From: Jan Kara <jack@suse.cz>
Date: Mon, 11 Mar 2019 14:04:18 +0000 (+0100)
Subject: udf: Fix crash on IO error during truncate
X-Git-Tag: v3.18.138~50
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=824289e104f97ed08fd77fcf82922a7cbe547188;p=thirdparty%2Fkernel%2Fstable.git

udf: Fix crash on IO error during truncate

commit d3ca4651d05c0ff7259d087d8c949bcf3e14fb46 upstream.

When truncate(2) hits IO error when reading indirect extent block the
code just bugs with:

kernel BUG at linux-4.15.0/fs/udf/truncate.c:249!
...

Fix the problem by bailing out cleanly in case of IO error.

CC: stable@vger.kernel.org
Reported-by: jean-luc malet <jeanluc.malet@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/udf/truncate.c b/fs/udf/truncate.c
index 8a9657d7f7c68..8df2632a29668 100644
--- a/fs/udf/truncate.c
+++ b/fs/udf/truncate.c
@@ -261,6 +261,9 @@ void udf_truncate_extents(struct inode *inode)
 			epos.block = eloc;
 			epos.bh = udf_tread(sb,
 					udf_get_lb_pblock(sb, &eloc, 0));
+			/* Error reading indirect block? */
+			if (!epos.bh)
+				return;
 			if (elen)
 				indirect_ext_len =
 					(elen + sb->s_blocksize - 1) >>