kernel/linux.git/fs/ext4/inode.c, branch v6.6.131

ext4: convert inline data to extents when truncate exceeds inline size

2026-04-02T11:07:27+00:00

commit ed9356a30e59c7cc3198e7fc46cfedf3767b9b17 upstream. Add a check in ext4_setattr() to convert files from inline data storage to extent-based storage when truncate() grows the file size beyond the inline capacity. This prevents the filesystem from entering an inconsistent state where the inline data flag is set but the file size exceeds what can be stored inline. Without this fix, the following sequence causes a kernel BUG_ON(): 1. Mount filesystem with inode that has inline flag set and small size 2. truncate(file, 50MB) - grows size but inline flag remains set 3. sendfile() attempts to write data 4. ext4_write_inline_data() hits BUG_ON(write_size > inline_capacity) The crash occurs because ext4_write_inline_data() expects inline storage to accommodate the write, but the actual inline capacity (~60 bytes for i_block + ~96 bytes for xattrs) is far smaller than the file size and write request. The fix checks if the new size from setattr exceeds the inode's actual inline capacity (EXT4_I(inode)->i_inline_size) and converts the file to extent-based storage before proceeding with the size change. This addresses the root cause by ensuring the inline data flag and file size remain consistent during truncate operations. Reported-by: syzbot+7de5fe447862fc37576f@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=7de5fe447862fc37576f Tested-by: syzbot+7de5fe447862fc37576f@syzkaller.appspotmail.com Signed-off-by: Deepanshu Kartikey Link: https://patch.msgid.link/20260207043607.1175976-1-kartikey406@gmail.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

ext4: fix out-of-bound read in ext4_xattr_inode_dec_ref_all()

2026-01-11T14:22:26+00:00

[ Upstream commit 5701875f9609b000d91351eaa6bfd97fe2f157f4 ] There's issue as follows: BUG: KASAN: use-after-free in ext4_xattr_inode_dec_ref_all+0x6ff/0x790 Read of size 4 at addr ffff88807b003000 by task syz-executor.0/15172 CPU: 3 PID: 15172 Comm: syz-executor.0 Call Trace: __dump_stack lib/dump_stack.c:82 [inline] dump_stack+0xbe/0xfd lib/dump_stack.c:123 print_address_description.constprop.0+0x1e/0x280 mm/kasan/report.c:400 __kasan_report.cold+0x6c/0x84 mm/kasan/report.c:560 kasan_report+0x3a/0x50 mm/kasan/report.c:585 ext4_xattr_inode_dec_ref_all+0x6ff/0x790 fs/ext4/xattr.c:1137 ext4_xattr_delete_inode+0x4c7/0xda0 fs/ext4/xattr.c:2896 ext4_evict_inode+0xb3b/0x1670 fs/ext4/inode.c:323 evict+0x39f/0x880 fs/inode.c:622 iput_final fs/inode.c:1746 [inline] iput fs/inode.c:1772 [inline] iput+0x525/0x6c0 fs/inode.c:1758 ext4_orphan_cleanup fs/ext4/super.c:3298 [inline] ext4_fill_super+0x8c57/0xba40 fs/ext4/super.c:5300 mount_bdev+0x355/0x410 fs/super.c:1446 legacy_get_tree+0xfe/0x220 fs/fs_context.c:611 vfs_get_tree+0x8d/0x2f0 fs/super.c:1576 do_new_mount fs/namespace.c:2983 [inline] path_mount+0x119a/0x1ad0 fs/namespace.c:3316 do_mount+0xfc/0x110 fs/namespace.c:3329 __do_sys_mount fs/namespace.c:3540 [inline] __se_sys_mount+0x219/0x2e0 fs/namespace.c:3514 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x67/0xd1 Memory state around the buggy address: ffff88807b002f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88807b002f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88807b003000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88807b003080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88807b003100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff Above issue happens as ext4_xattr_delete_inode() isn't check xattr is valid if xattr is in inode. To solve above issue call xattr_check_inode() check if xattr if valid in inode. In fact, we can directly verify in ext4_iget_extra_inode(), so that there is no divergent verification. Fixes: e50e5129f384 ("ext4: xattr-in-inode support") Signed-off-by: Ye Bin Reviewed-by: Jan Kara Link: https://patch.msgid.link/20250208063141.1539283-3-yebin@huaweicloud.com Signed-off-by: Theodore Ts'o Signed-off-by: David Nyström Signed-off-by: Greg Kroah-Hartman

ext4: clear i_state_flags when alloc inode

2026-01-11T14:21:55+00:00

commit 4091c8206cfd2e3bb529ef260887296b90d9b6a2 upstream. i_state_flags used on 32-bit archs, need to clear this flag when alloc inode. Find this issue when umount ext4, sometimes track the inode as orphan accidently, cause ext4 mesg dump. Fixes: acf943e9768e ("ext4: fix checks for orphan inodes") Signed-off-by: Haibo Chen Reviewed-by: Baokun Li Reviewed-by: Zhang Yi Reviewed-by: Jan Kara Message-ID: <20251104-ext4-v1-1-73691a0800f9@nxp.com> Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

