[Ocfs2-devel] [PATCH v2] ocfs2: Do not write error flag to user structure we cannot copy from/to
Ben Hutchings
ben at decadent.org.uk
Sun Jun 8 15:26:35 PDT 2014
If we failed to copy from the structure, writing back the flags leaks
31 bits of kernel memory (the rest of the ir_flags field).
In any case, if we cannot copy from/to the structure, why should we
expect putting just the flags to work?
Also make sure ocfs2_info_handle_freeinode() returns the right error
code if the copy_to_user() fails.
Compile-tested only.
Signed-off-by: Ben Hutchings <ben at decadent.org.uk>
Fixes: ddee5cdb70e6 ('Ocfs2: Add new OCFS2_IOC_INFO ioctl for ocfs2 v8.')
---
v2: no cc to stable
fs/ocfs2/ioctl.c | 129 +++++++++++++++++++------------------------------------
1 file changed, 43 insertions(+), 86 deletions(-)
diff --git a/fs/ocfs2/ioctl.c b/fs/ocfs2/ioctl.c
index 490229f..2e6bdd4 100644
--- a/fs/ocfs2/ioctl.c
+++ b/fs/ocfs2/ioctl.c
@@ -35,9 +35,8 @@
copy_to_user((typeof(a) __user *)b, &(a), sizeof(a))
/*
- * This call is void because we are already reporting an error that may
- * be -EFAULT. The error will be returned from the ioctl(2) call. It's
- * just a best-effort to tell userspace that this request caused the error.
+ * This is just a best-effort to tell userspace that this request
+ * caused the error.
*/
static inline void o2info_set_request_error(struct ocfs2_info_request *kreq,
struct ocfs2_info_request __user *req)
@@ -146,136 +145,105 @@ bail:
int ocfs2_info_handle_blocksize(struct inode *inode,
struct ocfs2_info_request __user *req)
{
- int status = -EFAULT;
struct ocfs2_info_blocksize oib;
if (o2info_from_user(oib, req))
- goto bail;
+ return -EFAULT;
oib.ib_blocksize = inode->i_sb->s_blocksize;
o2info_set_request_filled(&oib.ib_req);
if (o2info_to_user(oib, req))
- goto bail;
-
- status = 0;
-bail:
- if (status)
- o2info_set_request_error(&oib.ib_req, req);
+ return -EFAULT;
- return status;
+ return 0;
}
int ocfs2_info_handle_clustersize(struct inode *inode,
struct ocfs2_info_request __user *req)
{
- int status = -EFAULT;
struct ocfs2_info_clustersize oic;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
if (o2info_from_user(oic, req))
- goto bail;
+ return -EFAULT;
oic.ic_clustersize = osb->s_clustersize;
o2info_set_request_filled(&oic.ic_req);
if (o2info_to_user(oic, req))
- goto bail;
-
- status = 0;
-bail:
- if (status)
- o2info_set_request_error(&oic.ic_req, req);
+ return -EFAULT;
- return status;
+ return 0;
}
int ocfs2_info_handle_maxslots(struct inode *inode,
struct ocfs2_info_request __user *req)
{
- int status = -EFAULT;
struct ocfs2_info_maxslots oim;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
if (o2info_from_user(oim, req))
- goto bail;
+ return -EFAULT;
oim.im_max_slots = osb->max_slots;
o2info_set_request_filled(&oim.im_req);
if (o2info_to_user(oim, req))
- goto bail;
+ return -EFAULT;
- status = 0;
-bail:
- if (status)
- o2info_set_request_error(&oim.im_req, req);
-
- return status;
+ return 0;
}
int ocfs2_info_handle_label(struct inode *inode,
struct ocfs2_info_request __user *req)
{
- int status = -EFAULT;
struct ocfs2_info_label oil;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
if (o2info_from_user(oil, req))
- goto bail;
+ return -EFAULT;
memcpy(oil.il_label, osb->vol_label, OCFS2_MAX_VOL_LABEL_LEN);
o2info_set_request_filled(&oil.il_req);
if (o2info_to_user(oil, req))
- goto bail;
+ return -EFAULT;
- status = 0;
-bail:
- if (status)
- o2info_set_request_error(&oil.il_req, req);
-
- return status;
+ return 0;
}
int ocfs2_info_handle_uuid(struct inode *inode,
struct ocfs2_info_request __user *req)
{
- int status = -EFAULT;
struct ocfs2_info_uuid oiu;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
if (o2info_from_user(oiu, req))
- goto bail;
+ return -EFAULT;
memcpy(oiu.iu_uuid_str, osb->uuid_str, OCFS2_TEXT_UUID_LEN + 1);
o2info_set_request_filled(&oiu.iu_req);
