ns_r_segments_percentage is read from the disk. Bogus or malicious
value could cause integer overflow and potential security holes.
This patch reports error when mounting such bogus volumes.
Signed-off-by: Haogang Chen <haogangchen@xxxxxxxxx>
---
fs/nilfs2/the_nilfs.c | 6 ++++++
1 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index d327140..e12b47b 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -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 =
le32_to_cpu(sbp->s_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;
--
1.7.5.4
--
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