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-rw-r--r--fs/exec.c31
-rw-r--r--fs/nfsd/auth.c92
-rw-r--r--fs/nfsd/nfs4recover.c68
-rw-r--r--fs/nfsd/nfsfh.c11
-rw-r--r--fs/open.c31
5 files changed, 138 insertions, 95 deletions
diff --git a/fs/exec.c b/fs/exec.c
index a5330e1a2216..9bd3559ddece 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1007,13 +1007,12 @@ int flush_old_exec(struct linux_binprm * bprm)
*/
current->mm->task_size = TASK_SIZE;
- if (bprm->e_uid != current_euid() || bprm->e_gid != current_egid()) {
- suid_keys(current);
+ if (bprm->e_uid != current_euid() ||
+ bprm->e_gid != current_egid()) {
set_dumpable(current->mm, suid_dumpable);
current->pdeath_signal = 0;
} else if (file_permission(bprm->file, MAY_READ) ||
(bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)) {
- suid_keys(current);
set_dumpable(current->mm, suid_dumpable);
}
@@ -1096,10 +1095,8 @@ void compute_creds(struct linux_binprm *bprm)
{
int unsafe;
- if (bprm->e_uid != current_uid()) {
- suid_keys(current);
+ if (bprm->e_uid != current_uid())
current->pdeath_signal = 0;
- }
exec_keys(current);
task_lock(current);
@@ -1709,8 +1706,9 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
struct linux_binfmt * binfmt;
struct inode * inode;
struct file * file;
+ const struct cred *old_cred;
+ struct cred *cred;
int retval = 0;
- int fsuid = current_fsuid();
int flag = 0;
int ispipe = 0;
unsigned long core_limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
@@ -1723,12 +1721,20 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
binfmt = current->binfmt;
if (!binfmt || !binfmt->core_dump)
goto fail;
+
+ cred = prepare_creds();
+ if (!cred) {
+ retval = -ENOMEM;
+ goto fail;
+ }
+
down_write(&mm->mmap_sem);
/*
* If another thread got here first, or we are not dumpable, bail out.
*/
if (mm->core_state || !get_dumpable(mm)) {
up_write(&mm->mmap_sem);
+ put_cred(cred);
goto fail;
}
@@ -1739,12 +1745,16 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
*/
if (get_dumpable(mm) == 2) { /* Setuid core dump mode */
flag = O_EXCL; /* Stop rewrite attacks */
- current->cred->fsuid = 0; /* Dump root private */
+ cred->fsuid = 0; /* Dump root private */
}
retval = coredump_wait(exit_code, &core_state);
- if (retval < 0)
+ if (retval < 0) {
+ put_cred(cred);
goto fail;
+ }
+
+ old_cred = override_creds(cred);
/*
* Clear any false indication of pending signals that might
@@ -1835,7 +1845,8 @@ fail_unlock:
if (helper_argv)
argv_free(helper_argv);
- current->cred->fsuid = fsuid;
+ revert_creds(old_cred);
+ put_cred(cred);
coredump_finish(mm);
fail:
return retval;
diff --git a/fs/nfsd/auth.c b/fs/nfsd/auth.c
index 808fc03a6fbd..836ffa1047d9 100644
--- a/fs/nfsd/auth.c
+++ b/fs/nfsd/auth.c
@@ -27,55 +27,67 @@ int nfsexp_flags(struct svc_rqst *rqstp, struct svc_export *exp)
int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp)
{
- struct cred *act_as = current->cred ;
- struct svc_cred cred = rqstp->rq_cred;
+ struct group_info *rqgi;
+ struct group_info *gi;
+ struct cred *new;
int i;
int flags = nfsexp_flags(rqstp, exp);
int ret;
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
+
+ new->fsuid = rqstp->rq_cred.cr_uid;
+ new->fsgid = rqstp->rq_cred.cr_gid;
+
+ rqgi = rqstp->rq_cred.cr_group_info;
+
if (flags & NFSEXP_ALLSQUASH) {
- cred.cr_uid = exp->ex_anon_uid;
- cred.cr_gid = exp->ex_anon_gid;
- cred.cr_group_info = groups_alloc(0);
+ new->fsuid = exp->ex_anon_uid;
+ new->fsgid = exp->ex_anon_gid;
+ gi = groups_alloc(0);
} else if (flags & NFSEXP_ROOTSQUASH) {
- struct group_info *gi;
- if (!cred.cr_uid)
- cred.cr_uid = exp->ex_anon_uid;
- if (!cred.cr_gid)
- cred.cr_gid = exp->ex_anon_gid;
- gi = groups_alloc(cred.cr_group_info->ngroups);
- if (gi)
- for (i = 0; i < cred.cr_group_info->ngroups; i++) {
- if (!GROUP_AT(cred.cr_group_info, i))
- GROUP_AT(gi, i) = exp->ex_anon_gid;
