[PATCH] fsck.f2fs: check and fix i_namelen to avoid double free

[PATCH] fsck.f2fs: check and fix i_namelen to avoid double free

[Yunlong Song]

Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
---
 fsck/fsck.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/fsck/fsck.c b/fsck/fsck.c
index 2212aa3..8ff4e4b 100644
--- a/fsck/fsck.c
+++ b/fsck/fsck.c
@@ -643,7 +643,7 @@ void fsck_chk_inode_blk(struct f2fs_sb_info *sbi, u32 nid,
 	u64 i_blocks = le64_to_cpu(node_blk->i.i_blocks);
 	int ofs = get_extra_isize(node_blk);
 	unsigned char *en;
-	int namelen;
+	int namelen, i_namelen;
 	unsigned int idx = 0;
 	int need_fix = 0;
 	int ret;
@@ -850,8 +850,21 @@ skip_blkcnt_fix:
 	en = malloc(F2FS_NAME_LEN + 1);
 	ASSERT(en);
 
-	namelen = convert_encrypted_name(node_blk->i.i_name,
-					le32_to_cpu(node_blk->i.i_namelen),
+	i_namelen = le32_to_cpu(node_blk->i.i_namelen);
+	namelen = strlen((const char *)node_blk->i.i_name);
+	if (i_namelen > F2FS_NAME_LEN) {
+		ASSERT_MSG("ino: 0x%x has i_namelen: 0x%x, "
+				"but has %d characters for name",
+				nid, i_namelen, namelen);
+		if (c.fix_on) {
+			FIX_MSG("[0x%x] i_namelen=0x%x -> 0x%x", nid, i_namelen,
+				namelen);
+			node_blk->i.i_namelen = cpu_to_le32(namelen);
+			need_fix = 1;
+		}
+		i_namelen = namelen;
+	}
+	namelen = convert_encrypted_name(node_blk->i.i_name, i_namelen,
 					en, file_enc_name(&node_blk->i));
 	en[namelen] = '\0';
 	if (ftype == F2FS_FT_ORPHAN)
-- 
1.8.5.2


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Re: [PATCH] fsck.f2fs: check and fix i_namelen to avoid double free

[Sheng Yong]

On 2017/12/15 14:25, Yunlong Song wrote:
> Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
> ---
>   fsck/fsck.c | 19 ++++++++++++++++---
>   1 file changed, 16 insertions(+), 3 deletions(-)
> 
> diff --git a/fsck/fsck.c b/fsck/fsck.c
> index 2212aa3..8ff4e4b 100644
> --- a/fsck/fsck.c
> +++ b/fsck/fsck.c
> @@ -643,7 +643,7 @@ void fsck_chk_inode_blk(struct f2fs_sb_info *sbi, u32 nid,
>   	u64 i_blocks = le64_to_cpu(node_blk->i.i_blocks);
>   	int ofs = get_extra_isize(node_blk);
>   	unsigned char *en;
> -	int namelen;
> +	int namelen, i_namelen;
>   	unsigned int idx = 0;
>   	int need_fix = 0;
>   	int ret;
> @@ -850,8 +850,21 @@ skip_blkcnt_fix:
>   	en = malloc(F2FS_NAME_LEN + 1);
>   	ASSERT(en);
>   
> -	namelen = convert_encrypted_name(node_blk->i.i_name,
> -					le32_to_cpu(node_blk->i.i_namelen),
> +	i_namelen = le32_to_cpu(node_blk->i.i_namelen);
> +	namelen = strlen((const char *)node_blk->i.i_name);
Hi, Yunlong
The strlen doesn't work for encrypted i_name. strlen may get a wrong namelen.

thanks,
Sheng
> +	if (i_namelen > F2FS_NAME_LEN) {
> +		ASSERT_MSG("ino: 0x%x has i_namelen: 0x%x, "
> +				"but has %d characters for name",
> +				nid, i_namelen, namelen);
> +		if (c.fix_on) {
> +			FIX_MSG("[0x%x] i_namelen=0x%x -> 0x%x", nid, i_namelen,
> +				namelen);
> +			node_blk->i.i_namelen = cpu_to_le32(namelen);
> +			need_fix = 1;
> +		}
> +		i_namelen = namelen;
> +	}
> +	namelen = convert_encrypted_name(node_blk->i.i_name, i_namelen,
>   					en, file_enc_name(&node_blk->i));
>   	en[namelen] = '\0';
>   	if (ftype == F2FS_FT_ORPHAN)
> 

[PATCH v2] fsck.f2fs: check and fix i_namelen to avoid double free

[Yunlong Song]

Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
---
 fsck/fsck.c | 23 ++++++++++++++++++-----
 fsck/fsck.h |  3 ++-
 2 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/fsck/fsck.c b/fsck/fsck.c
index 2212aa3..f25799c 100644
--- a/fsck/fsck.c
+++ b/fsck/fsck.c
@@ -539,7 +539,7 @@ int fsck_chk_node_blk(struct f2fs_sb_info *sbi, struct f2fs_inode *inode,
 
 		if (sanity_check_inode(sbi, node_blk))
 			goto err;
-		fsck_chk_inode_blk(sbi, nid, ftype, node_blk, blk_cnt, &ni);
+		fsck_chk_inode_blk(sbi, nid, ftype, node_blk, blk_cnt, &ni, child);
 		quota_add_inode_usage(fsck->qctx, nid, &node_blk->i);
 	} else {
 		switch (ntype) {
@@ -633,7 +633,7 @@ unmatched:
 /* start with valid nid and blkaddr */
 void fsck_chk_inode_blk(struct f2fs_sb_info *sbi, u32 nid,
 		enum FILE_TYPE ftype, struct f2fs_node *node_blk,
-		u32 *blk_cnt, struct node_info *ni)
+		u32 *blk_cnt, struct node_info *ni, struct child_info *child_d)
 {
 	struct f2fs_fsck *fsck = F2FS_FSCK(sbi);
 	struct child_info child;
@@ -850,8 +850,20 @@ skip_blkcnt_fix:
 	en = malloc(F2FS_NAME_LEN + 1);
 	ASSERT(en);
 
-	namelen = convert_encrypted_name(node_blk->i.i_name,
-					le32_to_cpu(node_blk->i.i_namelen),
+	namelen = le32_to_cpu(node_blk->i.i_namelen);
+	if (namelen > F2FS_NAME_LEN) {
+		ASSERT_MSG("ino: 0x%x has i_namelen: 0x%x, "
+				"but has %d characters for name",
+				nid, namelen, child_d->i_namelen);
+		if (c.fix_on) {
+			FIX_MSG("[0x%x] i_namelen=0x%x -> 0x%x", nid, namelen,
+				child_d->i_namelen);
+			node_blk->i.i_namelen = cpu_to_le32(child_d->i_namelen);
+			need_fix = 1;
+		}
+		namelen = child_d->i_namelen;
+	}
+	namelen = convert_encrypted_name(node_blk->i.i_name, namelen,
 					en, file_enc_name(&node_blk->i));
 	en[namelen] = '\0';
 	if (ftype == F2FS_FT_ORPHAN)
@@ -1414,9 +1426,10 @@ static int __chk_dentries(struct f2fs_sb_info *sbi, struct child_info *child,
 				dentry, max, i, last_blk, enc_name);
 
 		blk_cnt = 1;
+		child->i_namelen = name_len;
 		ret = fsck_chk_node_blk(sbi,
 				NULL, le32_to_cpu(dentry[i].ino),
-				ftype, TYPE_INODE, &blk_cnt, NULL);
+				ftype, TYPE_INODE, &blk_cnt, child);
 
 		if (ret && c.fix_on) {
 			int j;
diff --git a/fsck/fsck.h b/fsck/fsck.h
index 0343fbd..d635c5a 100644
--- a/fsck/fsck.h
+++ b/fsck/fsck.h
@@ -54,6 +54,7 @@ struct child_info {
 	u32 pp_ino;		/*parent parent ino*/
 	struct extent_info ei;
 	u32 last_blk;
+	u32 i_namelen;  /* dentry namelen */
 };
 
 struct f2fs_fsck {
@@ -128,7 +129,7 @@ extern int fsck_chk_node_blk(struct f2fs_sb_info *, struct f2fs_inode *, u32,
 		enum FILE_TYPE, enum NODE_TYPE, u32 *,
 		struct child_info *);
 extern void fsck_chk_inode_blk(struct f2fs_sb_info *, u32, enum FILE_TYPE,
-		struct f2fs_node *, u32 *, struct node_info *);
+		struct f2fs_node *, u32 *, struct node_info *, struct child_info *);
 extern int fsck_chk_dnode_blk(struct f2fs_sb_info *, struct f2fs_inode *,
 		u32, enum FILE_TYPE, struct f2fs_node *, u32 *,
 		struct child_info *, struct node_info *);
-- 
1.8.5.2

[PATCH v3] fsck.f2fs: check and fix i_namelen to avoid double free

[Yunlong Song]

Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
---
 fsck/fsck.c | 26 +++++++++++++++++++++-----
 fsck/fsck.h |  3 ++-
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/fsck/fsck.c b/fsck/fsck.c
index 2212aa3..b52b6e4 100644
--- a/fsck/fsck.c
+++ b/fsck/fsck.c
@@ -539,7 +539,7 @@ int fsck_chk_node_blk(struct f2fs_sb_info *sbi, struct f2fs_inode *inode,
 
 		if (sanity_check_inode(sbi, node_blk))
 			goto err;
-		fsck_chk_inode_blk(sbi, nid, ftype, node_blk, blk_cnt, &ni);
+		fsck_chk_inode_blk(sbi, nid, ftype, node_blk, blk_cnt, &ni, child);
 		quota_add_inode_usage(fsck->qctx, nid, &node_blk->i);
 	} else {
 		switch (ntype) {
@@ -633,7 +633,7 @@ unmatched:
 /* start with valid nid and blkaddr */
 void fsck_chk_inode_blk(struct f2fs_sb_info *sbi, u32 nid,
 		enum FILE_TYPE ftype, struct f2fs_node *node_blk,
-		u32 *blk_cnt, struct node_info *ni)
+		u32 *blk_cnt, struct node_info *ni, struct child_info *child_d)
 {
 	struct f2fs_fsck *fsck = F2FS_FSCK(sbi);
 	struct child_info child;
@@ -850,8 +850,23 @@ skip_blkcnt_fix:
 	en = malloc(F2FS_NAME_LEN + 1);
 	ASSERT(en);
 
-	namelen = convert_encrypted_name(node_blk->i.i_name,
-					le32_to_cpu(node_blk->i.i_namelen),
+	namelen = le32_to_cpu(node_blk->i.i_namelen);
+	if (namelen > F2FS_NAME_LEN) {
+		if (child_d && child_d->i_namelen <= F2FS_NAME_LEN) {
+			ASSERT_MSG("ino: 0x%x has i_namelen: 0x%x, "
+					"but has %d characters for name",
+					nid, namelen, child_d->i_namelen);
+			if (c.fix_on) {
+				FIX_MSG("[0x%x] i_namelen=0x%x -> 0x%x", nid, namelen,
+					child_d->i_namelen);
+				node_blk->i.i_namelen = cpu_to_le32(child_d->i_namelen);
+				need_fix = 1;
+			}
+			namelen = child_d->i_namelen;
+		} else
+			namelen = F2FS_NAME_LEN;
+	}
+	namelen = convert_encrypted_name(node_blk->i.i_name, namelen,
 					en, file_enc_name(&node_blk->i));
 	en[namelen] = '\0';
 	if (ftype == F2FS_FT_ORPHAN)
@@ -1414,9 +1429,10 @@ static int __chk_dentries(struct f2fs_sb_info *sbi, struct child_info *child,
 				dentry, max, i, last_blk, enc_name);
 
 		blk_cnt = 1;
+		child->i_namelen = name_len;
 		ret = fsck_chk_node_blk(sbi,
 				NULL, le32_to_cpu(dentry[i].ino),
-				ftype, TYPE_INODE, &blk_cnt, NULL);
+				ftype, TYPE_INODE, &blk_cnt, child);
 
 		if (ret && c.fix_on) {
 			int j;
diff --git a/fsck/fsck.h b/fsck/fsck.h
index 0343fbd..d635c5a 100644
--- a/fsck/fsck.h
+++ b/fsck/fsck.h
@@ -54,6 +54,7 @@ struct child_info {
 	u32 pp_ino;		/*parent parent ino*/
 	struct extent_info ei;
 	u32 last_blk;
+	u32 i_namelen;  /* dentry namelen */
 };
 
 struct f2fs_fsck {
@@ -128,7 +129,7 @@ extern int fsck_chk_node_blk(struct f2fs_sb_info *, struct f2fs_inode *, u32,
 		enum FILE_TYPE, enum NODE_TYPE, u32 *,
 		struct child_info *);
 extern void fsck_chk_inode_blk(struct f2fs_sb_info *, u32, enum FILE_TYPE,
-		struct f2fs_node *, u32 *, struct node_info *);
+		struct f2fs_node *, u32 *, struct node_info *, struct child_info *);
 extern int fsck_chk_dnode_blk(struct f2fs_sb_info *, struct f2fs_inode *,
 		u32, enum FILE_TYPE, struct f2fs_node *, u32 *,
 		struct child_info *, struct node_info *);
-- 
1.8.5.2

