diff options
author | David S. Miller <davem@davemloft.net> | 2012-11-11 00:32:51 +0100 |
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committer | David S. Miller <davem@davemloft.net> | 2012-11-11 00:32:51 +0100 |
commit | d4185bbf62a5d8d777ee445db1581beb17882a07 (patch) | |
tree | 024b0badbd7c970b1983be6d8c345cc4a290cb31 /security/device_cgroup.c | |
parent | ip6tnl: advertise tunnel param via rtnl (diff) | |
parent | gre6: fix rtnl dump messages (diff) | |
download | linux-d4185bbf62a5d8d777ee445db1581beb17882a07.tar.xz linux-d4185bbf62a5d8d777ee445db1581beb17882a07.zip |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
Minor conflict between the BCM_CNIC define removal in net-next
and a bug fix added to net. Based upon a conflict resolution
patch posted by Stephen Rothwell.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'security/device_cgroup.c')
-rw-r--r-- | security/device_cgroup.c | 87 |
1 files changed, 61 insertions, 26 deletions
diff --git a/security/device_cgroup.c b/security/device_cgroup.c index 44dfc415a379..842c254396db 100644 --- a/security/device_cgroup.c +++ b/security/device_cgroup.c @@ -42,7 +42,10 @@ struct dev_exception_item { struct dev_cgroup { struct cgroup_subsys_state css; struct list_head exceptions; - bool deny_all; + enum { + DEVCG_DEFAULT_ALLOW, + DEVCG_DEFAULT_DENY, + } behavior; }; static inline struct dev_cgroup *css_to_devcgroup(struct cgroup_subsys_state *s) @@ -182,13 +185,13 @@ static struct cgroup_subsys_state *devcgroup_create(struct cgroup *cgroup) parent_cgroup = cgroup->parent; if (parent_cgroup == NULL) - dev_cgroup->deny_all = false; + dev_cgroup->behavior = DEVCG_DEFAULT_ALLOW; else { parent_dev_cgroup = cgroup_to_devcgroup(parent_cgroup); mutex_lock(&devcgroup_mutex); ret = dev_exceptions_copy(&dev_cgroup->exceptions, &parent_dev_cgroup->exceptions); - dev_cgroup->deny_all = parent_dev_cgroup->deny_all; + dev_cgroup->behavior = parent_dev_cgroup->behavior; mutex_unlock(&devcgroup_mutex); if (ret) { kfree(dev_cgroup); @@ -260,7 +263,7 @@ static int devcgroup_seq_read(struct cgroup *cgroup, struct cftype *cft, * - List the exceptions in case the default policy is to deny * This way, the file remains as a "whitelist of devices" */ - if (devcgroup->deny_all == false) { + if (devcgroup->behavior == DEVCG_DEFAULT_ALLOW) { set_access(acc, ACC_MASK); set_majmin(maj, ~0); set_majmin(min, ~0); @@ -314,12 +317,12 @@ static int may_access(struct dev_cgroup *dev_cgroup, * In two cases we'll consider this new exception valid: * - the dev cgroup has its default policy to allow + exception list: * the new exception should *not* match any of the exceptions - * (!deny_all, !match) + * (behavior == DEVCG_DEFAULT_ALLOW, !match) * - the dev cgroup has its default policy to deny + exception list: * the new exception *should* match the exceptions - * (deny_all, match) + * (behavior == DEVCG_DEFAULT_DENY, match) */ - if (dev_cgroup->deny_all == match) + if ((dev_cgroup->behavior == DEVCG_DEFAULT_DENY) == match) return 1; return 0; } @@ -341,6 +344,17 @@ static int parent_has_perm(struct dev_cgroup *childcg, return may_access(parent, ex); } +/** + * may_allow_all - checks if it's possible to change the behavior to + * allow based on parent's rules. + * @parent: device cgroup's parent + * returns: != 0 in case it's allowed, 0 otherwise + */ +static inline int may_allow_all(struct dev_cgroup *parent) +{ + return parent->behavior == DEVCG_DEFAULT_ALLOW; +} + /* * Modify the exception list using allow/deny rules. * CAP_SYS_ADMIN is needed for this. It's at least separate from CAP_MKNOD @@ -358,9 +372,11 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup, int filetype, const char *buffer) { const char *b; - char *endp; - int count; + char temp[12]; /* 11 + 1 characters needed for a u32 */ + int count, rc; struct