ext4: detect invalid INLINE_DATA + EXTENTS flag combination

2025-10-23T14:16:24+00:00

commit 1d3ad183943b38eec2acf72a0ae98e635dc8456b upstream. syzbot reported a BUG_ON in ext4_es_cache_extent() when opening a verity file on a corrupted ext4 filesystem mounted without a journal. The issue is that the filesystem has an inode with both the INLINE_DATA and EXTENTS flags set: EXT4-fs error (device loop0): ext4_cache_extents:545: inode #15: comm syz.0.17: corrupted extent tree: lblk 0 < prev 66 Investigation revealed that the inode has both flags set: DEBUG: inode 15 - flag=1, i_inline_off=164, has_inline=1, extents_flag=1 This is an invalid combination since an inode should have either: - INLINE_DATA: data stored directly in the inode - EXTENTS: data stored in extent-mapped blocks Having both flags causes ext4_has_inline_data() to return true, skipping extent tree validation in __ext4_iget(). The unvalidated out-of-order extents then trigger a BUG_ON in ext4_es_cache_extent() due to integer underflow when calculating hole sizes. Fix this by detecting this invalid flag combination early in ext4_iget() and rejecting the corrupted inode. Cc: stable@kernel.org Reported-and-tested-by: syzbot+038b7bf43423e132b308@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=038b7bf43423e132b308 Suggested-by: Zhang Yi Signed-off-by: Deepanshu Kartikey Reviewed-by: Zhang Yi Message-ID: <20250930112810.315095-1-kartikey406@gmail.com> Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

ext4: increase i_disksize to offset + len in ext4_update_disksize_before_punch()

2025-10-19T14:30:56+00:00

commit 9d80eaa1a1d37539224982b76c9ceeee736510b9 upstream. After running a stress test combined with fault injection, we performed fsck -a followed by fsck -fn on the filesystem image. During the second pass, fsck -fn reported: Inode 131512, end of extent exceeds allowed value (logical block 405, physical block 1180540, len 2) This inode was not in the orphan list. Analysis revealed the following call chain that leads to the inconsistency: ext4_da_write_end() //does not update i_disksize ext4_punch_hole() //truncate folio, keep size ext4_page_mkwrite() ext4_block_page_mkwrite() ext4_block_write_begin() ext4_get_block() //insert written extent without update i_disksize journal commit echo 1 > /sys/block/xxx/device/delete da-write path updates i_size but does not update i_disksize. Then ext4_punch_hole truncates the da-folio yet still leaves i_disksize unchanged(in the ext4_update_disksize_before_punch function, the condition offset + len < size is met). Then ext4_page_mkwrite sees ext4_nonda_switch return 1 and takes the nodioread_nolock path, the folio about to be written has just been punched out, and it’s offset sits beyond the current i_disksize. This may result in a written extent being inserted, but again does not update i_disksize. If the journal gets committed and then the block device is yanked, we might run into this. It should be noted that replacing ext4_punch_hole with ext4_zero_range in the call sequence may also trigger this issue, as neither will update i_disksize under these circumstances. To fix this, we can modify ext4_update_disksize_before_punch to increase i_disksize to min(i_size, offset + len) when both i_size and (offset + len) are greater than i_disksize. Cc: stable@kernel.org Signed-off-by: Yongjian Sun Reviewed-by: Zhang Yi Reviewed-by: Jan Kara Reviewed-by: Baokun Li Message-ID: <20250911133024.1841027-1-sunyongjian@huaweicloud.com> Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

ext4: fix checks for orphan inodes

2025-10-15T09:58:08+00:00

commit acf943e9768ec9d9be80982ca0ebc4bfd6b7631e upstream. When orphan file feature is enabled, inode can be tracked as orphan either in the standard orphan list or in the orphan file. The first can be tested by checking ei->i_orphan list head, the second is recorded by EXT4_STATE_ORPHAN_FILE inode state flag. There are several places where we want to check whether inode is tracked as orphan and only some of them properly check for both possibilities. Luckily the consequences are mostly minor, the worst that can happen is that we track an inode as orphan although we don't need to and e2fsck then complains (resulting in occasional ext4/307 xfstest failures). Fix the problem by introducing a helper for checking whether an inode is tracked as orphan and use it in appropriate places. Fixes: 4a79a98c7b19 ("ext4: Improve scalability of ext4 orphan file handling") Cc: stable@kernel.org Signed-off-by: Jan Kara Reviewed-by: Zhang Yi Message-ID: <20250925123038.20264-2-jack@suse.cz> Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

