kernel/linux.git/fs/erofs, branch v7.0.11

erofs: fix metabuf leak in inode xattr initialization

2026-06-01T15:54:50+00:00

[ Upstream commit 79b09c54c6563df9846ca3094bcfd72082c3e1d7 ] commit bb88e8da0025 ("erofs: use meta buffers for xattr operations") converted xattr operations to use on-stack erofs_buf instances. erofs_init_inode_xattrs() uses such a metabuf while reading the inline xattr header and shared xattr id array. Some error paths after erofs_read_metabuf() leave through out_unlock without dropping the metabuf, so the folio reference can leak. Consolidate the cleanup at out_unlock. erofs_put_metabuf() is a no-op if no folio has been acquired, and this keeps all paths after taking EROFS_I_BL_XATTR_BIT covered by a single cleanup site. Fixes: bb88e8da0025 ("erofs: use meta buffers for xattr operations") Signed-off-by: Jia Zhu Reviewed-by: Gao Xiang Fixes: bb88e8da0025 ("erofs: use meta buffers for xattr operations") Signed-off-by: Gao Xiang Signed-off-by: Sasha Levin

erofs: harden h_shared_count in erofs_init_inode_xattrs()

2026-06-01T15:54:50+00:00

[ Upstream commit 6a01f5478d208544c8ba5ddbd674ea660f1b7047 ] `u8 h_shared_count` indicates the shared xattr count of an inode. It is read from the on-disk xattr ibody header, which should be corrupted if the size of the shared xattr array exceeds the space available in `xattr_isize`. It does not cause harmful consequence (e.g. crashes), since the image is already considered corrupted, it indeed results in the silent processing of garbage metadata. Let's harden it to report -EFSCORRUPTED earlier. Signed-off-by: Utkal Singh Reviewed-by: Gao Xiang Reviewed-by: Chao Yu Signed-off-by: Gao Xiang Stable-dep-of: 79b09c54c656 ("erofs: fix metabuf leak in inode xattr initialization") Signed-off-by: Sasha Levin

erofs: fix managed cache race for unaligned extents

2026-06-01T15:54:50+00:00

[ Upstream commit 649932fc3815eda2f24eb4de4b3a5e94886ee0b9 ] After unaligned compressed extents were introduced, the following race could occur: [Thread 1] [Thread 2] (z_erofs_fill_bio_vec) ... filemap_add_folio (1) (z_erofs_bind_cache) .. .. folio_attach_private (2) filemap_add_folio (3) again Since (1) is executed but (2) hasn't been executed yet, it's possible that another thread finds the same managed folio in z_erofs_bind_cache() for a different pcluster and calls filemap_add_folio() again since folio->private is still Z_EROFS_PREALLOCATED_FOLIO. Fix this by explicitly clearing folio->private before making the folio visible in the managed cache so that another pcluster can simply wait on the locked managed folio as what we did for other shared cases [1]. This only impacts unaligned data compression (`-E48bit` with zstd, for example). [1] Commit 9e2f9d34dd12 ("erofs: handle overlapped pclusters out of crafted images properly") was originally introduced to handle crafted overlapped extents, but it addresses unaligned extents as well. Fixes: 7361d1e3763b ("erofs: support unaligned encoded data") Reported-by: Arseniy Krasnov Closes: https://lore.kernel.org/r/4a2f3801-fac1-42fe-ae75-da315822e088@salutedevices.com Tested-by: Arseniy Krasnov Signed-off-by: Gao Xiang Signed-off-by: Sasha Levin

erofs: unify lcn as u64 for 32-bit platforms

2026-05-23T11:09:16+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

2026-05-23T11:08:27+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

2026-05-23T11:08:26+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()

2026-05-07T04:14:13+00:00

commit 21e161de2dc660b1bb70ef5b156ab8e6e1cca3ab upstream. 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: Greg Kroah-Hartman

lsm: add backing_file LSM hooks

2026-05-07T04:14:01+00:00

commit 6af36aeb147a06dea47c49859cd6ca5659aeb987 upstream. Stacked filesystems such as overlayfs do not currently provide the necessary mechanisms for LSMs to properly enforce access controls on the mmap() and mprotect() operations. In order to resolve this gap, a LSM security blob is being added to the backing_file struct and the following new LSM hooks are being created: security_backing_file_alloc() security_backing_file_free() security_mmap_backing_file() The first two hooks are to manage the lifecycle of the LSM security blob in the backing_file struct, while the third provides a new mmap() access control point for the underlying backing file. It is also expected that LSMs will likely want to update their security_file_mprotect() callback to address issues with their mprotect() controls, but that does not require a change to the security_file_mprotect() LSM hook. There are a three other small changes to support these new LSM hooks: * Pass the user file associated with a backing file down to alloc_empty_backing_file() so it can be included in the security_backing_file_alloc() hook. * Add getter and setter functions for the backing_file struct LSM blob as the backing_file struct remains private to fs/file_table.c. * Constify the file struct field in the LSM common_audit_data struct to better support LSMs that need to pass a const file struct pointer into the common LSM audit code. Thanks to Arnd Bergmann for identifying the missing EXPORT_SYMBOL_GPL() and supplying a fixup. Cc: stable@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-unionfs@vger.kernel.org Cc: linux-erofs@lists.ozlabs.org Reviewed-by: Amir Goldstein Reviewed-by: Serge Hallyn Reviewed-by: Christian Brauner Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

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

2026-05-07T04:13:49+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: fix .fadvise() for page cache sharing

2026-03-25T02:40:02+00:00

Currently, .fadvise() doesn't work well if page cache sharing is on since shared inodes belong to a pseudo fs generated with init_pseudo(), and sb->s_bdi is the default one &noop_backing_dev_info. Then, generic_fadvise() will just behave as a no-op if sb->s_bdi is &noop_backing_dev_info, but as the bdev fs (the bdev fs changes inode_to_bdi() instead), it's actually NOT a pure memfs. Let's generate a real bdi for erofs_ishare_mnt instead. Fixes: d86d7817c042 ("erofs: implement .fadvise for page cache share") Reviewed-by: Hongbo Li Signed-off-by: Gao Xiang