dev_exception_item ex; + struct cgroup *p = devcgroup->css.cgroup; + struct dev_cgroup *parent = cgroup_to_devcgroup(p->parent); if (!capable(CAP_SYS_ADMIN)) return -EPERM; @@ -372,14 +388,18 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup, case 'a': switch (filetype) { case DEVCG_ALLOW: - if (!parent_has_perm(devcgroup, &ex)) + if (!may_allow_all(parent)) return -EPERM; dev_exception_clean(devcgroup); - devcgroup->deny_all = false; + rc = dev_exceptions_copy(&devcgroup->exceptions, + &parent->exceptions); + if (rc) + return rc; + devcgroup->behavior = DEVCG_DEFAULT_ALLOW; break; case DEVCG_DENY: dev_exception_clean(devcgroup); - devcgroup->deny_all = true; + devcgroup->behavior = DEVCG_DEFAULT_DENY; break; default: return -EINVAL; @@ -402,8 +422,16 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup, ex.major = ~0; b++; } else if (isdigit(*b)) { - ex.major = simple_strtoul(b, &endp, 10); - b = endp; + memset(temp, 0, sizeof(temp)); + for (count = 0; count < sizeof(temp) - 1; count++) { + temp[count] = *b; + b++; + if (!isdigit(*b)) + break; + } + rc = kstrtou32(temp, 10, &ex.major); + if (rc) + return -EINVAL; } else { return -EINVAL; } @@ -416,8 +444,16 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup, ex.minor = ~0; b++; } else if (isdigit(*b)) { - ex.minor = simple_strtoul(b, &endp, 10); - b = endp; + memset(temp, 0, sizeof(temp)); + for (count = 0; count < sizeof(temp) - 1; count++) { + temp[count] = *b; + b++; + if (!isdigit(*b)) + break; + } + rc = kstrtou32(temp, 10, &ex.minor); + if (rc) + return -EINVAL; } else { return -EINVAL; } @@ -452,7 +488,7 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup, * an matching exception instead. And be silent about it: we * don't want to break compatibility */ - if (devcgroup->deny_all == false) { + if (devcgroup->behavior == DEVCG_DEFAULT_ALLOW) { dev_exception_rm(devcgroup, &ex); return 0; } @@ -463,7 +499,7 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup, * an matching exception instead. And be silent about it: we * don't want to break compatibility */ - if (devcgroup->deny_all == true) { + if (devcgroup->behavior == DEVCG_DEFAULT_DENY) { dev_exception_rm(devcgroup, &ex); return 0; } @@ -533,10 +569,10 @@ struct cgroup_subsys devices_subsys = { * * returns 0 on success, -EPERM case the operation is not permitted */ -static int __devcgroup_check_permission(struct dev_cgroup *dev_cgroup, - short type, u32 major, u32 minor, +static int __devcgroup_check_permission(short type, u32 major, u32 minor, short access) { + struct dev_cgroup *dev_cgroup; struct dev_exception_item ex; int rc; @@ -547,6 +583,7 @@ static int __devcgroup_check_permission(struct dev_cgroup *dev_cgroup, ex.access = access; rcu_read_lock(); + dev_cgroup = task_devcgroup(current); rc = may_access(dev_cgroup, &ex); rcu_read_unlock(); @@ -558,7 +595,6 @@ static int __devcgroup_check_permission(struct dev_cgroup *dev_cgroup, int __devcgroup_inode_permission(struct inode *inode, int mask) { - struct dev_cgroup *dev_cgroup = task_devcgroup(current); short type, access = 0; if (S_ISBLK(inode->i_mode)) @@ -570,13 +606,12 @@ int __devcgroup_inode_permission(struct inode *inode, int mask) if (mask & MAY_READ) access |= ACC_READ; - return __devcgroup_check_permission(dev_cgroup, type, imajor(inode), - iminor(inode), access); + return __devcgroup_check_permission(type, imajor(inode), iminor(inode), + access); } int devcgroup_inode_mknod(int mode, dev_t dev) { - struct dev_cgroup *dev_cgroup = task_devcgroup(current); short type; if (!S_ISBLK(mode) && !S_ISCHR(mode)) @@ -587,7 +622,7 @@ int devcgroup_inode_mknod(int mode, dev_t dev) else type = DEV_CHAR; - return __devcgroup_check_permission(dev_cgroup, type, MAJOR(dev), - MINOR(dev), ACC_MKNOD); + return __devcgroup_check_permission(type, MAJOR(dev), MINOR(dev), + ACC_MKNOD); } |