kernel/linux.git/fs/erofs, branch v6.18.33

erofs: unify lcn as u64 for 32-bit platforms

2026-05-23T11:06:58+00:00

[ Upstream commit 2d8c7edcb661812249469f4a5b62e9339118846f ] As sashiko reported [1], `lcn` was typed as `unsigned long` (or `unsigned int` sometimes), which is only 32 bits wide on 32-bit platforms, which causes `(lcn << lclusterbits)` to be truncated at 4 GiB. In order to consolidate the logic, just use `u64` consistently around the codebase. [1] https://sashiko.dev/r/20260420034612.1899973-1-hsiangkao%40linux.alibaba.com Fixes: 152a333a5895 ("staging: erofs: add compacted compression indexes support") Signed-off-by: Gao Xiang Signed-off-by: Sasha Levin

erofs: handle 48-bit blocks/uniaddr for extra devices

2026-05-23T11:06:23+00:00

[ Upstream commit 63c2f06198ca7513433f1c92f2c654869d72417e ] erofs_init_device() only reads blocks_lo and uniaddr_lo from the on-disk device slot, ignoring blocks_hi and uniaddr_hi that were introduced alongside the 48-bit block addressing feature. For the primary device (dif0), erofs_read_superblock() already handles this correctly by combining blocks_lo with blocks_hi when 48-bit layout is enabled. But the same logic was not applied to extra devices. With a 48-bit EROFS image using extra devices whose uniaddr or blocks exceed 32-bit range, the truncated values cause erofs_map_dev() to compute wrong physical addresses, leading to silent data corruption. Fix this by reading blocks_hi and uniaddr_hi in erofs_init_device() when 48-bit layout is enabled, consistent with the primary device handling. Also fix the erofs_deviceslot on-disk definition where blocks_hi was incorrectly declared as __le32 instead of __le16. Fixes: 61ba89b57905 ("erofs: add 48-bit block addressing on-disk support") Suggested-by: Gao Xiang Signed-off-by: Zhan Xusheng Reviewed-by: Gao Xiang Signed-off-by: Gao Xiang Signed-off-by: Sasha Levin

erofs: include the trailing NUL in FS_IOC_GETFSLABEL

2026-05-23T11:06:23+00:00

[ Upstream commit d6250d49da4d8f11afc0d8991c84e0307949f92e ] erofs_ioctl_get_volume_label() passes strlen(sbi->volume_name) as the length to copy_to_user(), which copies the label string without the trailing NUL byte. Since FS_IOC_GETFSLABEL callers expect a NUL-terminated string in the FSLABEL_MAX-sized buffer and may not pre-zero the buffer, this can cause userspace to read past the label into uninitialised stack memory. Fix this by using strlen() + 1 to include the NUL terminator, consistent with how ext4 and xfs implement FS_IOC_GETFSLABEL. Signed-off-by: Zhan Xusheng Fixes: 1cf12c717741 ("erofs: Add support for FS_IOC_GETFSLABEL") Reviewed-by: Gao Xiang Reviewed-by: Chunhai Guo Signed-off-by: Gao Xiang Signed-off-by: Sasha Levin

erofs: fix unsigned underflow in z_erofs_lz4_handle_overlap()

2026-05-14T13:30:25+00:00

[ Upstream commit 21e161de2dc660b1bb70ef5b156ab8e6e1cca3ab ] Some crafted images can have illegal (!partial_decoding && m_llen < m_plen) extents, and the LZ4 inplace decompression path can be wrongly hit, but it cannot handle (outpages < inpages) properly: "outpages - inpages" wraps to a large value and the subsequent rq->out[] access reads past the decompressed_pages array. However, such crafted cases can correctly result in a corruption report in the normal LZ4 non-inplace path. Let's add an additional check to fix this for backporting. Reproducible image (base64-encoded gzipped blob): H4sIAJGR12kCA+3SPUoDQRgG4MkmkkZk8QRbRFIIi9hbpEjrHQI5ghfwCN5BLCzTGtLbBI+g dilSJo1CnIm7GEXFxhT6PDDwfrs73/ywIQD/1ePD4r7Ou6ETsrq4mu7XcWfj++Pb58nJU/9i PNtbjhan04/9GtX4qVYc814WDqt6FaX5s+ZwXXeq52lndT6IuVvlblytLMvh4Gzwaf90nsvz 2DF/21+20T/ldgp5s1jXRaN4t/8izsy/OUB6e/Qa79r+JwAAAAAAAL52vQVuGQAAAP6+my1w ywAAAAAAAADwu14ATsEYtgBQAAA= $ mount -t erofs -o cache_strategy=disabled foo.erofs /mnt $ dd if=/mnt/data of=/dev/null bs=4096 count=1 Fixes: 598162d05080 ("erofs: support decompress big pcluster for lz4 backend") Reported-by: Yuhao Jiang Cc: stable@vger.kernel.org Signed-off-by: Junrui Luo Reviewed-by: Gao Xiang Signed-off-by: Gao Xiang Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

erofs: tidy up z_erofs_lz4_handle_overlap()

