kernel.git/fs/erofs, branch linux-6.10.y

erofs: handle overlapped pclusters out of crafted images properly

2024-10-04T14:32:32Z

[ Upstream commit 9e2f9d34dd12e6e5b244ec488bcebd0c2d566c50 ] syzbot reported a task hang issue due to a deadlock case where it is waiting for the folio lock of a cached folio that will be used for cache I/Os. After looking into the crafted fuzzed image, I found it's formed with several overlapped big pclusters as below: Ext: logical offset | length : physical offset | length 0: 0.. 16384 | 16384 : 151552.. 167936 | 16384 1: 16384.. 32768 | 16384 : 155648.. 172032 | 16384 2: 32768.. 49152 | 16384 : 537223168.. 537239552 | 16384 ... Here, extent 0/1 are physically overlapped although it's entirely _impossible_ for normal filesystem images generated by mkfs. First, managed folios containing compressed data will be marked as up-to-date and then unlocked immediately (unlike in-place folios) when compressed I/Os are complete. If physical blocks are not submitted in the incremental order, there should be separate BIOs to avoid dependency issues. However, the current code mis-arranges z_erofs_fill_bio_vec() and BIO submission which causes unexpected BIO waits. Second, managed folios will be connected to their own pclusters for efficient inter-queries. However, this is somewhat hard to implement easily if overlapped big pclusters exist. Again, these only appear in fuzzed images so let's simply fall back to temporary short-lived pages for correctness. Additionally, it justifies that referenced managed folios cannot be truncated for now and reverts part of commit 2080ca1ed3e4 ("erofs: tidy up `struct z_erofs_bvec`") for simplicity although it shouldn't be any difference. Reported-by: syzbot+4fc98ed414ae63d1ada2@syzkaller.appspotmail.com Reported-by: syzbot+de04e06b28cfecf2281c@syzkaller.appspotmail.com Reported-by: syzbot+c8c8238b394be4a1087d@syzkaller.appspotmail.com Tested-by: syzbot+4fc98ed414ae63d1ada2@syzkaller.appspotmail.com Closes: https://lore.kernel.org/r/0000000000002fda01061e334873@google.com Fixes: 8e6c8fa9f2e9 ("erofs: enable big pcluster feature") Signed-off-by: Gao Xiang Link: https://lore.kernel.org/r/20240910070847.3356592-1-hsiangkao@linux.alibaba.com Signed-off-by: Sasha Levin

erofs: tidy up `struct z_erofs_bvec`

2024-10-04T14:32:32Z

[ Upstream commit 2080ca1ed3e43233c4e8480c0b9d2840886de01e ] After revisiting the design, I believe `struct z_erofs_bvec` should be page-based instead of folio-based due to the reasons below: - The minimized memory mapping block is a page; - Under the certain circumstances, only temporary pages needs to be used instead of folios since refcount, mapcount for such pages are unnecessary; - Decompressors handle all types of pages including temporary pages, not only folios. When handling `struct z_erofs_bvec`, all folio-related information is now accessed using the page_folio() helper. The final goal of this round adaptation is to eliminate direct accesses to `struct page` in the EROFS codebase, except for some exceptions like `z_erofs_is_shortlived_page()` and `z_erofs_page_is_invalidated()`, which require a new helper to determine the memdesc type of an arbitrary page. Actually large folios of compressed files seem to work now, yet I tend to conduct more tests before officially enabling this for all scenarios. Signed-off-by: Gao Xiang Link: https://lore.kernel.org/r/20240703120051.3653452-4-hsiangkao@linux.alibaba.com Stable-dep-of: 9e2f9d34dd12 ("erofs: handle overlapped pclusters out of crafted images properly") Signed-off-by: Sasha Levin

