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authorStephen Smalley <sds@tycho.nsa.gov>2017-05-12 12:41:24 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-04-13 19:50:10 +0200
commit60c26da547da81cfe9ea1e7d65d514cc89deb82e (patch)
tree767ed0713b05f75b7eda2caefccba357e2fee972 /security
parent4f58c2e97cf347121220f9c0a12eb910196e50eb (diff)
selinux: do not check open permission on sockets
[ Upstream commit ccb544781d34afdb73a9a73ae53035d824d193bf ] open permission is currently only defined for files in the kernel (COMMON_FILE_PERMS rather than COMMON_FILE_SOCK_PERMS). Construction of an artificial test case that tries to open a socket via /proc/pid/fd will generate a recvfrom avc denial because recvfrom and open happen to map to the same permission bit in socket vs file classes. open of a socket via /proc/pid/fd is not supported by the kernel regardless and will ultimately return ENXIO. But we hit the permission check first and can thus produce these odd/misleading denials. Omit the open check when operating on a socket. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'security')
-rw-r--r--security/selinux/hooks.c10
1 files changed, 7 insertions, 3 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 4f690ab0feed..99212ff6a568 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1942,8 +1942,9 @@ static inline u32 file_to_av(struct file *file)
static inline u32 open_file_to_av(struct file *file)
{
u32 av = file_to_av(file);
+ struct inode *inode = file_inode(file);
- if (selinux_policycap_openperm)
+ if (selinux_policycap_openperm && inode->i_sb->s_magic != SOCKFS_MAGIC)
av |= FILE__OPEN;
return av;
@@ -2912,6 +2913,7 @@ static int selinux_inode_permission(struct inode *inode, int mask)
static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
{
const struct cred *cred = current_cred();
+ struct inode *inode = d_backing_inode(dentry);
unsigned int ia_valid = iattr->ia_valid;
__u32 av = FILE__WRITE;
@@ -2927,8 +2929,10 @@ static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
return dentry_has_perm(cred, dentry, FILE__SETATTR);
- if (selinux_policycap_openperm && (ia_valid & ATTR_SIZE)
- && !(ia_valid & ATTR_FILE))
+ if (selinux_policycap_openperm &&
+ inode->i_sb->s_magic != SOCKFS_MAGIC &&
+ (ia_valid & ATTR_SIZE) &&
+ !(ia_valid & ATTR_FILE))
av |= FILE__OPEN;
return dentry_has_perm(cred, dentry, av);