* [PATCH 1/3 v2] fs: ocfs2: Fix possible null-pointer dereferences in ocfs2_xa_prepare_entry()
@ 2019-07-26 10:14 Jia-Ju Bai
2019-07-27 0:49 ` Joseph Qi
2019-09-03 16:03 ` [1/3 v2] " Markus Elfring
0 siblings, 2 replies; 4+ messages in thread
From: Jia-Ju Bai @ 2019-07-26 10:14 UTC (permalink / raw)
To: mark, jlbec, joseph.qi; +Cc: ocfs2-devel, linux-kernel, Jia-Ju Bai
In ocfs2_xa_prepare_entry(), there is an if statement on line 2136 to
check whether loc->xl_entry is NULL:
if (loc->xl_entry)
When loc->xl_entry is NULL, it is used on line 2158:
ocfs2_xa_add_entry(loc, name_hash);
loc->xl_entry->xe_name_hash = cpu_to_le32(name_hash);
loc->xl_entry->xe_name_offset = cpu_to_le16(loc->xl_size);
and line 2164:
ocfs2_xa_add_namevalue(loc, xi);
loc->xl_entry->xe_value_size = cpu_to_le64(xi->xi_value_len);
loc->xl_entry->xe_name_len = xi->xi_name_len;
Thus, possible null-pointer dereferences may occur.
To fix these bugs, if loc-xl_entry is NULL, ocfs2_xa_prepare_entry()
abnormally returns with -EINVAL.
These bugs are found by a static analysis tool STCheck written by us.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
v2:
* Directly return -EINVAL if loc-xl_entry is NULL.
Thank Joseph for helpful advice.
---
fs/ocfs2/xattr.c | 44 +++++++++++++++++++++++---------------------
1 file changed, 23 insertions(+), 21 deletions(-)
diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 385f3aaa2448..4b876c82a35c 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -2133,29 +2133,31 @@ static int ocfs2_xa_prepare_entry(struct ocfs2_xa_loc *loc,
if (rc)
goto out;
- if (loc->xl_entry) {
- if (ocfs2_xa_can_reuse_entry(loc, xi)) {
- orig_value_size = loc->xl_entry->xe_value_size;
- rc = ocfs2_xa_reuse_entry(loc, xi, ctxt);
- if (rc)
- goto out;
- goto alloc_value;
- }
+ if (!loc->xl_entry) {
+ rc = -EINVAL;
+ goto out;
+ }
- if (!ocfs2_xattr_is_local(loc->xl_entry)) {
- orig_clusters = ocfs2_xa_value_clusters(loc);
- rc = ocfs2_xa_value_truncate(loc, 0, ctxt);
- if (rc) {
- mlog_errno(rc);
- ocfs2_xa_cleanup_value_truncate(loc,
- "overwriting",
- orig_clusters);
- goto out;
- }
+ if (ocfs2_xa_can_reuse_entry(loc, xi)) {
+ orig_value_size = loc->xl_entry->xe_value_size;
+ rc = ocfs2_xa_reuse_entry(loc, xi, ctxt);
+ if (rc)
+ goto out;
+ goto alloc_value;
+ }
+
+ if (!ocfs2_xattr_is_local(loc->xl_entry)) {
+ orig_clusters = ocfs2_xa_value_clusters(loc);
+ rc = ocfs2_xa_value_truncate(loc, 0, ctxt);
+ if (rc) {
+ mlog_errno(rc);
+ ocfs2_xa_cleanup_value_truncate(loc,
+ "overwriting",
+ orig_clusters);
+ goto out;
}
- ocfs2_xa_wipe_namevalue(loc);
- } else
- ocfs2_xa_add_entry(loc, name_hash);
+ }
+ ocfs2_xa_wipe_namevalue(loc);
/*
* If we get here, we have a blank entry. Fill it. We grow our
--
2.17.0
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH 1/3 v2] fs: ocfs2: Fix possible null-pointer dereferences in ocfs2_xa_prepare_entry()
2019-07-26 10:14 [PATCH 1/3 v2] fs: ocfs2: Fix possible null-pointer dereferences in ocfs2_xa_prepare_entry() Jia-Ju Bai
@ 2019-07-27 0:49 ` Joseph Qi
2019-08-05 3:08 ` [Ocfs2-devel] " Changwei Ge
2019-09-03 16:03 ` [1/3 v2] " Markus Elfring
1 sibling, 1 reply; 4+ messages in thread
From: Joseph Qi @ 2019-07-27 0:49 UTC (permalink / raw)
To: Jia-Ju Bai, mark, jlbec, Andrew Morton; +Cc: ocfs2-devel, linux-kernel
On 19/7/26 18:14, Jia-Ju Bai wrote:
> In ocfs2_xa_prepare_entry(), there is an if statement on line 2136 to
> check whether loc->xl_entry is NULL:
> if (loc->xl_entry)
>
> When loc->xl_entry is NULL, it is used on line 2158:
> ocfs2_xa_add_entry(loc, name_hash);
> loc->xl_entry->xe_name_hash = cpu_to_le32(name_hash);
> loc->xl_entry->xe_name_offset = cpu_to_le16(loc->xl_size);
> and line 2164:
> ocfs2_xa_add_namevalue(loc, xi);
> loc->xl_entry->xe_value_size = cpu_to_le64(xi->xi_value_len);
> loc->xl_entry->xe_name_len = xi->xi_name_len;
>
> Thus, possible null-pointer dereferences may occur.