erofs: fix incorrect symlink detection in fast symlink

2024-10-04T14:32:32Z

[ Upstream commit 9ed50b8231e37b1ae863f5dec8153b98d9f389b4 ] Fast symlink can be used if the on-disk symlink data is stored in the same block as the on-disk inode, so we don’t need to trigger another I/O for symlink data. However, currently fs correction could be reported _incorrectly_ if inode xattrs are too large. In fact, these should be valid images although they cannot be handled as fast symlinks. Many thanks to Colin for reporting this! Reported-by: Colin Walters Reported-by: https://honggfuzz.dev/ Link: https://lore.kernel.org/r/bb2dd430-7de0-47da-ae5b-82ab2dd4d945@app.fastmail.com Fixes: 431339ba9042 ("staging: erofs: add inode operations") [ Note that it's a runtime misbehavior instead of a security issue. ] Signed-off-by: Gao Xiang Link: https://lore.kernel.org/r/20240909031911.1174718-1-hsiangkao@linux.alibaba.com Signed-off-by: Sasha Levin

erofs: fix out-of-bound access when z_erofs_gbuf_growsize() partially fails

2024-09-04T11:29:55Z

commit 0005e01e1e875c5e27130c5e2ed0189749d1e08a upstream. If z_erofs_gbuf_growsize() partially fails on a global buffer due to memory allocation failure or fault injection (as reported by syzbot [1]), new pages need to be freed by comparing to the existing pages to avoid memory leaks. However, the old gbuf->pages[] array may not be large enough, which can lead to null-ptr-deref or out-of-bound access. Fix this by checking against gbuf->nrpages in advance. [1] https://lore.kernel.org/r/000000000000f7b96e062018c6e3@google.com Reported-by: syzbot+242ee56aaa9585553766@syzkaller.appspotmail.com Fixes: d6db47e571dc ("erofs: do not use pagepool in z_erofs_gbuf_growsize()") Cc: # 6.10+ Reviewed-by: Chunhai Guo Reviewed-by: Sandeep Dhavale Signed-off-by: Gao Xiang Link: https://lore.kernel.org/r/20240820085619.1375963-1-hsiangkao@linux.alibaba.com Signed-off-by: Greg Kroah-Hartman

erofs: fix race in z_erofs_get_gbuf()

2024-08-03T07:00:45Z

commit 7dc5537c3f8be87e005f0844a7626c987914f8fd upstream. In z_erofs_get_gbuf(), the current task may be migrated to another CPU between `z_erofs_gbuf_id()` and `spin_lock(&gbuf->lock)`. Therefore, z_erofs_put_gbuf() will trigger the following issue which was found by stress test: <2>[772156.434168] kernel BUG at fs/erofs/zutil.c:58! .. <4>[772156.435007] <4>[772156.439237] CPU: 0 PID: 3078 Comm: stress Kdump: loaded Tainted: G E 6.10.0-rc7+ #2 <4>[772156.439239] Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 1.0.0 01/01/2017 <4>[772156.439241] pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) <4>[772156.439243] pc : z_erofs_put_gbuf+0x64/0x70 [erofs] <4>[772156.439252] lr : z_erofs_lz4_decompress+0x600/0x6a0 [erofs] .. <6>[772156.445958] stress (3127): drop_caches: 1 <4>[772156.446120] Call trace: <4>[772156.446121] z_erofs_put_gbuf+0x64/0x70 [erofs] <4>[772156.446761] z_erofs_lz4_decompress+0x600/0x6a0 [erofs] <4>[772156.446897] z_erofs_decompress_queue+0x740/0xa10 [erofs] <4>[772156.447036] z_erofs_runqueue+0x428/0x8c0 [erofs] <4>[772156.447160] z_erofs_readahead+0x224/0x390 [erofs] .. Fixes: f36f3010f676 ("erofs: rename per-CPU buffers to global buffer pool and make it configurable") Cc: # 6.10+ Reviewed-by: Chunhai Guo Reviewed-by: Sandeep Dhavale Reviewed-by: Chao Yu Signed-off-by: Gao Xiang Link: https://lore.kernel.org/r/20240722035110.3456740-1-hsiangkao@linux.alibaba.com Signed-off-by: Greg Kroah-Hartman

