dentry_path() returns ERR_PTR(-ENAMETOOLONG) when the path exceeds the
buffer. validate_hash_algo() passes the result straight to
integrity_audit_msg() without checking. ERR_PTR is not NULL, so
integrity_audit_message() sees a valid pointer and calls strlen() on
it, which faults:
BUG: unable to handle page fault for address: ffffffffffffffdc
RIP: 0010:strlen+0x30/0xa0
Call Trace:
audit_log_untrustedstring+0x19/0x30
integrity_audit_message+0x366/0x4f0
ima_inode_setxattr+0x512/0x5f0
Check for IS_ERR() and use NULL instead, which makes the audit message
skip the name= field instead of crashing.
Fixes: 4f2946aa0c45 ("IMA: introduce a new policy option func=SETXATTR_CHECK")
Cc: [email protected]
Reported-by: [email protected]
Link: https://lore.kernel.org/all/[email protected]/
Signed-off-by: Bradley Morgan <[email protected]>
---
security/integrity/ima/ima_appraise.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/security/integrity/ima/ima_appraise.c
b/security/integrity/ima/ima_appraise.c
index ced2e131b061..b280488e15fc 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -748,6 +748,8 @@ static int validate_hash_algo(struct dentry *dentry,
return -EACCES;
path = dentry_path(dentry, pathbuf, PATH_MAX);
+ if (IS_ERR(path))
+ path = NULL;
integrity_audit_msg(AUDIT_INTEGRITY_DATA, d_inode(dentry), path,
"set_data", errmsg, -EACCES, 0);
--
2.47.3
