kernel/linux.git/fs/erofs, branch v5.10.257

minmax: add a few more MIN_T/MAX_T users

2025-10-29T13:01:16+00:00

[ Upstream commit 4477b39c32fdc03363affef4b11d48391e6dc9ff ] Commit 3a7e02c040b1 ("minmax: avoid overly complicated constant expressions in VM code") added the simpler MIN_T/MAX_T macros in order to avoid some excessive expansion from the rather complicated regular min/max macros. The complexity of those macros stems from two issues: (a) trying to use them in situations that require a C constant expression (in static initializers and for array sizes) (b) the type sanity checking and MIN_T/MAX_T avoids both of these issues. Now, in the whole (long) discussion about all this, it was pointed out that the whole type sanity checking is entirely unnecessary for min_t/max_t which get a fixed type that the comparison is done in. But that still leaves min_t/max_t unnecessarily complicated due to worries about the C constant expression case. However, it turns out that there really aren't very many cases that use min_t/max_t for this, and we can just force-convert those. This does exactly that. Which in turn will then allow for much simpler implementations of min_t()/max_t(). All the usual "macros in all upper case will evaluate the arguments multiple times" rules apply. We should do all the same things for the regular min/max() vs MIN/MAX() cases, but that has the added complexity of various drivers defining their own local versions of MIN/MAX, so that needs another level of fixes first. Link: https://lore.kernel.org/all/b47fad1d0cf8449886ad148f8c013dae@AcuMS.aculab.com/ Cc: David Laight Cc: Lorenzo Stoakes Signed-off-by: Linus Torvalds Signed-off-by: Eliav Farber Signed-off-by: Greg Kroah-Hartman

erofs: fix incorrect symlink detection in fast symlink

2025-01-09T12:24:51+00:00

commit 9ed50b8231e37b1ae863f5dec8153b98d9f389b4 upstream. 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. ] Link: https://lore.kernel.org/r/20240909031911.1174718-1-hsiangkao@linux.alibaba.com [ Gao Xiang: fix 5.10.y build warning due to `check_add_overflow`. ] Signed-off-by: Gao Xiang Signed-off-by: Sasha Levin

erofs: fix order >= MAX_ORDER warning due to crafted negative i_size

2025-01-09T12:24:51+00:00

commit 1dd73601a1cba37a0ed5f89a8662c90191df5873 upstream. As syzbot reported [1], the root cause is that i_size field is a signed type, and negative i_size is also less than EROFS_BLKSIZ. As a consequence, it's handled as fast symlink unexpectedly. Let's fall back to the generic path to deal with such unusual i_size. [1] https://lore.kernel.org/r/000000000000ac8efa05e7feaa1f@google.com Reported-by: syzbot+f966c13b1b4fc0403b19@syzkaller.appspotmail.com Fixes: 431339ba9042 ("staging: erofs: add inode operations") Reviewed-by: Yue Hu Link: https://lore.kernel.org/r/20220909023948.28925-1-hsiangkao@linux.alibaba.com Signed-off-by: Gao Xiang Signed-off-by: Sasha Levin

