials > * @c: credentials > * @secid: secid value > * > * Retrieve the security identifier of the cred structure @c. In case of > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c > index 55c78c318ccd..8a659475cc12 100644 > --- a/security/selinux/hooks.c > +++ b/security/selinux/hooks.c > @@ -4007,23 +4007,12 @@ static int selinux_cred_prepare(struct cred *new, const struct cred *old, > struct task_security_struct *tsec = selinux_cred(new); > > *tsec = *old_tsec; > return 0; > } > > -/* > - * transfer the SELinux data to a blank set of creds > - */ > -static void selinux_cred_transfer(struct cred *new, const struct cred *old) > -{ > - const struct task_security_struct *old_tsec = selinux_cred(old); > - struct task_security_struct *tsec = selinux_cred(new); > - > - *tsec = *old_tsec; > -} > - > static void selinux_cred_getsecid(const struct cred *c, u32 *secid) > { > *secid = cred_sid(c); > } > > /* > @@ -7213,13 +7202,12 @@ static struct security_hook_list selinux_hooks[] __ro_after_init = { > LSM_HOOK_INIT(file_receive, selinux_file_receive), > > LSM_HOOK_INIT(file_open, selinux_file_open), > > LSM_HOOK_INIT(task_alloc, selinux_task_alloc), > LSM_HOOK_INIT(cred_prepare, selinux_cred_prepare), > - LSM_HOOK_INIT(cred_transfer, selinux_cred_transfer), > LSM_HOOK_INIT(cred_getsecid, selinux_cred_getsecid), > LSM_HOOK_INIT(kernel_act_as, selinux_kernel_act_as), > LSM_HOOK_INIT(kernel_create_files_as, selinux_kernel_create_files_as), > LSM_HOOK_INIT(kernel_module_request, selinux_kernel_module_request), > LSM_HOOK_INIT(kernel_load_data, selinux_kernel_load_data), > LSM_HOOK_INIT(kernel_read_file, selinux_kernel_read_file), > diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c > index 4164699cd4f6..4cc658deb08b 100644 > --- a/security/smack/smack_lsm.c > +++ b/security/smack/smack_lsm.c > @@ -2050,27 +2050,12 @@ static int smack_file_open(struct file *file) > } > > /* > * Task hooks > */ > > -/** > - * smack_cred_alloc_blank - "allocate" blank task-level security credentials > - * @cred: the new credentials > - * @gfp: the atomicity of any memory allocations > - * > - * Prepare a blank set of credentials for modification. This must allocate all > - * the memory the LSM module might require such that cred_transfer() can > - * complete without error. > - */ > -static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp) > -{ > - init_task_smack(smack_cred(cred), NULL, NULL); > - return 0; > -} > - > > /** > * smack_cred_free - "free" task-level security credentials > * @cred: the credentials in question > * > */ > @@ -2113,27 +2098,12 @@ static int smack_cred_prepare(struct cred *new, const struct cred *old, > > rc = smk_copy_relabel(&new_tsp->smk_relabel, &old_tsp->smk_relabel, > gfp); > return rc; > } > > -/** > - * smack_cred_transfer - Transfer the old credentials to the new credentials > - * @new: the new credentials > - * @old: the original credentials > - * > - * Fill in a set of blank credentials from another set of credentials. > - */ > -static void smack_cred_transfer(struct cred *new, const struct cred *old) > -{ > - struct task_smack *old_tsp = smack_cred(old); > - struct task_smack *new_tsp = smack_cred(new); > - > - init_task_smack(new_tsp, old_tsp->smk_task, old_tsp->smk_task); > -} > - > /** > * smack_cred_getsecid - get the secid corresponding to a creds structure > * @cred: the object creds > * @secid: where to put the result > * > * Sets the secid to contain a u32 version of the smack label. > @@ -5107,16 +5077,14 @@ static struct security_hook_list smack_hooks[] __ro_after_init = { > LSM_HOOK_INIT(file_set_fowner, smack_file_set_fowner), > LSM_HOOK_INIT(file_send_sigiotask, smack_file_send_sigiotask), > LSM_HOOK_INIT(file_receive, smack_file_receive), > > LSM_HOOK_INIT(file_open, smack_file_open), > > - LSM_HOOK_INIT(cred_alloc_blank, smack_cred_alloc_blank), > LSM_HOOK_INIT(cred_free, smack_cred_free), > LSM_HOOK_INIT(cred_prepare, smack_cred_prepare), > - LSM_HOOK_INIT(cred_transfer, smack_cred_transfer), > LSM_HOOK_INIT(cred_getsecid, smack_cred_getsecid), > LSM_HOOK_INIT(kernel_act_as, smack_kernel_act_as), > LSM_HOOK_INIT(kernel_create_files_as, smack_kernel_create_files_as), > LSM_HOOK_INIT(task_setpgid, smack_task_setpgid), > LSM_HOOK_INIT(task_getpgid, smack_task_getpgid), > LSM_HOOK_INIT(task_getsid, smack_task_getsid), I'll give this reviewd-by as soon as getting some feedback David on 1/2. I mean this is dead obvious with a condition. BR, Jarkko
diff --git a/include/linux/cred.h b/include/linux/cred.h index 2976f534a7a3..54b5105d4cd5 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -147,13 +147,12 @@ struct cred { } __randomize_layout; extern void __put_cred(struct cred *); extern void exit_creds(struct task_struct *); extern int copy_creds(struct task_struct *, unsigned long); extern const struct cred *get_task_cred(struct task_struct *); -extern struct cred *cred_alloc_blank(void); extern struct cred *prepare_creds(void); extern struct cred *prepare_exec_creds(void); extern int commit_creds(struct cred *); extern void abort_creds(struct cred *); extern const struct cred *override_creds(const struct cred *); extern void revert_creds(const struct cred *); diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 855db460e08b..1d75075cb607 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -204,18 +204,15 @@ LSM_HOOK(int, 0, file_receive, struct file *file) LSM_HOOK(int, 0, file_open, struct file *file) LSM_HOOK(int, 0, file_post_open, struct file *file, int mask) LSM_HOOK(int, 0, file_truncate, struct file *file) LSM_HOOK(int, 0, task_alloc, struct task_struct *task, unsigned long clone_flags) LSM_HOOK(void, LSM_RET_VOID, task_free, struct task_struct *task) -LSM_HOOK(int, 0, cred_alloc_blank, struct cred *cred, gfp_t gfp) LSM_HOOK(void, LSM_RET_VOID, cred_free, struct cred *cred) LSM_HOOK(int, 0, cred_prepare, struct cred *new, const struct cred *old, gfp_t gfp) -LSM_HOOK(void, LSM_RET_VOID, cred_transfer, struct cred *new, - const struct cred *old) LSM_HOOK(void, LSM_RET_VOID, cred_getsecid, const struct cred *c, u32 *secid) LSM_HOOK(int, 0, kernel_act_as, struct cred *new, u32 secid) LSM_HOOK(int, 0, kernel_create_files_as, struct cred *new, struct inode *inode) LSM_HOOK(int, 0, kernel_module_request, char *kmod_name) LSM_HOOK(int, 0, kernel_load_data, enum kernel_load_data_id id, bool contents) LSM_HOOK(int, 0, kernel_post_load_data, char *buf, loff_t size, diff --git a/include/linux/security.h b/include/linux/security.h index 1390f1efb4f0..a366c2a03f55 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -421,16 +421,14 @@ int security_file_send_sigiotask(struct task_struct *tsk, int security_file_receive(struct file *file); int security_file_open(struct file *file); int security_file_post_open(struct file *file, int mask); int security_file_truncate(struct file *file); int security_task_alloc(struct task_struct *task, unsigned long clone_flags); void security_task_free(struct task_struct *task); -int security_cred_alloc_blank(struct cred *cred, gfp_t gfp); void security_cred_free(struct cred *cred); int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp); -void security_transfer_creds(struct cred *new, const struct cred *old); void security_cred_getsecid(const struct cred *c, u32 *secid); int security_kernel_act_as(struct cred *new, u32 secid); int security_kernel_create_files_as(struct cred *new, struct inode *inode); int security_kernel_module_request(char *kmod_name); int security_kernel_load_data(enum kernel_load_data_id id, bool contents); int security_kernel_post_load_data(char *buf, loff_t size, @@ -1117,32 +1115,22 @@ static inline int security_task_alloc(struct task_struct *task, return 0; } static inline void security_task_free(struct task_struct *task) { } -static inline int security_cred_alloc_blank(struct cred *cred, gfp_t gfp) -{ - return 0; -} - static inline void security_cred_free(struct cred *cred) { } static inline int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp) { return 0; } -static inline void security_transfer_creds(struct cred *new, - const struct cred *old) -{ -} - static inline void security_cred_getsecid(const struct cred *c, u32 *secid) { *secid = 0; } static inline int security_kernel_act_as(struct cred *cred, u32 secid) diff --git a/kernel/cred.c b/kernel/cred.c index 075cfa7c896f..b2f6130cd6b7 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -163,35 +163,12 @@ const struct cred *get_task_cred(struct task_struct *task) rcu_read_unlock(); return cred; } EXPORT_SYMBOL(get_task_cred); -/* - * Allocate blank credentials, such that the credentials can be filled in at a - * later date without risk of ENOMEM. - */ -struct cred *cred_alloc_blank(void) -{ - struct cred *new; - - new = kmem_cache_zalloc(cred_jar, GFP_KERNEL); - if (!new) - return NULL; - - atomic_long_set(&new->usage, 1); - if (security_cred_alloc_blank(new, GFP_KERNEL_ACCOUNT) < 0) - goto error; - - return new; - -error: - abort_creds(new); - return NULL; -} - /** * prepare_creds - Prepare a new set of credentials for modification * * Prepare a new set of task credentials for modification. A task's creds * shouldn't generally be modified directly, therefore this function is used to * prepare a new copy, which the caller then modifies and then commits by diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index 808060f9effb..089d53978d9e 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -74,39 +74,22 @@ static DEFINE_PER_CPU(struct aa_local_cache, aa_local_buffers); static void apparmor_cred_free(struct cred *cred) { aa_put_label(cred_label(cred)); set_cred_label(cred, NULL); } -/* - * allocate the apparmor part of blank credentials - */ -static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp) -{ - set_cred_label(cred, NULL); - return 0; -} - /* * prepare new cred label for modification by prepare_cred block */ static int apparmor_cred_prepare(struct cred *new, const struct cred *old, gfp_t gfp) { set_cred_label(new, aa_get_newest_label(cred_label(old))); return 0; } -/* - * transfer the apparmor data to a blank set of creds - */ -static void apparmor_cred_transfer(struct cred *new, const struct cred *old) -{ - set_cred_label(new, aa_get_newest_label(cred_label(old))); -} - static void apparmor_task_free(struct task_struct *task) { aa_free_task_ctx(task_ctx(task)); } @@ -1504,16 +1487,14 @@ static struct security_hook_list apparmor_hooks[] __ro_after_init = { apparmor_socket_getpeersec_dgram), LSM_HOOK_INIT(sock_graft, apparmor_sock_graft), #ifdef CONFIG_NETWORK_SECMARK LSM_HOOK_INIT(inet_conn_request, apparmor_inet_conn_request), #endif - LSM_HOOK_INIT(cred_alloc_blank, apparmor_cred_alloc_blank), LSM_HOOK_INIT(cred_free, apparmor_cred_free), LSM_HOOK_INIT(cred_prepare, apparmor_cred_prepare), - LSM_HOOK_INIT(cred_transfer, apparmor_cred_transfer), LSM_HOOK_INIT(bprm_creds_for_exec, apparmor_bprm_creds_for_exec), LSM_HOOK_INIT(bprm_committing_creds, apparmor_bprm_committing_creds), LSM_HOOK_INIT(bprm_committed_creds, apparmor_bprm_committed_creds), LSM_HOOK_INIT(task_free, apparmor_task_free), diff --git a/security/landlock/cred.c b/security/landlock/cred.c index db9fe7d906ba..786af18c4a1c 