>
> To fix these bugs, if loc-xl_entry is NULL, ocfs2_xa_prepare_entry()
> abnormally returns with -EINVAL.
>
> These bugs are found by a static analysis tool STCheck written by us.
>
> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
> ---
> v2:
> * Directly return -EINVAL if loc-xl_entry is NULL.
> Thank Joseph for helpful advice.
>
> ---
> fs/ocfs2/xattr.c | 44 +++++++++++++++++++++++---------------------
> 1 file changed, 23 insertions(+), 21 deletions(-)
>
> diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
> index 385f3aaa2448..4b876c82a35c 100644
> --- a/fs/ocfs2/xattr.c
> +++ b/fs/ocfs2/xattr.c
> @@ -2133,29 +2133,31 @@ static int ocfs2_xa_prepare_entry(struct ocfs2_xa_loc *loc,
> if (rc)
> goto out;
>
> - if (loc->xl_entry) {
> - if (ocfs2_xa_can_reuse_entry(loc, xi)) {
> - orig_value_size = loc->xl_entry->xe_value_size;
> - rc = ocfs2_xa_reuse_entry(loc, xi, ctxt);
> - if (rc)
> - goto out;
> - goto alloc_value;
> - }
> + if (!loc->xl_entry) {
> + rc = -EINVAL;
> + goto out;
> + }
>
> - if (!ocfs2_xattr_is_local(loc->xl_entry)) {
> - orig_clusters = ocfs2_xa_value_clusters(loc);
> - rc = ocfs2_xa_value_truncate(loc, 0, ctxt);
> - if (rc) {
> - mlog_errno(rc);
> - ocfs2_xa_cleanup_value_truncate(loc,
> - "overwriting",
> - orig_clusters);
> - goto out;
> - }
> + if (ocfs2_xa_can_reuse_entry(loc, xi)) {
> + orig_value_size = loc->xl_entry->xe_value_size;
> + rc = ocfs2_xa_reuse_entry(loc, xi, ctxt);
> + if (rc)
> + goto out;
> + goto alloc_value;
> + }
> +
> + if (!ocfs2_xattr_is_local(loc->xl_entry)) {
> + orig_clusters = ocfs2_xa_value_clusters(loc);
> + rc = ocfs2_xa_value_truncate(loc, 0, ctxt);
> + if (rc) {
> + mlog_errno(rc);
> + ocfs2_xa_cleanup_value_truncate(loc,
> + "overwriting",
> + orig_clusters);
> + goto out;
> }
> - ocfs2_xa_wipe_namevalue(loc);
> - } else
> - ocfs2_xa_add_entry(loc, name_hash);
> + }
> + ocfs2_xa_wipe_namevalue(loc);
>
> /*
> * If we get here, we have a blank entry. Fill it. We grow our
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [Ocfs2-devel] [PATCH 1/3 v2] fs: ocfs2: Fix possible null-pointer dereferences in ocfs2_xa_prepare_entry()
2019-07-27 0:49 ` Joseph Qi
@ 2019-08-05 3:08 ` Changwei Ge
0 siblings, 0 replies; 4+ messages in thread
From: Changwei Ge @ 2019-08-05 3:08 UTC (permalink / raw)
To: Joseph Qi, Jia-Ju Bai, mark, jlbec, Andrew Morton
Cc: linux-kernel, ocfs2-devel, Andrew Morton
Hi Jia-Ju,
Please checkout my comments inline.
On 2019/7/27 8:49 上午, Joseph Qi wrote:
>
> On 19/7/26 18:14, Jia-Ju Bai wrote:
>> In ocfs2_xa_prepare_entry(), there is an if statement on line 2136 to
>> check whether loc->xl_entry is NULL:
>> if (loc->xl_entry)
>>
>> When loc->xl_entry is NULL, it is used on line 2158:
>> ocfs2_xa_add_entry(loc, name_hash);
This won't deference a NULL ->xl_entry because ->xlo_add_entry() is
already called to whether ocfs2_xa_block_add_entry() or
ocfs2_xa_bucket_add_entry()
From the function name we can tell the intention it wants to add entry
so of course it should be NULL before calling it.
