From 29115b8c9172d34e67ab26cc4f6c209b7a236d7a Mon Sep 17 00:00:00 2001 From: Wenjie Qi Date: Thu, 21 May 2026 11:16:18 +0800 Subject: f2fs: validate compress cache inode only when enabled commit 5073c66a96a9c23c0c2533ed4ed06e42f9021208 upstream. F2FS_COMPRESS_INO() uses NM_I(sbi)->max_nid as the synthetic inode number for the compressed page cache inode. That inode only exists when the compress_cache mount option is enabled. When compress_cache is disabled, max_nid is outside the valid inode range. A corrupted directory entry that points to ino == max_nid should therefore be rejected by f2fs_check_nid_range(). However, is_meta_ino() currently treats F2FS_COMPRESS_INO() as a meta inode unconditionally, so f2fs_iget() bypasses do_read_inode() and its nid range check, and instantiates a fake internal inode instead. Gate the compressed cache inode case on COMPRESS_CACHE, matching f2fs_init_compress_inode(). With compress_cache disabled, ino == max_nid now follows the normal inode path and is rejected as an out-of-range nid. Cc: stable@kernel.org Fixes: 6ce19aff0b8c ("f2fs: compress: add compress_inode to cache compressed blocks") Signed-off-by: Wenjie Qi Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman --- fs/f2fs/inode.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c index 96d4f15cf791..b79651c5bd04 100644 --- a/fs/f2fs/inode.c +++ b/fs/f2fs/inode.c @@ -476,8 +476,13 @@ static int do_read_inode(struct inode *inode) static bool is_meta_ino(struct f2fs_sb_info *sbi, unsigned int ino) { - return ino == F2FS_NODE_INO(sbi) || ino == F2FS_META_INO(sbi) || - ino == F2FS_COMPRESS_INO(sbi); + if (ino == F2FS_NODE_INO(sbi) || ino == F2FS_META_INO(sbi)) + return true; +#ifdef CONFIG_F2FS_FS_COMPRESSION + if (test_opt(sbi, COMPRESS_CACHE) && ino == F2FS_COMPRESS_INO(sbi)) + return true; +#endif + return false; } struct inode *f2fs_iget(struct super_block *sb, unsigned long ino) -- cgit v1.2.3