100644 --- a/security/landlock/cred.c +++ b/security/landlock/cred.c @@ -11,41 +11,34 @@ #include "common.h" #include "cred.h" #include "ruleset.h" #include "setup.h" -static void hook_cred_transfer(struct cred *const new, - const struct cred *const old) +static int hook_cred_prepare(struct cred *const new, + const struct cred *const old, const gfp_t gfp) { struct landlock_ruleset *const old_dom = landlock_cred(old)->domain; if (old_dom) { landlock_get_ruleset(old_dom); landlock_cred(new)->domain = old_dom; } -} - -static int hook_cred_prepare(struct cred *const new, - const struct cred *const old, const gfp_t gfp) -{ - hook_cred_transfer(new, old); return 0; } static void hook_cred_free(struct cred *const cred) { struct landlock_ruleset *const dom = landlock_cred(cred)->domain; if (dom) landlock_put_ruleset_deferred(dom); } static struct security_hook_list landlock_hooks[] __ro_after_init = { LSM_HOOK_INIT(cred_prepare, hook_cred_prepare), - LSM_HOOK_INIT(cred_transfer, hook_cred_transfer), LSM_HOOK_INIT(cred_free, hook_cred_free), }; __init void landlock_add_cred_hooks(void) { security_add_hooks(landlock_hooks, ARRAY_SIZE(landlock_hooks), diff --git a/security/security.c b/security/security.c index 8cee5b6c6e6d..4fb81de5cf80 100644 --- a/security/security.c +++ b/security/security.c @@ -3057,35 +3057,12 @@ void security_task_free(struct task_struct *task) call_void_hook(task_free, task); kfree(task->security); task->security = NULL; } -/** - * security_cred_alloc_blank() - Allocate the min memory to allow cred_transfer - * @cred: credentials - * @gfp: gfp flags - * - * Only allocate sufficient memory and attach to @cred such that - * cred_transfer() will not get ENOMEM. - * - * Return: Returns 0 on success, negative values on failure. - */ -int security_cred_alloc_blank(struct cred *cred, gfp_t gfp) -{ - int rc = lsm_cred_alloc(cred, gfp); - - if (rc) - return rc; - - rc = call_int_hook(cred_alloc_blank, cred, gfp); - if (unlikely(rc)) - security_cred_free(cred); - return rc; -} - /** * security_cred_free() - Free the cred's LSM blob and associated resources * @cred: credentials * * Deallocate and clear the cred->security field in a set of credentials. */ @@ -3124,24 +3101,12 @@ int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp) rc = call_int_hook(cred_prepare, new, old, gfp); if (unlikely(rc)) security_cred_free(new); return rc; } -/** - * security_transfer_creds() - Transfer creds - * @new: target credentials - * @old: original credentials - * - * Transfer data from original creds to new creds. - */ -void security_transfer_creds(struct cred *new, const struct cred *old) -{ - call_void_hook(cred_transfer, new, old); -} - /** * security_cred_getsecid() - Get the secid from a set of credentials * @c: credentials * @secid: secid value * * Retrieve the security identifier of the cred structure @c. In case of diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 55c78c318ccd..8a659475cc12 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -4007,23 +4007,12 @@ static int selinux_cred_prepare(struct cred *new, const struct cred *old, struct task_security_struct *tsec = selinux_cred(new); *tsec = *old_tsec; return 0; } -/* - * transfer the SELinux data to a blank set of creds - */ -static void selinux_cred_transfer(struct cred *new, const struct cred *old) -{ - const struct task_security_struct *old_tsec = selinux_cred(old); - struct task_security_struct *tsec = selinux_cred(new); - - *tsec = *old_tsec; -} - static void selinux_cred_getsecid(const struct cred *c, u32 *secid) { *secid = cred_sid(c); } /* @@ -7213,13 +7202,12 @@ static struct security_hook_list selinux_hooks[] __ro_after_init = { LSM_HOOK_INIT(file_receive, selinux_file_receive), LSM_HOOK_INIT(file_open, selinux_file_open), LSM_HOOK_INIT(task_alloc, selinux_task_alloc), LSM_HOOK_INIT(cred_prepare, selinux_cred_prepare), - LSM_HOOK_INIT(cred_transfer, selinux_cred_transfer), LSM_HOOK_INIT(cred_getsecid, selinux_cred_getsecid), LSM_HOOK_INIT(kernel_act_as, selinux_kernel_act_as), LSM_HOOK_INIT(kernel_create_files_as, selinux_kernel_create_files_as), LSM_HOOK_INIT(kernel_module_request, selinux_kernel_module_request), LSM_HOOK_INIT(kernel_load_data, selinux_kernel_load_data), LSM_HOOK_INIT(kernel_read_file, selinux_kernel_read_file), diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 4164699cd4f6..4cc658deb08b 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -2050,27 +2050,12 @@ static int smack_file_open(struct file *file) } /* * Task hooks */ -/** - * smack_cred_alloc_blank - "allocate" blank task-level security credentials - * @cred: the new credentials - * @gfp: the atomicity of any memory allocations - * - * Prepare a blank set of credentials for modification. This must allocate all - * the memory the LSM module might require such that cred_transfer() can - * complete without error. - */ -static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp) -{ - init_task_smack(smack_cred(cred), NULL, NULL); - return 0; -} - /** * smack_cred_free - "free" task-level security credentials * @cred: the credentials in question * */ @@ -2113,27 +2098,12 @@ static int smack_cred_prepare(struct cred *new, const struct cred *old, rc = smk_copy_relabel(&new_tsp->smk_relabel, &old_tsp->smk_relabel, gfp); return rc; } -/** - * smack_cred_transfer - Transfer the old credentials to the new credentials - * @new: the new credentials - * @old: the original credentials - * - * Fill in a set of blank credentials from another set of credentials. - */ -static void smack_cred_transfer(struct cred *new, const struct cred *old) -{ - struct task_smack *old_tsp = smack_cred(old); - struct task_smack *new_tsp = smack_cred(new); - - init_task_smack(new_tsp, old_tsp->smk_task, old_tsp->smk_task); -} - /** * smack_cred_getsecid - get the secid corresponding to a creds structure * @cred: the object creds * @secid: where to put the result * * Sets the secid to contain a u32 version of the smack label. @@ -5107,16 +5077,14 @@ static struct security_hook_list smack_hooks[] __ro_after_init = { LSM_HOOK_INIT(file_set_fowner, smack_file_set_fowner), LSM_HOOK_INIT(file_send_sigiotask, smack_file_send_sigiotask), LSM_HOOK_INIT(file_receive, smack_file_receive), LSM_HOOK_INIT(file_open, smack_file_open), - LSM_HOOK_INIT(cred_alloc_blank, smack_cred_alloc_blank), LSM_HOOK_INIT(cred_free, smack_cred_free), LSM_HOOK_INIT(cred_prepare, smack_cred_prepare), - LSM_HOOK_INIT(cred_transfer, smack_cred_transfer), LSM_HOOK_INIT(cred_getsecid, smack_cred_getsecid), LSM_HOOK_INIT(kernel_act_as, smack_kernel_act_as), LSM_HOOK_INIT(kernel_create_files_as, smack_kernel_create_files_as), LSM_HOOK_INIT(task_setpgid, smack_task_setpgid), LSM_HOOK_INIT(task_getpgid, smack_task_getpgid), LSM_HOOK_INIT(task_getsid, smack_task_getsid),
Now that they're unused thanks to the preceding commit, remove cred_alloc_blank(), security_transfer_creds(), and the corresponding LSM hook implementations. Signed-off-by: Jann Horn <jannh@google.com> --- include/linux/cred.h | 1 - include/linux/lsm_hook_defs.h | 3 --- include/linux/security.h | 12 ------------ kernel/cred.c | 23 ----------------------- security/apparmor/lsm.c | 19 ------------------- security/landlock/cred.c | 11 ++--------- security/security.c | 35 ----------------------------------- security/selinux/hooks.c | 12 ------------ security/smack/smack_lsm.c | 32 -------------------------------- 9 files changed, 2 insertions(+), 146 deletions(-)