5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Bradley Morgan <redacted>
commit 8861f6d5c0678a7c5089c7b272509fc5931b8437 upstream.
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: <redacted>
Reported-by: <redacted>
Link: https://lore.kernel.org/all/6a8f89e5.1d9ded08.62e62.00bf.GAE@google.com/ (local)
Signed-off-by: Bradley Morgan <redacted>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
security/integrity/ima/ima_appraise.c | 2 ++
1 file changed, 2 insertions(+)
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -634,6 +634,8 @@ static int validate_hash_algo(struct den
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);