Merge: CVE-2025-21964: cifs: Fix integer overflow while processing acregmax mount option

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/6804

JIRA: https://issues.redhat.com/browse/RHEL-87920
CVE: CVE-2025-21964

```
commit 7489161
Author: Murad Masimov <m.masimov@mt-integration.ru>
Date:   Tue Mar 11 17:22:03 2025 +0300

    cifs: Fix integer overflow while processing acregmax mount option

    User-provided mount parameter acregmax of type u32 is intended to have
    an upper limit, but before it is validated, the value is converted from
    seconds to jiffies which can lead to an integer overflow.

    Found by Linux Verification Center (linuxtesting.org) with SVACE.

    Fixes: 5780464 ("cifs: Add new parameter "acregmax" for distinct file and directory metadata timeout")
    Signed-off-by: Murad Masimov <m.masimov@mt-integration.ru>
    Signed-off-by: Steve French <stfrench@microsoft.com>```

Signed-off-by: CKI Backport Bot <cki-ci-bot+cki-gitlab-backport-bot@redhat.com>

---

<small>Created 2025-04-29 14:37 UTC by backporter - [KWF FAQ](https://red.ht/kernel_workflow_doc) - [Slack #team-kernel-workflow](https://redhat-internal.slack.com/archives/C04LRUPMJQ5) - [Source](https://gitlab.com/cki-project/kernel-workflow/-/blob/main/webhook/utils/backporter.py) - [Documentation](https://gitlab.com/cki-project/kernel-workflow/-/blob/main/docs/README.backporter.md) - [Report an issue](https://issues.redhat.com/secure/CreateIssueDetails!init.jspa?pid=12334433&issuetype=1&priority=4&summary=backporter+webhook+issue&components=kernel-workflow+/+backporter)</small>

Approved-by: Paulo Alcantara <paalcant@redhat.com>
Approved-by: Jay Shin <jaeshin@redhat.com>
Approved-by: Benjamin Coddington <bcodding@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: Augusto Caringi <acaringi@redhat.com>

Author: caringi

fs/smb/client/fs_context.c

@@ -1359,11 +1359,11 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,
 		}
 		break;
 	case Opt_acregmax:
-		ctx->acregmax = HZ * result.uint_32;
-		if (ctx->acregmax > CIFS_MAX_ACTIMEO) {
+		if (result.uint_32 > CIFS_MAX_ACTIMEO / HZ) {
 			cifs_errorf(fc, "acregmax too large\n");
 			goto cifs_parse_mount_err;
 		}
+		ctx->acregmax = HZ * result.uint_32;
 		break;
 	case Opt_acdirmax:
 		ctx->acdirmax = HZ * result.uint_32;