[PATCH 5.15 256/935] ima: Check for ERR_PTR from dentry_path() in validate_hash_algo()

From
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date
2026-09-12 18:23:54
Also in
linux-patches
Reply to
Greg Kroah-Hartman, 2026-09-12
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);

Thread (970 messages) 970 messages, 11 authors, last reply 2026-09-20
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