2026-05-14T13:30:25+00:00

[ Upstream commit 9ae77198d4815c63fc8ebacc659c71d150d1e51b ] - Add some useful comments to explain inplace I/Os and decompression; - Rearrange the code to get rid of one unnecessary goto. Reviewed-by: Chao Yu Signed-off-by: Gao Xiang Stable-dep-of: 21e161de2dc6 ("erofs: fix unsigned underflow in z_erofs_lz4_handle_overlap()") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

erofs: fix the out-of-bounds nameoff handling for trailing dirents

2026-05-07T04:11:38+00:00

commit d18a3b5d337fa412a38e776e6b4b857a58836575 upstream. Currently we already have boundary-checks for nameoffs, but the trailing dirents are special since the namelens are calculated with strnlen() with unchecked nameoffs. If a crafted EROFS has a trailing dirent with nameoff >= maxsize, maxsize - nameoff can underflow, causing strnlen() to read past the directory block. nameoff0 should also be verified to be a multiple of `sizeof(struct erofs_dirent)` as well [1]. [1] https://sashiko.dev/#/patchset/20260416063511.3173774-1-hsiangkao%40linux.alibaba.com Fixes: 3aa8ec716e52 ("staging: erofs: add directory operations") Fixes: 33bac912840f ("staging: erofs: keep corrupted fs from crashing kernel in erofs_readdir()") Reported-by: Yuhao Jiang Reported-by: Junrui Luo Closes: https://lore.kernel.org/r/A0FD7E0F-7558-49B0-8BC8-EB1ECDB2479A@outlook.com Cc: stable@vger.kernel.org Signed-off-by: Gao Xiang Reviewed-by: Chao Yu Signed-off-by: Greg Kroah-Hartman

erofs: add GFP_NOIO in the bio completion if needed

2026-04-02T11:23:20+00:00

commit c23df30915f83e7257c8625b690a1cece94142a0 upstream. The bio completion path in the process context (e.g. dm-verity) will directly call into decompression rather than trigger another workqueue context for minimal scheduling latencies, which can then call vm_map_ram() with GFP_KERNEL. Due to insufficient memory, vm_map_ram() may generate memory swapping I/O, which can cause submit_bio_wait to deadlock in some scenarios. Trimmed down the call stack, as follows: f2fs_submit_read_io submit_bio //bio_list is initialized. mmc_blk_mq_recovery z_erofs_endio vm_map_ram __pte_alloc_kernel __alloc_pages_direct_reclaim shrink_folio_list __swap_writepage submit_bio_wait //bio_list is non-NULL, hang!!! Use memalloc_noio_{save,restore}() to wrap up this path. Reviewed-by: Gao Xiang Signed-off-by: Jiucheng Xu Reviewed-by: Chao Yu Signed-off-by: Gao Xiang Signed-off-by: Greg Kroah-Hartman

erofs: set fileio bio failed in short read case

2026-04-02T11:23:03+00:00

[ Upstream commit eade54040384f54b7fb330e4b0975c5734850b3c ] For file-backed mount, IO requests are handled by vfs_iocb_iter_read(). However, it can be interrupted by SIGKILL, returning the number of bytes actually copied. Unused folios in bio are unexpectedly marked as uptodate. vfs_read filemap_read filemap_get_pages filemap_readahead erofs_fileio_readahead erofs_fileio_rq_submit vfs_iocb_iter_read filemap_read filemap_get_pages <= detect signal erofs_fileio_ki_complete <= set all folios uptodate This patch addresses this by setting short read bio with an error directly. Fixes: bc804a8d7e86 ("erofs: handle end of filesystem properly for file-backed mounts") Reported-by: chenguanyou Signed-off-by: Yunlei He Signed-off-by: Sheng Yong Reviewed-by: Gao Xiang Reviewed-by: Chao Yu Signed-off-by: Gao Xiang Signed-off-by: Sasha Levin

erofs: fix incorrect early exits in volume label handling

2026-03-04T12:21:13+00:00

[ Upstream commit 3afa4da38802a4cba1c23848a32284e7e57b831b ] Crafted EROFS images containing valid volume labels can trigger incorrect early returns, leading to folio reference leaks. However, this does not cause system crashes or other severe issues. Fixes: 1cf12c717741 ("erofs: Add support for FS_IOC_GETFSLABEL") Cc: stable@kernel.org Reviewed-by: Hongbo Li Reviewed-by: Chao Yu Signed-off-by: Gao Xiang Signed-off-by: Sasha Levin

erofs: fix incorrect early exits for invalid metabox-enabled images

2026-03-04T12:21:13+00:00

[ Upstream commit 643575d5a4f24b23b0c54aa20aa74a4abed8ff5e ] Crafted EROFS images with metadata compression enabled can trigger incorrect early returns, leading to folio reference leaks. However, this does not cause system crashes or other severe issues. Fixes: 414091322c63 ("erofs: implement metadata compression") Cc: stable@kernel.org Reviewed-by: Hongbo Li Reviewed-by: Chao Yu Signed-off-by: Gao Xiang Signed-off-by: Sasha Levin