From: Breno Leitao Date: Thu, 21 Nov 2024 09:57:12 +0000 (-0800) Subject: ima: kexec: silence RCU list traversal warning X-Git-Tag: v6.14-rc1~168^2~2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=68af44a71975688b881ea524e2526bb7c7ad0e9a;p=thirdparty%2Fkernel%2Flinux.git ima: kexec: silence RCU list traversal warning The ima_measurements list is append-only and doesn't require rcu_read_lock() protection. However, lockdep issues a warning when traversing RCU lists without the read lock: security/integrity/ima/ima_kexec.c:40 RCU-list traversed in non-reader section!! Fix this by using the variant of list_for_each_entry_rcu() with the last argument set to true. This tells the RCU subsystem that traversing this append-only list without the read lock is intentional and safe. This change silences the lockdep warning while maintaining the correct semantics for the append-only list traversal. Signed-off-by: Breno Leitao Signed-off-by: Mimi Zohar --- diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c index 52e00332defed..9d45f4d26f731 100644 --- a/security/integrity/ima/ima_kexec.c +++ b/security/integrity/ima/ima_kexec.c @@ -37,7 +37,8 @@ static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer, memset(&khdr, 0, sizeof(khdr)); khdr.version = 1; - list_for_each_entry_rcu(qe, &ima_measurements, later) { + /* This is an append-only list, no need to hold the RCU read lock */ + list_for_each_entry_rcu(qe, &ima_measurements, later, true) { if (file.count < file.size) { khdr.count++; ima_measurements_show(&file, qe);