git: bfc8e3308bee - main - ext2fs: Fix the size of struct ufid and add a static assert

From: Rick Macklem <rmacklem_at_FreeBSD.org>
Date: Fri, 06 Dec 2024 02:06:06 UTC
The branch main has been updated by rmacklem:

URL: https://cgit.FreeBSD.org/src/commit/?id=bfc8e3308bee23d0f7836d57f32ed8d47da02627

commit bfc8e3308bee23d0f7836d57f32ed8d47da02627
Author:     Rick Macklem <rmacklem@FreeBSD.org>
AuthorDate: 2024-12-06 02:05:06 +0000
Commit:     Rick Macklem <rmacklem@FreeBSD.org>
CommitDate: 2024-12-06 02:05:06 +0000

    ext2fs: Fix the size of struct ufid and add a static assert
    
    File system specific *fid structures are copied into the generic
    struct fid defined in sys/mount.h.
    As such, they cannot be larger than struct fid.
    
    This patch packed the structure and checks via a __Static_assert().
    
    Reviewed by:    markj
    MFC after:      2 weeks
---
 sys/fs/ext2fs/ext2_vnops.c | 2 ++
 sys/fs/ext2fs/inode.h      | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/sys/fs/ext2fs/ext2_vnops.c b/sys/fs/ext2fs/ext2_vnops.c
index dfbb11f75421..064c10bd18b2 100644
--- a/sys/fs/ext2fs/ext2_vnops.c
+++ b/sys/fs/ext2fs/ext2_vnops.c
@@ -1889,6 +1889,8 @@ ext2_vptofh(struct vop_vptofh_args *ap)
 {
 	struct inode *ip;
 	struct ufid *ufhp;
+	_Static_assert(sizeof(struct ufid) <= sizeof(struct fid),
+	    "struct ufid cannot be larger than struct fid");
 
 	ip = VTOI(ap->a_vp);
 	ufhp = (struct ufid *)ap->a_fhp;
diff --git a/sys/fs/ext2fs/inode.h b/sys/fs/ext2fs/inode.h
index 9ee1b5672da6..63102deb10b0 100644
--- a/sys/fs/ext2fs/inode.h
+++ b/sys/fs/ext2fs/inode.h
@@ -191,7 +191,7 @@ struct ufid {
 	uint16_t ufid_pad;		/* Force 32-bit alignment. */
 	ino_t	ufid_ino;		/* File number (ino). */
 	uint32_t ufid_gen;		/* Generation number. */
-};
+} __packed;
 #endif	/* _KERNEL */
 
 #endif	/* !_FS_EXT2FS_INODE_H_ */