This is a note to let you know that I've just added the patch titled
f2fs: fix to avoid use-after-free for cached IPU bio
to the 6.1-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:
f2fs-fix-to-avoid-use-after-free-for-cached-ipu-bio.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 5a8984ed731feadf616797c20ed6e09b9cf55b89
Author: Chao Yu <chao@xxxxxxxxxx>
Date: Mon Apr 10 10:14:02 2023 +0800
f2fs: fix to avoid use-after-free for cached IPU bio
[ Upstream commit 5cdb422c839134273866208dad5360835ddb9794 ]
xfstest generic/019 reports a bug:
kernel BUG at mm/filemap.c:1619!
RIP: 0010:folio_end_writeback+0x8a/0x90
Call Trace:
end_page_writeback+0x1c/0x60
f2fs_write_end_io+0x199/0x420
bio_endio+0x104/0x180
submit_bio_noacct+0xa5/0x510
submit_bio+0x48/0x80
f2fs_submit_write_bio+0x35/0x300
f2fs_submit_merged_ipu_write+0x2a0/0x2b0
f2fs_write_single_data_page+0x838/0x8b0
f2fs_write_cache_pages+0x379/0xa30
f2fs_write_data_pages+0x30c/0x340
do_writepages+0xd8/0x1b0
__writeback_single_inode+0x44/0x370
writeback_sb_inodes+0x233/0x4d0
__writeback_inodes_wb+0x56/0xf0
wb_writeback+0x1dd/0x2d0
wb_workfn+0x367/0x4a0
process_one_work+0x21d/0x430
worker_thread+0x4e/0x3c0
kthread+0x103/0x130
ret_from_fork+0x2c/0x50
The root cause is: after cp_error is set, f2fs_submit_merged_ipu_write()
in f2fs_write_single_data_page() tries to flush IPU bio in cache, however
f2fs_submit_merged_ipu_write() missed to check validity of @bio parameter,
result in submitting random cached bio which belong to other IO context,
then it will cause use-after-free issue, fix it by adding additional
validity check.
Fixes: 0b20fcec8651 ("f2fs: cache global IPU bio")
Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index f92899bfcbd5e..770a606eb3f6a 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -858,6 +858,8 @@ void f2fs_submit_merged_ipu_write(struct f2fs_sb_info *sbi,
bool found = false;
struct bio *target = bio ? *bio : NULL;
+ f2fs_bug_on(sbi, !target && !page);
+
for (temp = HOT; temp < NR_TEMP_TYPE && !found; temp++) {
struct f2fs_bio_info *io = sbi->write_io[DATA] + temp;
struct list_head *head = &io->bio_list;
@@ -2886,7 +2888,8 @@ int f2fs_write_single_data_page(struct page *page, int *submitted,
if (unlikely(f2fs_cp_error(sbi))) {
f2fs_submit_merged_write(sbi, DATA);
- f2fs_submit_merged_ipu_write(sbi, bio, NULL);
+ if (bio && *bio)
+ f2fs_submit_merged_ipu_write(sbi, bio, NULL);
submitted = NULL;
}