- else
- GROUP_AT(gi, i) = GROUP_AT(cred.cr_group_info, i);
- }
- cred.cr_group_info = gi;
- } else
- get_group_info(cred.cr_group_info);
-
- if (cred.cr_uid != (uid_t) -1)
- act_as->fsuid = cred.cr_uid;
- else
- act_as->fsuid = exp->ex_anon_uid;
- if (cred.cr_gid != (gid_t) -1)
- act_as->fsgid = cred.cr_gid;
- else
- act_as->fsgid = exp->ex_anon_gid;
+ if (!new->fsuid)
+ new->fsuid = exp->ex_anon_uid;
+ if (!new->fsgid)
+ new->fsgid = exp->ex_anon_gid;
- if (!cred.cr_group_info)
- return -ENOMEM;
- ret = set_groups(act_as, cred.cr_group_info);
- put_group_info(cred.cr_group_info);
- if ((cred.cr_uid)) {
- act_as->cap_effective =
- cap_drop_nfsd_set(act_as->cap_effective);
+ gi = groups_alloc(rqgi->ngroups);
+ if (!gi)
+ goto oom;
+
+ for (i = 0; i < rqgi->ngroups; i++) {
+ if (!GROUP_AT(rqgi, i))
+ GROUP_AT(gi, i) = exp->ex_anon_gid;
+ else
+ GROUP_AT(gi, i) = GROUP_AT(rqgi, i);
+ }
} else {
- act_as->cap_effective =
- cap_raise_nfsd_set(act_as->cap_effective,
- act_as->cap_permitted);
+ gi = get_group_info(rqgi);
}
+
+ if (new->fsuid == (uid_t) -1)
+ new->fsuid = exp->ex_anon_uid;
+ if (new->fsgid == (gid_t) -1)
+ new->fsgid = exp->ex_anon_gid;
+
+ ret = set_groups(new, gi);
+ put_group_info(gi);
+ if (!ret)
+ goto error;
+
+ if (new->uid)
+ new->cap_effective = cap_drop_nfsd_set(new->cap_effective);
+ else
+ new->cap_effective = cap_raise_nfsd_set(new->cap_effective,
+ new->cap_permitted);
+ return commit_creds(new);
+
+oom:
+ ret = -ENOMEM;
+error:
+ abort_creds(new);
return ret;
}
diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index 632a50b4b371..9371ea12d7fa 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -54,20 +54,26 @@
static struct path rec_dir;
static int rec_dir_init = 0;
-static void
-nfs4_save_user(uid_t *saveuid, gid_t *savegid)
+static int
+nfs4_save_creds(const struct cred **original_creds)
{
- *saveuid = current->cred->fsuid;
- *savegid = current->cred->fsgid;
- current->cred->fsuid = 0;
- current->cred->fsgid = 0;
+ struct cred *new;
+
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
+
+ new->fsuid = 0;
+ new->fsgid = 0;
+ *original_creds = override_creds(new);
+ put_cred(new);
+ return 0;
}
static void
-nfs4_reset_user(uid_t saveuid, gid_t savegid)
+nfs4_reset_creds(const struct cred *original)
{
- current->cred->fsuid = saveuid;
- current->cred->fsgid = savegid;
+ revert_creds(original);
}
static void
@@ -129,10 +135,9 @@ nfsd4_sync_rec_dir(void)
int
nfsd4_create_clid_dir(struct nfs4_client *clp)
{
+ const struct cred *original_cred;
char *dname = clp->cl_recdir;
struct dentry *dentry;
- uid_t uid;
- gid_t gid;
int status;
dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname);
@@ -140,7 +145,9 @@ nfsd4_create_clid_dir(struct nfs4_client *clp)
if (!rec_dir_init || clp->cl_firststate)
return 0;
- nfs4_save_user(&uid, &gid);
+ status = nfs4_save_creds(&original_cred);
+ if (status < 0)
+ return status;
/* lock the parent */
mutex_lock(&rec_dir.dentry->d_inode->i_mutex);
@@ -168,7 +175,7 @@ out_unlock:
clp->cl_firststate = 1;
nfsd4_sync_rec_dir();
}
- nfs4_reset_user(uid, gid);
+ nfs4_reset_creds(original_cred);
dprintk("NFSD: nfsd4_create_clid_dir returns %d\n", status);
return status;
}
@@ -211,20 +218,21 @@ nfsd4_build_dentrylist(void *arg, const char *name, int namlen,
static int
nfsd4_list_rec_dir(struct dentry *dir, recdir_func *f)
{
+ const struct cred *original_cred;
struct file *filp;
struct dentry_list_arg dla = {
.parent = dir,
};
struct list_head *dentries = &dla.dentries;
struct dentry_list *child;
- uid_t uid;
- gid_t gid;
int status;
if (!rec_dir_init)
return 0;
- nfs4_save_user(&uid, &gid);
+ status = nfs4_save_creds(&original_cred);
+ if (status < 0)
+ return status;
filp = dentry_open(dget(dir), mntget(rec_dir.mnt), O_RDONLY,
current_cred());
@@ -250,7 +258,7 @@ out:
dput(child->dentry);