if (o2info_to_user(oiu, req))
- goto bail;
-
- status = 0;
-bail:
- if (status)
- o2info_set_request_error(&oiu.iu_req, req);
+ return -EFAULT;
- return status;
+ return 0;
}
int ocfs2_info_handle_fs_features(struct inode *inode,
struct ocfs2_info_request __user *req)
{
- int status = -EFAULT;
struct ocfs2_info_fs_features oif;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
if (o2info_from_user(oif, req))
- goto bail;
+ return -EFAULT;
oif.if_compat_features = osb->s_feature_compat;
oif.if_incompat_features = osb->s_feature_incompat;
@@ -284,39 +252,28 @@ int ocfs2_info_handle_fs_features(struct inode *inode,
o2info_set_request_filled(&oif.if_req);
if (o2info_to_user(oif, req))
- goto bail;
+ return -EFAULT;
- status = 0;
-bail:
- if (status)
- o2info_set_request_error(&oif.if_req, req);
-
- return status;
+ return 0;
}
int ocfs2_info_handle_journal_size(struct inode *inode,
struct ocfs2_info_request __user *req)
{
- int status = -EFAULT;
struct ocfs2_info_journal_size oij;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
if (o2info_from_user(oij, req))
- goto bail;
+ return -EFAULT;
oij.ij_journal_size = i_size_read(osb->journal->j_inode);
o2info_set_request_filled(&oij.ij_req);
if (o2info_to_user(oij, req))
- goto bail;
+ return -EFAULT;
- status = 0;
-bail:
- if (status)
- o2info_set_request_error(&oij.ij_req, req);
-
- return status;
+ return 0;
}
int ocfs2_info_scan_inode_alloc(struct ocfs2_super *osb,
@@ -372,7 +329,7 @@ int ocfs2_info_handle_freeinode(struct inode *inode,
u32 i;
u64 blkno = -1;
char namebuf[40];
- int status = -EFAULT, type = INODE_ALLOC_SYSTEM_INODE;
+ int status, type = INODE_ALLOC_SYSTEM_INODE;
struct ocfs2_info_freeinode *oifi = NULL;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
struct inode *inode_alloc = NULL;
@@ -384,8 +341,10 @@ int ocfs2_info_handle_freeinode(struct inode *inode,
goto out_err;
}
- if (o2info_from_user(*oifi, req))
- goto bail;
+ if (o2info_from_user(*oifi, req)) {
+ status = -EFAULT;
+ goto out_free;
+ }
oifi->ifi_slotnum = osb->max_slots;
@@ -423,14 +382,16 @@ int ocfs2_info_handle_freeinode(struct inode *inode,
o2info_set_request_filled(&oifi->ifi_req);
- if (o2info_to_user(*oifi, req))
- goto bail;
+ if (o2info_to_user(*oifi, req)) {
+ status = -EFAULT;
+ goto out_free;
+ }
status = 0;
bail:
if (status)
o2info_set_request_error(&oifi->ifi_req, req);
-
+out_free:
kfree(oifi);
out_err:
return status;
@@ -657,7 +618,7 @@ int ocfs2_info_handle_freefrag(struct inode *inode,
{
u64 blkno = -1;
char namebuf[40];
- int status = -EFAULT, type = GLOBAL_BITMAP_SYSTEM_INODE;
+ int status, type = GLOBAL_BITMAP_SYSTEM_INODE;
struct ocfs2_info_freefrag *oiff;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
@@ -670,8 +631,10 @@ int ocfs2_info_handle_freefrag(struct inode *inode,
goto out_err;
}
- if (o2info_from_user(*oiff, req))
- goto bail;
+ if (o2info_from_user(*oiff, req)) {
+ status = -EFAULT;
+ goto out_free;
+ }
/*
* chunksize from userspace should be power of 2.
*/
@@ -710,14 +673,14 @@ int ocfs2_info_handle_freefrag(struct inode *inode,
if (o2info_to_user(*oiff, req)) {
status = -EFAULT;
- goto bail;
+ goto out_free;
}
status = 0;
bail:
if (status)
o2info_set_request_error(&oiff->iff_req, req);
-
+out_free:
kfree(oiff);
out_err:
return status;
@@ -726,23 +689,17 @@ out_err:
int ocfs2_info_handle_unknown(struct inode *inode,
struct ocfs2_info_request __user *req)
{
- int status = -EFAULT;
struct ocfs2_info_request oir;
if (o2info_from_user(oir, req))
- goto bail;
+ return -EFAULT;
o2info_clear_request_filled(&oir);
if (o2info_to_user(oir, req))
- goto bail;
+ return -EFAULT;
- status = 0;
-bail:
- if (status)
- o2info_set_request_error(&oir, req);
-
- return status;
+ return 0;
}
/*
--
Ben Hutchings
Never attribute to conspiracy what can adequately be explained by stupidity.
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