From f7dd5f0807d822615a8ddbceb711c343ac8eaab2 Mon Sep 17 00:00:00 2001
From: Jiri Slaby <jslaby@suse.cz>
Date: May 17 2023 19:16:07 +0000
Subject: ext4: check iomap type only if ext4_iomap_begin() does not fail

(bsc#1012628).

---

diff --git a/patches.kernel.org/6.3.3-230-ext4-check-iomap-type-only-if-ext4_iomap_begin-.patch b/patches.kernel.org/6.3.3-230-ext4-check-iomap-type-only-if-ext4_iomap_begin-.patch
new file mode 100644
index 0000000..7e16fcb
--- /dev/null
+++ b/patches.kernel.org/6.3.3-230-ext4-check-iomap-type-only-if-ext4_iomap_begin-.patch
@@ -0,0 +1,46 @@
+From: Baokun Li <libaokun1@huawei.com>
+Date: Fri, 5 May 2023 21:24:29 +0800
+Subject: [PATCH] ext4: check iomap type only if ext4_iomap_begin() does not
+ fail
+References: bsc#1012628
+Patch-mainline: 6.3.3
+Git-commit: fa83c34e3e56b3c672af38059e066242655271b1
+
+commit fa83c34e3e56b3c672af38059e066242655271b1 upstream.
+
+When ext4_iomap_overwrite_begin() calls ext4_iomap_begin() map blocks may
+fail for some reason (e.g. memory allocation failure, bare disk write), and
+later because "iomap->type ! = IOMAP_MAPPED" triggers WARN_ON(). When ext4
+iomap_begin() returns an error, it is normal that the type of iomap->type
+may not match the expectation. Therefore, we only determine if iomap->type
+is as expected when ext4_iomap_begin() is executed successfully.
+
+Cc: stable@kernel.org
+Reported-by: syzbot+08106c4b7d60702dbc14@syzkaller.appspotmail.com
+Link: https://lore.kernel.org/all/00000000000015760b05f9b4eee9@google.com
+Signed-off-by: Baokun Li <libaokun1@huawei.com>
+Reviewed-by: Jan Kara <jack@suse.cz>
+Link: https://lore.kernel.org/r/20230505132429.714648-1-libaokun1@huawei.com
+Signed-off-by: Theodore Ts'o <tytso@mit.edu>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Signed-off-by: Jiri Slaby <jslaby@suse.cz>
+---
+ fs/ext4/inode.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
+index 87d01f1c..145ea24d 100644
+--- a/fs/ext4/inode.c
++++ b/fs/ext4/inode.c
+@@ -3576,7 +3576,7 @@ static int ext4_iomap_overwrite_begin(struct inode *inode, loff_t offset,
+ 	 */
+ 	flags &= ~IOMAP_WRITE;
+ 	ret = ext4_iomap_begin(inode, offset, length, flags, iomap, srcmap);
+-	WARN_ON_ONCE(iomap->type != IOMAP_MAPPED);
++	WARN_ON_ONCE(!ret && iomap->type != IOMAP_MAPPED);
+ 	return ret;
+ }
+ 
+-- 
+2.35.3
+
diff --git a/series.conf b/series.conf
index 97f5994..76f54c8 100644
--- a/series.conf
+++ b/series.conf
@@ -963,6 +963,7 @@
 	patches.kernel.org/6.3.3-227-ext4-avoid-a-potential-slab-out-of-bounds-in-ex.patch
 	patches.kernel.org/6.3.3-228-ext4-fix-data-races-when-using-cached-status-ex.patch
 	patches.kernel.org/6.3.3-229-ext4-avoid-deadlock-in-fs-reclaim-with-page-wri.patch
+	patches.kernel.org/6.3.3-230-ext4-check-iomap-type-only-if-ext4_iomap_begin-.patch
 
 	########################################################
 	# Build fixes that apply to the vanilla kernel too.