This is a note to let you know that I've just added the patch titled
ext4: check iomap type only if ext4_iomap_begin() does not fail
to the 5.10-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:
ext4-check-iomap-type-only-if-ext4_iomap_begin-does-not-fail.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From fa83c34e3e56b3c672af38059e066242655271b1 Mon Sep 17 00:00:00 2001
From: Baokun Li <libaokun1@xxxxxxxxxx>
Date: Fri, 5 May 2023 21:24:29 +0800
Subject: ext4: check iomap type only if ext4_iomap_begin() does not fail
From: Baokun Li <libaokun1@xxxxxxxxxx>
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@xxxxxxxxxx
Reported-by: syzbot+08106c4b7d60702dbc14@xxxxxxxxxxxxxxxxxxxxxxxxx
Link: https://lore.kernel.org/all/00000000000015760b05f9b4eee9@xxxxxxxxxx
Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
Link: https://lore.kernel.org/r/20230505132429.714648-1-libaokun1@xxxxxxxxxx
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ext4/inode.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3564,7 +3564,7 @@ static int ext4_iomap_overwrite_begin(st
*/
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;
}
Patches currently in stable-queue which might be from libaokun1@xxxxxxxxxx are
queue-5.10/ext4-check-iomap-type-only-if-ext4_iomap_begin-does-not-fail.patch
queue-5.10/writeback-cgroup-fix-null-ptr-deref-write-in-bdi_spl.patch
