[Cluster-devel] [PATCH AUTOSEL 4.9 02/12] gfs2: Free rd_bits later in gfs2_clear_rgrpd to fix use-after-free

[Cluster-devel] [PATCH AUTOSEL 4.9 02/12] gfs2: Free rd_bits later in gfs2_clear_rgrpd to fix use-after-free

[Sasha Levin]

From: Bob Peterson <rpeterso@redhat.com>

[ Upstream commit d0f17d3883f1e3f085d38572c2ea8edbd5150172 ]

Function gfs2_clear_rgrpd calls kfree(rgd->rd_bits) before calling
return_all_reservations, but return_all_reservations still dereferences
rgd->rd_bits in __rs_deltree.  Fix that by moving the call to kfree below the
call to return_all_reservations.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/gfs2/rgrp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 0a80f66365492..0958f76ada6a3 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -730,9 +730,9 @@ void gfs2_clear_rgrpd(struct gfs2_sbd *sdp)
 		}
 
 		gfs2_free_clones(rgd);
+		return_all_reservations(rgd);
 		kfree(rgd->rd_bits);
 		rgd->rd_bits = NULL;
-		return_all_reservations(rgd);
 		kmem_cache_free(gfs2_rgrpd_cachep, rgd);
 	}
 }
-- 
2.27.0

[Cluster-devel] [PATCH AUTOSEL 4.9 03/12] gfs2: check for live vs. read-only file system in gfs2_fitrim

[Sasha Levin]

From: Bob Peterson <rpeterso@redhat.com>

[ Upstream commit c5c68724696e7d2f8db58a5fce3673208d35c485 ]

Before this patch, gfs2_fitrim was not properly checking for a "live" file
system. If the file system had something to trim and the file system
was read-only (or spectator) it would start the trim, but when it starts
the transaction, gfs2_trans_begin returns -EROFS (read-only file system)
and it errors out. However, if the file system was already trimmed so
there's no work to do, it never called gfs2_trans_begin. That code is
bypassed so it never returns the error. Instead, it returns a good
return code with 0 work. All this makes for inconsistent behavior:
The same fstrim command can return -EROFS in one case and 0 in another.
This tripped up xfstests generic/537 which reports the error as:

    +fstrim with unrecovered metadata just ate your filesystem

This patch adds a check for a "live" (iow, active journal, iow, RW)
file system, and if not, returns the error properly.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/gfs2/rgrp.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 0958f76ada6a3..9621badb95995 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -1371,6 +1371,9 @@ int gfs2_fitrim(struct file *filp, void __user *argp)
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
+	if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
+		return -EROFS;
+
 	if (!blk_queue_discard(q))
 		return -EOPNOTSUPP;
 
-- 
2.27.0