[PATCH v2 2/2] f2fs: do more integrity verification for superblock

From: Chao Yu
Date: Mon Dec 14 2015 - 20:59:08 EST


Do more sanity check for superblock during ->mount.

Signed-off-by: Chao Yu <chao2.yu@xxxxxxxxxxx>
---
v2:
o fix incorrect check for main_blkaddr.
fs/f2fs/super.c | 98 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 98 insertions(+)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index dbf16ad..a6f2bed 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -918,6 +918,79 @@ static loff_t max_file_size(unsigned bits)
return result;
}

+static inline bool sanity_check_area_boundary(struct super_block *sb,
+ struct f2fs_super_block *raw_super)
+{
+ u32 segment0_blkaddr = le32_to_cpu(raw_super->segment0_blkaddr);
+ u32 cp_blkaddr = le32_to_cpu(raw_super->cp_blkaddr);
+ u32 sit_blkaddr = le32_to_cpu(raw_super->sit_blkaddr);
+ u32 nat_blkaddr = le32_to_cpu(raw_super->nat_blkaddr);
+ u32 ssa_blkaddr = le32_to_cpu(raw_super->ssa_blkaddr);
+ u32 main_blkaddr = le32_to_cpu(raw_super->main_blkaddr);
+ u32 segment_count_ckpt = le32_to_cpu(raw_super->segment_count_ckpt);
+ u32 segment_count_sit = le32_to_cpu(raw_super->segment_count_sit);
+ u32 segment_count_nat = le32_to_cpu(raw_super->segment_count_nat);
+ u32 segment_count_ssa = le32_to_cpu(raw_super->segment_count_ssa);
+ u32 segment_count_main = le32_to_cpu(raw_super->segment_count_main);
+ u32 segment_count = le32_to_cpu(raw_super->segment_count);
+ u32 log_blocks_per_seg = le32_to_cpu(raw_super->log_blocks_per_seg);
+
+ if (segment0_blkaddr != cp_blkaddr) {
+ f2fs_msg(sb, KERN_INFO,
+ "Mismatch start address, segment0(%u) cp_blkaddr(%u)",
+ segment0_blkaddr, cp_blkaddr);
+ return true;
+ }
+
+ if (cp_blkaddr + (segment_count_ckpt << log_blocks_per_seg) !=
+ sit_blkaddr) {
+ f2fs_msg(sb, KERN_INFO,
+ "Wrong CP boundary, start(%u) end(%u) blocks(%u)",
+ cp_blkaddr, sit_blkaddr,
+ segment_count_ckpt << log_blocks_per_seg);
+ return true;
+ }
+
+ if (sit_blkaddr + (segment_count_sit << log_blocks_per_seg) !=
+ nat_blkaddr) {
+ f2fs_msg(sb, KERN_INFO,
+ "Wrong SIT boundary, start(%u) end(%u) blocks(%u)",
+ sit_blkaddr, nat_blkaddr,
+ segment_count_sit << log_blocks_per_seg);
+ return true;
+ }
+
+ if (nat_blkaddr + (segment_count_nat << log_blocks_per_seg) !=
+ ssa_blkaddr) {
+ f2fs_msg(sb, KERN_INFO,
+ "Wrong NAT boundary, start(%u) end(%u) blocks(%u)",
+ nat_blkaddr, ssa_blkaddr,
+ segment_count_nat << log_blocks_per_seg);
+ return true;
+ }
+
+ if (ssa_blkaddr + (segment_count_ssa << log_blocks_per_seg) !=
+ main_blkaddr) {
+ f2fs_msg(sb, KERN_INFO,
+ "Wrong SSA boundary, start(%u) end(%u) blocks(%u)",
+ ssa_blkaddr, main_blkaddr,
+ segment_count_ssa << log_blocks_per_seg);
+ return true;
+ }
+
+ if (main_blkaddr + (segment_count_main << log_blocks_per_seg) !=
+ segment0_blkaddr + (segment_count << log_blocks_per_seg)) {
+ f2fs_msg(sb, KERN_INFO,
+ "Wrong MAIN_AREA boundary, start(%u) end(%u) blocks(%u)",
+ main_blkaddr,
+ segment0_blkaddr + (segment_count << log_blocks_per_seg),
+ segment_count_main << log_blocks_per_seg);
+ return true;
+ }
+
+ return false;
+}
+
static int sanity_check_raw_super(struct super_block *sb,
struct f2fs_super_block *raw_super)
{
@@ -947,6 +1020,14 @@ static int sanity_check_raw_super(struct super_block *sb,
return 1;
}

+ /* check log blocks per segment */
+ if (le32_to_cpu(raw_super->log_blocks_per_seg) != 9) {
+ f2fs_msg(sb, KERN_INFO,
+ "Invalid log blocks per segment (%u)\n",
+ le32_to_cpu(raw_super->log_blocks_per_seg));
+ return 1;
+ }
+
/* Currently, support 512/1024/2048/4096 bytes sector size */
if (le32_to_cpu(raw_super->log_sectorsize) >
F2FS_MAX_LOG_SECTOR_SIZE ||
@@ -965,6 +1046,23 @@ static int sanity_check_raw_super(struct super_block *sb,
le32_to_cpu(raw_super->log_sectorsize));
return 1;
}
+
+ /* check reserved ino info */
+ if (le32_to_cpu(raw_super->node_ino) != 1 ||
+ le32_to_cpu(raw_super->meta_ino) != 2 ||
+ le32_to_cpu(raw_super->root_ino) != 3) {
+ f2fs_msg(sb, KERN_INFO,
+ "Invalid Fs Meta Ino: node(%u) meta(%u) root(%u)",
+ le32_to_cpu(raw_super->node_ino),
+ le32_to_cpu(raw_super->meta_ino),
+ le32_to_cpu(raw_super->root_ino));
+ return 1;
+ }
+
+ /* check CP/SIT/NAT/SSA/MAIN_AREA area boundary */
+ if (sanity_check_area_boundary(sb, raw_super))
+ return 1;
+
return 0;
}

--
2.6.3


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/