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| author | David Howells <dhowells@redhat.com> | 2019-05-22 14:06:51 +0100 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2019-05-22 14:06:51 +0100 |
| commit | 2e21865faf4fd7ca99eb2ace072c6d618059e342 (patch) | |
| tree | cb05e816e95bc4785b7c601b2f33d3ad6396e1fc | |
| parent | a188339ca5a396acc588e5851ed7e19f66b0ebd9 (diff) | |
| download | linux-2e21865faf4fd7ca99eb2ace072c6d618059e342.tar.bz2 | |
keys: sparse: Fix key_fs[ug]id_changed()
Sparse warnings are incurred by key_fs[ug]id_changed() due to unprotected
accesses of tsk->cred, which is marked __rcu.
Fix this by passing the new cred struct to these functions from
commit_creds() rather than the task pointer.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
| -rw-r--r-- | include/linux/key.h | 8 | ||||
| -rw-r--r-- | kernel/cred.c | 4 | ||||
| -rw-r--r-- | security/keys/process_keys.c | 22 |
3 files changed, 16 insertions, 18 deletions
diff --git a/include/linux/key.h b/include/linux/key.h index 7099985e35a9..1f09aad1c98c 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -402,8 +402,8 @@ extern struct ctl_table key_sysctls[]; * the userspace interface */ extern int install_thread_keyring_to_cred(struct cred *cred); -extern void key_fsuid_changed(struct task_struct *tsk); -extern void key_fsgid_changed(struct task_struct *tsk); +extern void key_fsuid_changed(struct cred *new_cred); +extern void key_fsgid_changed(struct cred *new_cred); extern void key_init(void); #else /* CONFIG_KEYS */ @@ -418,8 +418,8 @@ extern void key_init(void); #define make_key_ref(k, p) NULL #define key_ref_to_ptr(k) NULL #define is_key_possessed(k) 0 -#define key_fsuid_changed(t) do { } while(0) -#define key_fsgid_changed(t) do { } while(0) +#define key_fsuid_changed(c) do { } while(0) +#define key_fsgid_changed(c) do { } while(0) #define key_init() do { } while(0) #endif /* CONFIG_KEYS */ diff --git a/kernel/cred.c b/kernel/cred.c index 45d77284aed0..3bd40de9e192 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -455,9 +455,9 @@ int commit_creds(struct cred *new) /* alter the thread keyring */ if (!uid_eq(new->fsuid, old->fsuid)) - key_fsuid_changed(task); + key_fsuid_changed(new); if (!gid_eq(new->fsgid, old->fsgid)) - key_fsgid_changed(task); + key_fsgid_changed(new); /* do it * RLIMIT_NPROC limits on user->processes have already been checked diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index f05f7125a7d5..ba5d3172cafe 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -293,28 +293,26 @@ static int install_session_keyring(struct key *keyring) /* * Handle the fsuid changing. */ -void key_fsuid_changed(struct task_struct *tsk) +void key_fsuid_changed(struct cred *new_cred) { /* update the ownership of the thread keyring */ - BUG_ON(!tsk->cred); - if (tsk->cred->thread_keyring) { - down_write(&tsk->cred->thread_keyring->sem); - tsk->cred->thread_keyring->uid = tsk->cred->fsuid; - up_write(&tsk->cred->thread_keyring->sem); + if (new_cred->thread_keyring) { + down_write(&new_cred->thread_keyring->sem); + new_cred->thread_keyring->uid = new_cred->fsuid; + up_write(&new_cred->thread_keyring->sem); } } /* * Handle the fsgid changing. */ -void key_fsgid_changed(struct task_struct *tsk) +void key_fsgid_changed(struct cred *new_cred) { /* update the ownership of the thread keyring */ - BUG_ON(!tsk->cred); - if (tsk->cred->thread_keyring) { - down_write(&tsk->cred->thread_keyring->sem); - tsk->cred->thread_keyring->gid = tsk->cred->fsgid; - up_write(&tsk->cred->thread_keyring->sem); + if (new_cred->thread_keyring) { + down_write(&new_cred->thread_keyring->sem); + new_cred->thread_keyring->gid = new_cred->fsgid; + up_write(&new_cred->thread_keyring->sem); } } |