From: Darrick J. Wong <djwong@kernel.org>
Date: Fri, 21 Mar 2025 16:31:46 +0000 (-0700)
Subject: xfs_repair: fix crash in reset_rt_metadir_inodes
X-Git-Tag: v6.14.0~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b26d16875213a6a25cc9194d45e4547a42ded5e1;p=thirdparty%2Fxfsprogs-dev.git

xfs_repair: fix crash in reset_rt_metadir_inodes

I observed that xfs_repair -n segfaults during xfs/812 after corrupting
the /rtgroups metadir inode because mp->m_rtdirip isn't loaded.  Fix the
crash and print a warning about the missing inode.

Cc: linux-xfs@vger.kernel.org # v6.13.0
Fixes: 7c541c90fd77a2 ("xfs_repair: support realtime groups")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---

diff --git a/repair/phase6.c b/repair/phase6.c
index 2d526dda..c16164c1 100644
--- a/repair/phase6.c
+++ b/repair/phase6.c
@@ -3397,15 +3397,21 @@ reset_rt_metadir_inodes(
 		unload_rtgroup_inodes(mp);
 
 	if (mp->m_sb.sb_rgcount > 0) {
-		if (!no_modify) {
+		if (no_modify) {
+			if (!mp->m_rtdirip)
+				do_warn(_("would recreate realtime metadir\n"));
+		} else {
 			error = -libxfs_rtginode_mkdir_parent(mp);
 			if (error)
 				do_error(_("failed to create realtime metadir (%d)\n"),
 					error);
 		}
-		mark_ino_inuse(mp, mp->m_rtdirip->i_ino, S_IFDIR,
-				mp->m_metadirip->i_ino);
-		mark_ino_metadata(mp, mp->m_rtdirip->i_ino);
+
+		if (mp->m_rtdirip) {
+			mark_ino_inuse(mp, mp->m_rtdirip->i_ino, S_IFDIR,
+					mp->m_metadirip->i_ino);
+			mark_ino_metadata(mp, mp->m_rtdirip->i_ino);
+		}
 	}
 
 	/*