Re: [RFC][PATCH 1/2] smack: Retrieve transmuting information in smack_inode_getsecurity()
From: Casey Schaufler <casey@schaufler-ca.com>
Date: 2023-05-08 17:24:56
Also in:
linux-unionfs, lkml
On 5/8/2023 10:02 AM, Roberto Sassu wrote:
From: Roberto Sassu <roberto.sassu@huawei.com> Enhance smack_inode_getsecurity() to retrieve the value for SMACK64TRANSMUTE from the inode security blob, similarly to SMACK64. This helps to display accurate values in the situation where the security labels come from mount options and not from xattrs.
I will kick the tires on these patches. They look good at first glance.
quoted hunk ↗ jump to hunk
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> --- security/smack/smack_lsm.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-)diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 7a3e9ab137d..c7e37ed2799 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c@@ -1463,10 +1463,19 @@ static int smack_inode_getsecurity(struct mnt_idmap *idmap, struct super_block *sbp; struct inode *ip = inode; struct smack_known *isp; + struct inode_smack *ispp; + size_t label_len; + char *label = NULL; - if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) + if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { isp = smk_of_inode(inode); - else { + } else if (strcmp(name, XATTR_SMACK_TRANSMUTE) == 0) { + ispp = smack_inode(inode); + if (ispp->smk_flags & SMK_INODE_TRANSMUTE) + label = TRANS_TRUE; + else + label = ""; + } else { /* * The rest of the Smack xattrs are only on sockets. */@@ -1488,13 +1497,18 @@ static int smack_inode_getsecurity(struct mnt_idmap *idmap, return -EOPNOTSUPP; } + if (!label) + label = isp->smk_known; + + label_len = strlen(label); + if (alloc) { - *buffer = kstrdup(isp->smk_known, GFP_KERNEL); + *buffer = kstrdup(label, GFP_KERNEL); if (*buffer == NULL) return -ENOMEM; } - return strlen(isp->smk_known); + return label_len; }