erofs: fix lz4 inplace decompression

2024-03-01T12:16:48+00:00

commit 3c12466b6b7bf1e56f9b32c366a3d83d87afb4de upstream. Currently EROFS can map another compressed buffer for inplace decompression, that was used to handle the cases that some pages of compressed data are actually not in-place I/O. However, like most simple LZ77 algorithms, LZ4 expects the compressed data is arranged at the end of the decompressed buffer and it explicitly uses memmove() to handle overlapping: __________________________________________________________ |_ direction of decompression --> ____ |_ compressed data _| Although EROFS arranges compressed data like this, it typically maps two individual virtual buffers so the relative order is uncertain. Previously, it was hardly observed since LZ4 only uses memmove() for short overlapped literals and x86/arm64 memmove implementations seem to completely cover it up and they don't have this issue. Juhyung reported that EROFS data corruption can be found on a new Intel x86 processor. After some analysis, it seems that recent x86 processors with the new FSRM feature expose this issue with "rep movsb". Let's strictly use the decompressed buffer for lz4 inplace decompression for now. Later, as an useful improvement, we could try to tie up these two buffers together in the correct order. Reported-and-tested-by: Juhyung Park Closes: https://lore.kernel.org/r/CAD14+f2AVKf8Fa2OO1aAUdDNTDsVzzR6ctU_oJSmTyd6zSYR2Q@mail.gmail.com Fixes: 0ffd71bcc3a0 ("staging: erofs: introduce LZ4 decompression inplace") Fixes: 598162d05080 ("erofs: support decompress big pcluster for lz4 backend") Cc: stable # 5.4+ Tested-by: Yifan Zhao Signed-off-by: Gao Xiang Link: https://lore.kernel.org/r/20231206045534.3920847-1-hsiangkao@linux.alibaba.com Signed-off-by: Greg Kroah-Hartman

erofs: ensure that the post-EOF tails are all zeroed

2023-09-19T10:20:02+00:00

commit e4c1cf523d820730a86cae2c6d55924833b6f7ac upstream. This was accidentally fixed up in commit e4c1cf523d82 but we can't take the full change due to other dependancy issues, so here is just the actual bugfix that is needed. [Background] keltargw reported an issue [1] that with mmaped I/Os, sometimes the tail of the last page (after file ends) is not filled with zeroes. The root cause is that such tail page could be wrongly selected for inplace I/Os so the zeroed part will then be filled with compressed data instead of zeroes. A simple fix is to avoid doing inplace I/Os for such tail parts, actually that was already fixed upstream in commit e4c1cf523d82 ("erofs: tidy up z_erofs_do_read_page()") by accident. [1] https://lore.kernel.org/r/3ad8b469-25db-a297-21f9-75db2d6ad224@linux.alibaba.com Reported-by: keltargw Fixes: 3883a79abd02 ("staging: erofs: introduce VLE decompression support") Signed-off-by: Gao Xiang Signed-off-by: Greg Kroah-Hartman

erofs: fix compact 4B support for 16k block size

2023-07-27T06:44:26+00:00

commit 001b8ccd0650727e54ec16ef72bf1b8eeab7168e upstream. In compact 4B, two adjacent lclusters are packed together as a unit to form on-disk indexes for effective random access, as below: (amortized = 4, vcnt = 2) _____________________________________________ |___@_____ encoded bits __________|_ blkaddr _| 0 . amortized * vcnt = 8 . . . . amortized * vcnt - 4 = 4 . . .____________________________. |_type (2 bits)_|_clusterofs_| Therefore, encoded bits for each pack are 32 bits (4 bytes). IOWs, since each lcluster can get 16 bits for its type and clusterofs, the maximum supported lclustersize for compact 4B format is 16k (14 bits). Fix this to enable compact 4B format for 16k lclusters (blocks), which is tested on an arm64 server with 16k page size. Fixes: 152a333a5895 ("staging: erofs: add compacted compression indexes support") Signed-off-by: Gao Xiang Link: https://lore.kernel.org/r/20230601112341.56960-1-hsiangkao@linux.alibaba.com Signed-off-by: Greg Kroah-Hartman

erofs: avoid infinite loop in z_erofs_do_read_page() when reading beyond EOF

2023-07-27T06:44:23+00:00

[ Upstream commit 8191213a5835b0317c5e4d0d337ae1ae00c75253 ] z_erofs_do_read_page() may loop infinitely due to the inappropriate truncation in the below statement. Since the offset is 64 bits and min_t() truncates the result to 32 bits. The solution is to replace unsigned int with a 64-bit type, such as erofs_off_t. cur = end - min_t(unsigned int, offset + end - map->m_la, end); - For example: - offset = 0x400160000 - end = 0x370 - map->m_la = 0x160370 - offset + end - map->m_la = 0x400000000 - offset + end - map->m_la = 0x00000000 (truncated as unsigned int) - Expected result: - cur = 0 - Actual result: - cur = 0x370 Signed-off-by: Chunhai Guo Fixes: 3883a79abd02 ("staging: erofs: introduce VLE decompression support") Reviewed-by: Gao Xiang Reviewed-by: Chao Yu Link: https://lore.kernel.org/r/20230710093410.44071-1-guochunhai@vivo.com Signed-off-by: Gao Xiang Signed-off-by: Sasha Levin

erofs: fix potential overflow calculating xattr_isize

2023-05-17T09:47:38+00:00

[ Upstream commit 1b3567a1969b26f709d82a874498c0754ea841c3 ] Given on-disk i_xattr_icount is 16 bits and xattr_isize is calculated from i_xattr_icount multiplying 4, xattr_isize has a theoretical maximum of 256K (64K * 4). Thus declare xattr_isize as unsigned int to avoid the potential overflow. Fixes: bfb8674dc044 ("staging: erofs: add erofs in-memory stuffs") Signed-off-by: Jingbo Xu Reviewed-by: Gao Xiang Reviewed-by: Chao Yu Link: https://lore.kernel.org/r/20230414061810.6479-1-jefflexu@linux.alibaba.com Signed-off-by: Gao Xiang Signed-off-by: Sasha Levin

erofs: stop parsing non-compact HEAD index if clusterofs is invalid

2023-05-17T09:47:38+00:00

[ Upstream commit cc4efd3dd2ac9f89143e5d881609747ecff04164 ] Syzbot generated a crafted image [1] with a non-compact HEAD index of clusterofs 33024 while valid numbers should be 0 ~ lclustersize-1, which causes the following unexpected behavior as below: BUG: unable to handle page fault for address: fffff52101a3fff9 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 23ffed067 P4D 23ffed067 PUD 0 Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 4398 Comm: kworker/u5:1 Not tainted 6.3.0-rc6-syzkaller-g09a9639e56c0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023 Workqueue: erofs_worker z_erofs_decompressqueue_work RIP: 0010:z_erofs_decompress_queue+0xb7e/0x2b40 ... Call Trace: z_erofs_decompressqueue_work+0x99/0xe0 process_one_work+0x8f6/0x1170 worker_thread+0xa63/0x1210 kthread+0x270/0x300 ret_from_fork+0x1f/0x30 Note that normal images or images using compact indexes are not impacted. Let's fix this now. [1] https://lore.kernel.org/r/000000000000ec75b005ee97fbaa@google.com Reported-and-tested-by: syzbot+aafb3f37cfeb6534c4ac@syzkaller.appspotmail.com Fixes: 02827e1796b3 ("staging: erofs: add erofs_map_blocks_iter") Fixes: 152a333a5895 ("staging: erofs: add compacted compression indexes support") Signed-off-by: Gao Xiang Reviewed-by: Chao Yu Link: https://lore.kernel.org/r/20230410173714.104604-1-hsiangkao@linux.alibaba.com Signed-off-by: Sasha Levin

erofs: avoid consecutive detection for Highmem memory

2022-08-21T13:15:35+00:00

[ Upstream commit 448b5a1548d87c246c3d0c3df8480d3c6eb6c11a ] Currently, vmap()s are avoided if physical addresses are consecutive for decompressed buffers. I observed that is very common for 4KiB pclusters since the numbers of decompressed pages are almost 2 or 3. However, such detection doesn't work for Highmem pages on 32-bit machines, let's fix it now. Reported-by: Liu Jinbao Fixes: 7fc45dbc938a ("staging: erofs: introduce generic decompression backend") Link: https://lore.kernel.org/r/20220708101001.21242-1-hsiangkao@linux.alibaba.com Signed-off-by: Gao Xiang Signed-off-by: Sasha Levin