Commit 3d777a64 authored by Haogang Chen's avatar Haogang Chen Committed by Linus Torvalds

nilfs2: clamp ns_r_segments_percentage to [1, 99]

ns_r_segments_percentage is read from the disk.  Bogus or malicious
value could cause integer overflow and malfunction due to meaningless
disk usage calculation.  This patch reports error when mounting such
bogus volumes.
Signed-off-by: default avatarHaogang Chen <>
Signed-off-by: default avatarRyusuke Konishi <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent cf2b94da
......@@ -409,6 +409,12 @@ static int nilfs_store_disk_layout(struct the_nilfs *nilfs,
nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block);
nilfs->ns_r_segments_percentage =
if (nilfs->ns_r_segments_percentage < 1 ||
nilfs->ns_r_segments_percentage > 99) {
printk(KERN_ERR "NILFS: invalid reserved segments percentage.\n");
return -EINVAL;
nilfs_set_nsegments(nilfs, le64_to_cpu(sbp->s_nsegments));
nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed);
return 0;
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