kfree(child);
}
- nfs4_reset_user(uid, gid);
+ nfs4_reset_creds(original_cred);
return status;
}
@@ -312,8 +320,7 @@ out:
void
nfsd4_remove_clid_dir(struct nfs4_client *clp)
{
- uid_t uid;
- gid_t gid;
+ const struct cred *original_cred;
int status;
if (!rec_dir_init || !clp->cl_firststate)
@@ -323,9 +330,13 @@ nfsd4_remove_clid_dir(struct nfs4_client *clp)
if (status)
goto out;
clp->cl_firststate = 0;
- nfs4_save_user(&uid, &gid);
+
+ status = nfs4_save_creds(&original_cred);
+ if (status < 0)
+ goto out;
+
status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1);
- nfs4_reset_user(uid, gid);
+ nfs4_reset_creds(original_cred);
if (status == 0)
nfsd4_sync_rec_dir();
mnt_drop_write(rec_dir.mnt);
@@ -402,16 +413,21 @@ nfsd4_recdir_load(void) {
void
nfsd4_init_recdir(char *rec_dirname)
{
- uid_t uid = 0;
- gid_t gid = 0;
- int status;
+ const struct cred *original_cred;
+ int status;
printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
rec_dirname);
BUG_ON(rec_dir_init);
- nfs4_save_user(&uid, &gid);
+ status = nfs4_save_creds(&original_cred);
+ if (status < 0) {
+ printk("NFSD: Unable to change credentials to find recovery"
+ " directory: error %d\n",
+ status);
+ return;
+ }
status = kern_path(rec_dirname, LOOKUP_FOLLOW | LOOKUP_DIRECTORY,
&rec_dir);
@@ -421,7 +437,7 @@ nfsd4_init_recdir(char *rec_dirname)
if (!status)
rec_dir_init = 1;
- nfs4_reset_user(uid, gid);
+ nfs4_reset_creds(original_cred);
}
void
diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
index e67cfaea0865..f0da7d9c3a92 100644
--- a/fs/nfsd/nfsfh.c
+++ b/fs/nfsd/nfsfh.c
@@ -186,9 +186,14 @@ static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp)
* access control settings being in effect, we cannot
* fix that case easily.
*/
- current->cred->cap_effective =
- cap_raise_nfsd_set(current->cred->cap_effective,
- current->cred->cap_permitted);
+ struct cred *new = prepare_creds();
+ if (!new)
+ return nfserrno(-ENOMEM);
+ new->cap_effective =
+ cap_raise_nfsd_set(new->cap_effective,
+ new->cap_permitted);
+ put_cred(override_creds(new));
+ put_cred(new);
} else {
error = nfsd_setuser_and_check_port(rqstp, exp);
if (error)
diff --git a/fs/open.c b/fs/open.c
index f96eaab280a3..c0a426d5766c 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -425,30 +425,33 @@ out:
*/
asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode)
{
- struct cred *cred = current->cred;
+ const struct cred *old_cred;
+ struct cred *override_cred;
struct path path;
struct inode *inode;
- int old_fsuid, old_fsgid;
- kernel_cap_t uninitialized_var(old_cap); /* !SECURE_NO_SETUID_FIXUP */
int res;
if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */
return -EINVAL;
- old_fsuid = cred->fsuid;
- old_fsgid = cred->fsgid;
+ override_cred = prepare_creds();
+ if (!override_cred)
+ return -ENOMEM;
- cred->fsuid = cred->uid;
- cred->fsgid = cred->gid;
+ override_cred->fsuid = override_cred->uid;
+ override_cred->fsgid = override_cred->gid;
if (!issecure(SECURE_NO_SETUID_FIXUP)) {
/* Clear the capabilities if we switch to a non-root user */
- if (current->cred->uid)
- old_cap = cap_set_effective(__cap_empty_set);
+ if (override_cred->uid)
+ cap_clear(override_cred->cap_effective);
else
- old_cap = cap_set_effective(cred->cap_permitted);
+ override_cred->cap_effective =
+ override_cred->cap_permitted;
}
+ old_cred = override_creds(override_cred);
+
res = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path);
if (res)
goto out;
@@ -485,12 +488,8 @@ asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode)
out_path_release:
path_put(&path);
out:
- cred->fsuid = old_fsuid;
- cred->fsgid = old_fsgid;
-
- if (!issecure(SECURE_NO_SETUID_FIXUP))
- cap_set_effective(old_cap);
-
+ revert_creds(old_cred);
+ put_cred(override_cred);
return res;
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-05 15:38:28 +0000