[PATCH v4] fsck.f2fs: check and fix i_namelen to avoid double free

[Yunlong Song]

v1 -> v2: use child_info to pass dentry namelen
v2 -> v3: check child != NULL to include the F2FS_FT_ORPHAN file type
v3 -> v4: fix the i_namelen problem of dump.f2fs

Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
---
 fsck/fsck.c | 28 +++++++++++++++++++++++-----
 fsck/fsck.h |  3 ++-
 2 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/fsck/fsck.c b/fsck/fsck.c
index 2212aa3..5407cf2 100644
--- a/fsck/fsck.c
+++ b/fsck/fsck.c
@@ -539,7 +539,7 @@ int fsck_chk_node_blk(struct f2fs_sb_info *sbi, struct f2fs_inode *inode,
 
 		if (sanity_check_inode(sbi, node_blk))
 			goto err;
-		fsck_chk_inode_blk(sbi, nid, ftype, node_blk, blk_cnt, &ni);
+		fsck_chk_inode_blk(sbi, nid, ftype, node_blk, blk_cnt, &ni, child);
 		quota_add_inode_usage(fsck->qctx, nid, &node_blk->i);
 	} else {
 		switch (ntype) {
@@ -633,7 +633,7 @@ unmatched:
 /* start with valid nid and blkaddr */
 void fsck_chk_inode_blk(struct f2fs_sb_info *sbi, u32 nid,
 		enum FILE_TYPE ftype, struct f2fs_node *node_blk,
-		u32 *blk_cnt, struct node_info *ni)
+		u32 *blk_cnt, struct node_info *ni, struct child_info *child_d)
 {
 	struct f2fs_fsck *fsck = F2FS_FSCK(sbi);
 	struct child_info child;
@@ -850,8 +850,23 @@ skip_blkcnt_fix:
 	en = malloc(F2FS_NAME_LEN + 1);
 	ASSERT(en);
 
-	namelen = convert_encrypted_name(node_blk->i.i_name,
-					le32_to_cpu(node_blk->i.i_namelen),
+	namelen = le32_to_cpu(node_blk->i.i_namelen);
+	if (namelen > F2FS_NAME_LEN) {
+		if (child_d && child_d->i_namelen <= F2FS_NAME_LEN) {
+			ASSERT_MSG("ino: 0x%x has i_namelen: 0x%x, "
+					"but has %d characters for name",
+					nid, namelen, child_d->i_namelen);
+			if (c.fix_on) {
+				FIX_MSG("[0x%x] i_namelen=0x%x -> 0x%x", nid, namelen,
+					child_d->i_namelen);
+				node_blk->i.i_namelen = cpu_to_le32(child_d->i_namelen);
+				need_fix = 1;
+			}
+			namelen = child_d->i_namelen;
+		} else
+			namelen = F2FS_NAME_LEN;
+	}
+	namelen = convert_encrypted_name(node_blk->i.i_name, namelen,
 					en, file_enc_name(&node_blk->i));
 	en[namelen] = '\0';
 	if (ftype == F2FS_FT_ORPHAN)
@@ -1098,6 +1113,8 @@ int convert_encrypted_name(unsigned char *name, int len,
 				unsigned char *new, int enc_name)
 {
 	if (!enc_name) {
+		if (len > F2FS_NAME_LEN)
+			len = F2FS_NAME_LEN;
 		memcpy(new, name, len);
 		new[len] = 0;
 		return len;
@@ -1414,9 +1431,10 @@ static int __chk_dentries(struct f2fs_sb_info *sbi, struct child_info *child,
 				dentry, max, i, last_blk, enc_name);
 
 		blk_cnt = 1;
+		child->i_namelen = name_len;
 		ret = fsck_chk_node_blk(sbi,
 				NULL, le32_to_cpu(dentry[i].ino),
-				ftype, TYPE_INODE, &blk_cnt, NULL);
+				ftype, TYPE_INODE, &blk_cnt, child);
 
 		if (ret && c.fix_on) {
 			int j;
diff --git a/fsck/fsck.h b/fsck/fsck.h
index 0343fbd..d635c5a 100644
--- a/fsck/fsck.h
+++ b/fsck/fsck.h
@@ -54,6 +54,7 @@ struct child_info {
 	u32 pp_ino;		/*parent parent ino*/
 	struct extent_info ei;
 	u32 last_blk;
+	u32 i_namelen;  /* dentry namelen */
 };
 
 struct f2fs_fsck {
@@ -128,7 +129,7 @@ extern int fsck_chk_node_blk(struct f2fs_sb_info *, struct f2fs_inode *, u32,
 		enum FILE_TYPE, enum NODE_TYPE, u32 *,
 		struct child_info *);
 extern void fsck_chk_inode_blk(struct f2fs_sb_info *, u32, enum FILE_TYPE,
-		struct f2fs_node *, u32 *, struct node_info *);
+		struct f2fs_node *, u32 *, struct node_info *, struct child_info *);
 extern int fsck_chk_dnode_blk(struct f2fs_sb_info *, struct f2fs_inode *,
 		u32, enum FILE_TYPE, struct f2fs_node *, u32 *,
 		struct child_info *, struct node_info *);
-- 
1.8.5.2