Thanks,
Changwei
>> loc->xl_entry->xe_name_hash = cpu_to_le32(name_hash);
>> loc->xl_entry->xe_name_offset = cpu_to_le16(loc->xl_size);
>> and line 2164:
>> ocfs2_xa_add_namevalue(loc, xi);
>> loc->xl_entry->xe_value_size = cpu_to_le64(xi->xi_value_len);
>> loc->xl_entry->xe_name_len = xi->xi_name_len;
>>
>> Thus, possible null-pointer dereferences may occur.
>>
>> To fix these bugs, if loc-xl_entry is NULL, ocfs2_xa_prepare_entry()
>> abnormally returns with -EINVAL.
>>
>> These bugs are found by a static analysis tool STCheck written by us.
>>
>> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
>> ---
>> v2:
>> * Directly return -EINVAL if loc-xl_entry is NULL.
>> Thank Joseph for helpful advice.
>>
>> ---
>> fs/ocfs2/xattr.c | 44 +++++++++++++++++++++++---------------------
>> 1 file changed, 23 insertions(+), 21 deletions(-)
>>
>> diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
>> index 385f3aaa2448..4b876c82a35c 100644
>> --- a/fs/ocfs2/xattr.c
>> +++ b/fs/ocfs2/xattr.c
>> @@ -2133,29 +2133,31 @@ static int ocfs2_xa_prepare_entry(struct ocfs2_xa_loc *loc,
>> if (rc)
>> goto out;
>>
>> - if (loc->xl_entry) {
>> - if (ocfs2_xa_can_reuse_entry(loc, xi)) {
>> - orig_value_size = loc->xl_entry->xe_value_size;
>> - rc = ocfs2_xa_reuse_entry(loc, xi, ctxt);
>> - if (rc)
>> - goto out;
>> - goto alloc_value;
>> - }
>> + if (!loc->xl_entry) {
>> + rc = -EINVAL;
>> + goto out;
>> + }
>>
>> - if (!ocfs2_xattr_is_local(loc->xl_entry)) {
>> - orig_clusters = ocfs2_xa_value_clusters(loc);
>> - rc = ocfs2_xa_value_truncate(loc, 0, ctxt);
>> - if (rc) {
>> - mlog_errno(rc);
>> - ocfs2_xa_cleanup_value_truncate(loc,
>> - "overwriting",
>> - orig_clusters);
>> - goto out;
>> - }
>> + if (ocfs2_xa_can_reuse_entry(loc, xi)) {
>> + orig_value_size = loc->xl_entry->xe_value_size;
>> + rc = ocfs2_xa_reuse_entry(loc, xi, ctxt);
>> + if (rc)
>> + goto out;
>> + goto alloc_value;
>> + }
>> +
>> + if (!ocfs2_xattr_is_local(loc->xl_entry)) {
>> + orig_clusters = ocfs2_xa_value_clusters(loc);
>> + rc = ocfs2_xa_value_truncate(loc, 0, ctxt);
>> + if (rc) {
>> + mlog_errno(rc);
>> + ocfs2_xa_cleanup_value_truncate(loc,
>> + "overwriting",
>> + orig_clusters);
>> + goto out;
>> }
>> - ocfs2_xa_wipe_namevalue(loc);
>> - } else
>> - ocfs2_xa_add_entry(loc, name_hash);
>> + }
>> + ocfs2_xa_wipe_namevalue(loc);
>>
>> /*
>> * If we get here, we have a blank entry. Fill it. We grow our
>>
> _______________________________________________
> Ocfs2-devel mailing list
> Ocfs2-devel@oss.oracle.com
> https://oss.oracle.com/mailman/listinfo/ocfs2-devel
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [1/3 v2] ocfs2: Fix possible null-pointer dereferences in ocfs2_xa_prepare_entry()
2019-07-26 10:14 [PATCH 1/3 v2] fs: ocfs2: Fix possible null-pointer dereferences in ocfs2_xa_prepare_entry() Jia-Ju Bai
2019-07-27 0:49 ` Joseph Qi
@ 2019-09-03 16:03 ` Markus Elfring
1 sibling, 0 replies; 4+ messages in thread
From: Markus Elfring @ 2019-09-03 16:03 UTC (permalink / raw)
To: Jia-Ju Bai, ocfs2-devel
Cc: Joel Becker, Joseph Qi, linux-kernel, Mark Fasheh, Andrew Morton,
Stephen Rothwell
> These bugs are found by a static analysis tool STCheck written by us.
Would you like to improve any more commit descriptions also by
adjusting such a wording?
Regards,
Markus
^ permalink raw reply [flat|nested] 4+ messages in thread
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2019-07-26 10:14 [PATCH 1/3 v2] fs: ocfs2: Fix possible null-pointer dereferences in ocfs2_xa_prepare_entry() Jia-Ju Bai
2019-07-27 0:49 ` Joseph Qi
2019-08-05 3:08 ` [Ocfs2-devel] " Changwei Ge
2019-09-03 16:03 ` [1/3 v2] " Markus Elfring
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