erofs: ensure m_llen is reset to 0 if metadata is invalid

2024-06-30T02:54:28Z

Sometimes, the on-disk metadata might be invalid due to user interrupts, storage failures, or other unknown causes. In that case, z_erofs_map_blocks_iter() may still return a valid m_llen while other fields remain invalid (e.g., m_plen can be 0). Due to the return value of z_erofs_scan_folio() in some path will be ignored on purpose, the following z_erofs_scan_folio() could then use the invalid value by accident. Let's reset m_llen to 0 to prevent this. Link: https://lore.kernel.org/r/20240629185743.2819229-1-hsiangkao@linux.alibaba.com Signed-off-by: Gao Xiang

erofs: convert to use super_set_uuid to support for FS_IOC_GETFSUUID

2024-06-26T09:02:28Z

FS_IOC_GETFSUUID ioctl exposes the uuid of a filesystem. To support the ioctl, init sb->s_uuid with super_set_uuid(). Signed-off-by: Huang Xiaojia Reviewed-by: Gao Xiang Reviewed-by: Chao Yu Link: https://lore.kernel.org/r/20240624063704.2476070-1-huangxiaojia2@huawei.com Signed-off-by: Gao Xiang

erofs: fix possible memory leak in z_erofs_gbuf_exit()

2024-06-26T09:02:15Z

Because we incorrectly reused of variable `i` in `z_erofs_gbuf_exit()` for inner loop, we may exit early from outer loop resulting in memory leak. Fix this by using separate variable for iterating through inner loop. Fixes: f36f3010f676 ("erofs: rename per-CPU buffers to global buffer pool and make it configurable") Signed-off-by: Sandeep Dhavale Reviewed-by: Gao Xiang Reviewed-by: Chao Yu Link: https://lore.kernel.org/r/20240624220206.3373197-1-dhavale@google.com Signed-off-by: Gao Xiang

Merge tag 'erofs-for-6.10-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs

2024-05-24T16:31:50Z

Pull more erofs updates from Gao Xiang: "The main ones are metadata API conversion to byte offsets by Al Viro. Another patch gets rid of unnecessary memory allocation out of DEFLATE decompressor. The remaining one is a trivial cleanup. - Convert metadata APIs to byte offsets - Avoid allocating DEFLATE streams unnecessarily - Some erofs_show_options() cleanup" * tag 'erofs-for-6.10-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs: erofs: avoid allocating DEFLATE streams before mounting z_erofs_pcluster_begin(): don't bother with rounding position down erofs: don't round offset down for erofs_read_metabuf() erofs: don't align offset for erofs_read_metabuf() (simple cases) erofs: mechanically convert erofs_read_metabuf() to offsets erofs: clean up erofs_show_options()

Merge tag 'pull-bd_inode-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2024-05-21T16:51:42Z

Pull bdev bd_inode updates from Al Viro: "Replacement of bdev->bd_inode with sane(r) set of primitives by me and Yu Kuai" * tag 'pull-bd_inode-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: RIP ->bd_inode dasd_format(): killing the last remaining user of ->bd_inode nilfs_attach_log_writer(): use ->bd_mapping->host instead of ->bd_inode block/bdev.c: use the knowledge of inode/bdev coallocation gfs2: more obvious initializations of mapping->host fs/buffer.c: massage the remaining users of ->bd_inode to ->bd_mapping blk_ioctl_{discard,zeroout}(): we only want ->bd_inode->i_mapping here... grow_dev_folio(): we only want ->bd_inode->i_mapping there use ->bd_mapping instead of ->bd_inode->i_mapping block_device: add a pointer to struct address_space (page cache of bdev) missing helpers: bdev_unhash(), bdev_drop() block: move two helpers into bdev.c block2mtd: prevent direct access of bd_inode dm-vdo: use bdev_nr_bytes(bdev) instead of i_size_read(bdev->bd_inode) blkdev_write_iter(): saner way to get inode and bdev bcachefs: remove dead function bdev_sectors() ext4: remove block_device_ejected() erofs_buf: store address_space instead of inode erofs: switch erofs_bread() to passing offset instead of block number