Re: [PATCH v4] fsck.f2fs: check and fix i_namelen to avoid double free

[Chao Yu]

On 2017/12/18 21:25, Yunlong Song wrote:
> v1 -> v2: use child_info to pass dentry namelen
> v2 -> v3: check child != NULL to include the F2FS_FT_ORPHAN file type
> v3 -> v4: fix the i_namelen problem of dump.f2fs、

There is no commit log, so what do you mean about "avoid double free"?

Other than that, looks good to me.

Reviewed-by: Chao Yu <yuchao0@huawei.com>

Thanks,

Re: [PATCH v4] fsck.f2fs: check and fix i_namelen to avoid double free

[Yunlong Song]

Double free problem:
Since ddr bit jump makes i_namelen a larger value (> 255)，when file is 
not encrypted,
the convert_encrypted_name will memcpy out range of en[255], when en is 
freed, there
will be double free problem.

On 2017/12/23 11:05, Chao Yu wrote:
> On 2017/12/18 21:25, Yunlong Song wrote:
>> v1 -> v2: use child_info to pass dentry namelen
>> v2 -> v3: check child != NULL to include the F2FS_FT_ORPHAN file type
>> v3 -> v4: fix the i_namelen problem of dump.f2fs、
> There is no commit log, so what do you mean about "avoid double free"?
>
> Other than that, looks good to me.
>
> Reviewed-by: Chao Yu <yuchao0@huawei.com>
>
> Thanks,
>
>
> .
>

-- 
Thanks,
Yunlong Song

Re: [PATCH v4] fsck.f2fs: check and fix i_namelen to avoid double free

[Chao Yu]

On 2017/12/23 11:19, Yunlong Song wrote:
> Double free problem:
> Since ddr bit jump makes i_namelen a larger value (> 255)，when file is 
> not encrypted,
> the convert_encrypted_name will memcpy out range of en[255], when en is 
> freed, there
> will be double free problem.

It looks there is only memcpy overflow problem here.

Thanks,

> 
> On 2017/12/23 11:05, Chao Yu wrote:
>> On 2017/12/18 21:25, Yunlong Song wrote:
>>> v1 -> v2: use child_info to pass dentry namelen
>>> v2 -> v3: check child != NULL to include the F2FS_FT_ORPHAN file type
>>> v3 -> v4: fix the i_namelen problem of dump.f2fs、
>> There is no commit log, so what do you mean about "avoid double free"?
>>
>> Other than that, looks good to me.
>>
>> Reviewed-by: Chao Yu <yuchao0@huawei.com>
>>
>> Thanks,
>>
>>
>> .
>>
> 


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Re: [PATCH v4] fsck.f2fs: check and fix i_namelen to avoid double free

[Yunlong Song]

And there is en[namelen] = '\0', should fix namelen to its right value.

On 2017/12/23 11:35, Chao Yu wrote:
> On 2017/12/23 11:19, Yunlong Song wrote:
>> Double free problem:
>> Since ddr bit jump makes i_namelen a larger value (> 255)，when file is
>> not encrypted,
>> the convert_encrypted_name will memcpy out range of en[255], when en is
>> freed, there
>> will be double free problem.
> It looks there is only memcpy overflow problem here.
>
> Thanks,
>
>> On 2017/12/23 11:05, Chao Yu wrote:
>>> On 2017/12/18 21:25, Yunlong Song wrote:
>>>> v1 -> v2: use child_info to pass dentry namelen
>>>> v2 -> v3: check child != NULL to include the F2FS_FT_ORPHAN file type
>>>> v3 -> v4: fix the i_namelen problem of dump.f2fs、
>>> There is no commit log, so what do you mean about "avoid double free"?
>>>
>>> Other than that, looks good to me.
>>>
>>> Reviewed-by: Chao Yu <yuchao0@huawei.com>
>>>
>>> Thanks,
>>>
>>>
>>> .
>>>
>
> .
>

-- 
Thanks,
Yunlong Song