From: Pankaj Raghav Date: Mon, 30 Jun 2025 10:40:18 +0000 (+0200) Subject: fs/libfs: don't assume blocksize <= PAGE_SIZE in generic_check_addressable X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=25050181b61aa0153f3a378a5472d134f8e4ef25;p=thirdparty%2Flinux.git fs/libfs: don't assume blocksize <= PAGE_SIZE in generic_check_addressable Since [1], it is possible for filesystems to have blocksize > PAGE_SIZE of the system. Remove the assumption and make the check generic for all blocksizes in generic_check_addressable(). [1] https://lore.kernel.org/linux-xfs/20240822135018.1931258-1-kernel@pankajraghav.com/ Reviewed-by: Jan Kara Signed-off-by: Pankaj Raghav Link: https://lore.kernel.org/20250630104018.213985-1-p.raghav@samsung.com Reviewed-by: Zhang Yi Reviewed-by: Baokun Li Signed-off-by: Christian Brauner --- diff --git a/fs/libfs.c b/fs/libfs.c index 4d1862f589e87..f99ecc3006471 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -1584,13 +1584,17 @@ EXPORT_SYMBOL(generic_file_fsync); int generic_check_addressable(unsigned blocksize_bits, u64 num_blocks) { u64 last_fs_block = num_blocks - 1; - u64 last_fs_page = - last_fs_block >> (PAGE_SHIFT - blocksize_bits); + u64 last_fs_page, max_bytes; + + if (check_shl_overflow(num_blocks, blocksize_bits, &max_bytes)) + return -EFBIG; + + last_fs_page = (max_bytes >> PAGE_SHIFT) - 1; if (unlikely(num_blocks == 0)) return 0; - if ((blocksize_bits < 9) || (blocksize_bits > PAGE_SHIFT)) + if (blocksize_bits < 9) return -EINVAL; if ((last_fs_block > (sector_t)(~0ULL) >> (blocksize_bits - 9)) ||