ext4: check fast symlink for ea_inode correctly

2025-08-28T14:28:34+00:00

commit b4cc4a4077268522e3d0d34de4b2dc144e2330fa upstream. The check for a fast symlink in the presence of only an external xattr inode is incorrect. If a fast symlink does not have an xattr block (i_file_acl == 0), but does have an external xattr inode that increases inode i_blocks, then the check for a fast symlink will incorrectly fail and __ext4_iget()->ext4_ind_check_inode() will report the inode is corrupt when it "validates" i_data[] on the next read: # ln -s foo /mnt/tmp/bar # setfattr -h -n trusted.test \ -v "$(yes | head -n 4000)" /mnt/tmp/bar # umount /mnt/tmp # mount /mnt/tmp # ls -l /mnt/tmp ls: cannot access '/mnt/tmp/bar': Structure needs cleaning total 4 ? l?????????? ? ? ? ? ? bar # dmesg | tail -1 EXT4-fs error (device dm-8): __ext4_iget:5098: inode #24578: block 7303014: comm ls: invalid block (note that "block 7303014" = 0x6f6f66 = "foo" in LE order). ext4_inode_is_fast_symlink() should check the superblock EXT4_FEATURE_INCOMPAT_EA_INODE feature flag, not the inode EXT4_EA_INODE_FL, since the latter is only set on the xattr inode itself, and not on the inode that uses this xattr. Cc: stable@vger.kernel.org Fixes: fc82228a5e38 ("ext4: support fast symlinks from ext3 file systems") Signed-off-by: Andreas Dilger Reviewed-by: Li Dongyang Reviewed-by: Alex Zhuravlev Reviewed-by: Oleg Drokin Reviewed-on: https://review.whamcloud.com/59879 Lustre-bug-id: https://jira.whamcloud.com/browse/LU-19121 Link: https://patch.msgid.link/20250717063709.757077-1-adilger@dilger.ca Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

ext4: only dirty folios when data journaling regular files

2025-06-27T10:08:47+00:00

commit e26268ff1dcae5662c1b96c35f18cfa6ab73d9de upstream. fstest generic/388 occasionally reproduces a crash that looks as follows: BUG: kernel NULL pointer dereference, address: 0000000000000000 ... Call Trace: ext4_block_zero_page_range+0x30c/0x380 [ext4] ext4_truncate+0x436/0x440 [ext4] ext4_process_orphan+0x5d/0x110 [ext4] ext4_orphan_cleanup+0x124/0x4f0 [ext4] ext4_fill_super+0x262d/0x3110 [ext4] get_tree_bdev_flags+0x132/0x1d0 vfs_get_tree+0x26/0xd0 vfs_cmd_create+0x59/0xe0 __do_sys_fsconfig+0x4ed/0x6b0 do_syscall_64+0x82/0x170 ... This occurs when processing a symlink inode from the orphan list. The partial block zeroing code in the truncate path calls ext4_dirty_journalled_data() -> folio_mark_dirty(). The latter calls mapping->a_ops->dirty_folio(), but symlink inodes are not assigned an a_ops vector in ext4, hence the crash. To avoid this problem, update the ext4_dirty_journalled_data() helper to only mark the folio dirty on regular files (for which a_ops is assigned). This also matches the journaling logic in the ext4_symlink() creation path, where ext4_handle_dirty_metadata() is called directly. Fixes: d84c9ebdac1e ("ext4: Mark pages with journalled data dirty") Signed-off-by: Brian Foster Link: https://patch.msgid.link/20250516173800.175577-1-bfoster@redhat.com Signed-off-by: Theodore Ts'o Reviewed-by: Jan Kara Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

ext4: ensure i_size is smaller than maxbytes

2025-06-27T10:08:47+00:00

commit 1a77a028a392fab66dd637cdfac3f888450d00af upstream. The inode i_size cannot be larger than maxbytes, check it while loading inode from the disk. Signed-off-by: Zhang Yi Reviewed-by: Jan Kara Reviewed-by: Baokun Li Link: https://patch.msgid.link/20250506012009.3896990-4-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

ext4: remove writable userspace mappings before truncating page cache

2025-06-04T12:42:12+00:00

[ Upstream commit 17207d0bb209e8b40f27d7f3f96e82a78af0bf2c ] When zeroing a range of folios on the filesystem which block size is less than the page size, the file's mapped blocks within one page will be marked as unwritten, we should remove writable userspace mappings to ensure that ext4_page_mkwrite() can be called during subsequent write access to these partial folios. Otherwise, data written by subsequent mmap writes may not be saved to disk. $mkfs.ext4 -b 1024 /dev/vdb $mount /dev/vdb /mnt $xfs_io -t -f -c "pwrite -S 0x58 0 4096" -c "mmap -rw 0 4096" \ -c "mwrite -S 0x5a 2048 2048" -c "fzero 2048 2048" \ -c "mwrite -S 0x59 2048 2048" -c "close" /mnt/foo $od -Ax -t x1z /mnt/foo 000000 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 * 000800 59 59 59 59 59 59 59 59 59 59 59 59 59 59 59 59 * 001000 $umount /mnt && mount /dev/vdb /mnt $od -Ax -t x1z /mnt/foo 000000 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58 * 000800 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 001000 Fix this by introducing ext4_truncate_page_cache_block_range() to remove writable userspace mappings when truncating a partial folio range. Additionally, move the journal data mode-specific handlers and truncate_pagecache_range() into this function, allowing it to serve as a common helper that correctly manages the page cache in preparation for block range manipulations. Signed-off-by: Zhang Yi Reviewed-by: Jan Kara Reviewed-by: Ojaswin Mujoo Link: https://patch.msgid.link/20241220011637.1157197-2-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin