[Ocfs2-devel] [PATCH 1/5] ocfs2: Check xattr block signatures properly.
Joel Becker
joel.becker at oracle.com
Mon Oct 20 19:08:14 PDT 2008
The xattr.c code is currently memcmp()ing naking buffer pointers.
Create the OCFS2_IS_VALID_XATTR_BLOCK() macro to match its peers and use
that.
In addition, failed signature checks were returning -EFAULT, which is
completely wrong. Return -EIO.
Signed-off-by: Joel Becker <joel.becker at oracle.com>
---
fs/ocfs2/ocfs2.h | 3 +++
fs/ocfs2/xattr.c | 38 ++++++++++++++++----------------------
2 files changed, 19 insertions(+), 22 deletions(-)
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index a21a465..fef7ece 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -473,6 +473,9 @@ static inline int ocfs2_uses_extended_slot_map(struct ocfs2_super *osb)
(____gd)->bg_signature); \
} while (0)
+#define OCFS2_IS_VALID_XATTR_BLOCK(ptr) \
+ (!strcmp((ptr)->xb_signature, OCFS2_XATTR_BLOCK_SIGNATURE))
+
static inline unsigned long ino_from_blkno(struct super_block *sb,
u64 blkno)
{
diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 802c414..44d58f1 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -542,14 +542,12 @@ static int ocfs2_xattr_block_list(struct inode *inode,
mlog_errno(ret);
return ret;
}
- /*Verify the signature of xattr block*/
- if (memcmp((void *)blk_bh->b_data, OCFS2_XATTR_BLOCK_SIGNATURE,
- strlen(OCFS2_XATTR_BLOCK_SIGNATURE))) {
- ret = -EFAULT;
- goto cleanup;
- }
xb = (struct ocfs2_xattr_block *)blk_bh->b_data;
+ if (!OCFS2_IS_VALID_XATTR_BLOCK(xb)) {
+ ret = -EIO;
+ goto cleanup;
+ }
if (!(le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED)) {
struct ocfs2_xattr_header *header = &xb->xb_attrs.xb_header;
@@ -766,15 +764,14 @@ static int ocfs2_xattr_block_get(struct inode *inode,
mlog_errno(ret);
return ret;
}
- /*Verify the signature of xattr block*/
- if (memcmp((void *)blk_bh->b_data, OCFS2_XATTR_BLOCK_SIGNATURE,
- strlen(OCFS2_XATTR_BLOCK_SIGNATURE))) {
- ret = -EFAULT;
+
+ xb = (struct ocfs2_xattr_block *)blk_bh->b_data;
+ if (!OCFS2_IS_VALID_XATTR_BLOCK(xb)) {
+ ret = -EIO;
goto cleanup;
}
xs->xattr_bh = blk_bh;
- xb = (struct ocfs2_xattr_block *)blk_bh->b_data;
if (!(le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED)) {
xs->header = &xb->xb_attrs.xb_header;
@@ -1514,10 +1511,9 @@ static int ocfs2_xattr_free_block(struct inode *inode,
goto out;
}
- /*Verify the signature of xattr block*/
- if (memcmp((void *)blk_bh->b_data, OCFS2_XATTR_BLOCK_SIGNATURE,
- strlen(OCFS2_XATTR_BLOCK_SIGNATURE))) {
- ret = -EFAULT;
+ xb = (struct ocfs2_xattr_block *)blk_bh->b_data;
+ if (!OCFS2_IS_VALID_XATTR_BLOCK(xb)) {
+ ret = -EIO;
goto out;
}
@@ -1527,7 +1523,6 @@ static int ocfs2_xattr_free_block(struct inode *inode,
goto out;
}
- xb = (struct ocfs2_xattr_block *)blk_bh->b_data;
blk = le64_to_cpu(xb->xb_blkno);
bit = le16_to_cpu(xb->xb_suballoc_bit);
bg_blkno = ocfs2_which_suballoc_group(blk, bit);
@@ -1771,15 +1766,14 @@ static int ocfs2_xattr_block_find(struct inode *inode,
mlog_errno(ret);
return ret;
}
- /*Verify the signature of xattr block*/
- if (memcmp((void *)blk_bh->b_data, OCFS2_XATTR_BLOCK_SIGNATURE,
- strlen(OCFS2_XATTR_BLOCK_SIGNATURE))) {
- ret = -EFAULT;
- goto cleanup;
+
+ xb = (struct ocfs2_xattr_block *)blk_bh->b_data;
+ if (!OCFS2_IS_VALID_XATTR_BLOCK(xb)) {
+ ret = -EIO;
+ goto cleanup;
}
xs->xattr_bh = blk_bh;
- xb = (struct ocfs2_xattr_block *)blk_bh->b_data;
if (!(le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED)) {
xs->header = &xb->xb_attrs.xb_header;
--
1.5.6.5
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