From: Chao Yu chao@kernel.org
[ 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@kernel.org Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/f2fs/data.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index a28d05895f5c7..75e59e7016590 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -873,6 +873,8 @@ 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; @@ -2899,7 +2901,8 @@ 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; }