From 195da3ff244deff119c3f5244b464b2236ea1725 Mon Sep 17 00:00:00 2001 From: Konstantin Andreev Date: Mon, 16 Jun 2025 04:07:29 +0300 Subject: [PATCH] smack: fix bug: SMACK64TRANSMUTE set on non-directory When a new file system object is created and the conditions for label transmutation are met, the SMACK64TRANSMUTE extended attribute is set on the object regardless of its type: file, pipe, socket, symlink, or directory. However, SMACK64TRANSMUTE may only be set on directories. This bug is a combined effect of the commits [1] and [2] which both transfer functionality from smack_d_instantiate() to smack_inode_init_security(), but only in part. Commit [1] set blank SMACK64TRANSMUTE on improper object types. Commit [2] set "TRUE" SMACK64TRANSMUTE on improper object types. [1] 2023-06-10, Fixes: baed456a6a2f ("smack: Set the SMACK64TRANSMUTE xattr in smack_inode_init_security()") Link: https://lore.kernel.org/linux-security-module/20230610075738.3273764-3-roberto.sassu@huaweicloud.com/ [2] 2023-11-16, Fixes: e63d86b8b764 ("smack: Initialize the in-memory inode in smack_inode_init_security()") Link: https://lore.kernel.org/linux-security-module/20231116090125.187209-5-roberto.sassu@huaweicloud.com/ Signed-off-by: Konstantin Andreev Signed-off-by: Casey Schaufler --- security/smack/smack_lsm.c | 26 ++++++++++++++------------ 1 file changed, 14 insertions(+), 12 deletions(-) diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 8629e58ea4fa1..d6f814aa15bae 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -1027,18 +1027,20 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir, if (!trans_cred) issp->smk_inode = dsp; - issp->smk_flags |= SMK_INODE_TRANSMUTE; - xattr_transmute = lsm_get_xattr_slot(xattrs, - xattr_count); - if (xattr_transmute) { - xattr_transmute->value = kmemdup(TRANS_TRUE, - TRANS_TRUE_SIZE, - GFP_NOFS); - if (!xattr_transmute->value) - return -ENOMEM; - - xattr_transmute->value_len = TRANS_TRUE_SIZE; - xattr_transmute->name = XATTR_SMACK_TRANSMUTE; + if (S_ISDIR(inode->i_mode)) { + issp->smk_flags |= SMK_INODE_TRANSMUTE; + xattr_transmute = lsm_get_xattr_slot(xattrs, + xattr_count); + if (xattr_transmute) { + xattr_transmute->value = kmemdup(TRANS_TRUE, + TRANS_TRUE_SIZE, + GFP_NOFS); + if (!xattr_transmute->value) + return -ENOMEM; + + xattr_transmute->value_len = TRANS_TRUE_SIZE; + xattr_transmute->name = XATTR_SMACK_TRANSMUTE; + } } } -- 2.47.3