This is a note to let you know that I've just added the patch titled
gfs2: Don't deref jdesc in evict
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
gfs2-don-t-deref-jdesc-in-evict.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 24cf80fa394c21ccf4498b1945910401961c928c
Author: Bob Peterson <rpeterso@xxxxxxxxxx>
Date: Fri Apr 28 12:07:46 2023 -0400
gfs2: Don't deref jdesc in evict
[ Upstream commit 504a10d9e46bc37b23d0a1ae2f28973c8516e636 ]
On corrupt gfs2 file systems the evict code can try to reference the
journal descriptor structure, jdesc, after it has been freed and set to
NULL. The sequence of events is:
init_journal()
...
fail_jindex:
gfs2_jindex_free(sdp); <------frees journals, sets jdesc = NULL
if (gfs2_holder_initialized(&ji_gh))
gfs2_glock_dq_uninit(&ji_gh);
fail:
iput(sdp->sd_jindex); <--references jdesc in evict_linked_inode
evict()
gfs2_evict_inode()
evict_linked_inode()
ret = gfs2_trans_begin(sdp, 0, sdp->sd_jdesc->jd_blocks);
<------references the now freed/zeroed sd_jdesc pointer.
The call to gfs2_trans_begin is done because the truncate_inode_pages
call can cause gfs2 events that require a transaction, such as removing
journaled data (jdata) blocks from the journal.
This patch fixes the problem by adding a check for sdp->sd_jdesc to
function gfs2_evict_inode. In theory, this should only happen to corrupt
gfs2 file systems, when gfs2 detects the problem, reports it, then tries
to evict all the system inodes it has read in up to that point.
Reported-by: Yang Lan <lanyang0908@xxxxxxxxx>
Signed-off-by: Bob Peterson <rpeterso@xxxxxxxxxx>
Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index 775ac3fb10c67..ca6ee1cbccd50 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -1381,6 +1381,14 @@ static void gfs2_evict_inode(struct inode *inode)
if (inode->i_nlink || sb_rdonly(sb))
goto out;
+ /*
+ * In case of an incomplete mount, gfs2_evict_inode() may be called for
+ * system files without having an active journal to write to. In that
+ * case, skip the filesystem evict.
+ */
+ if (!sdp->sd_jdesc)
+ goto out;
+
gfs2_holder_mark_uninitialized(&gh);
ret = evict_should_delete(inode, &gh);
if (ret == SHOULD_DEFER_EVICTION)
