2019-06-12 09:21:30

by Randall Huang

Subject: [PATCH] f2fs: add boundary check in inline_data_addr

Add boundary check in case of extra_size is larger
than sizeof array "i_addr"

Signed-off-by: Randall Huang <[email protected]>
---
fs/f2fs/f2fs.h | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 760390f380b6..17f3858a00c3 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -2660,11 +2660,25 @@ static inline bool f2fs_is_drop_cache(struct inode *inode)
return is_inode_flag_set(inode, FI_DROP_CACHE);
}

+#define F2FS_TOTAL_EXTRA_ATTR_SIZE \
+ (offsetof(struct f2fs_inode, i_extra_end) - \
+ offsetof(struct f2fs_inode, i_extra_isize)) \
+
static inline void *inline_data_addr(struct inode *inode, struct page *page)
{
struct f2fs_inode *ri = F2FS_INODE(page);
int extra_size = get_extra_isize(inode);

+ if (extra_size < 0 || extra_size > F2FS_TOTAL_EXTRA_ATTR_SIZE ||
+ extra_size % sizeof(__le32)) {
+ f2fs_msg(F2FS_I_SB(inode)->sb, KERN_ERR,
+ "%s: inode (ino=%lx) has corrupted i_extra_isize: %d, "
+ "max: %zu",
+ __func__, inode->i_ino, extra_size,
+ F2FS_TOTAL_EXTRA_ATTR_SIZE);
+ extra_size = 0;
+ }
+
return (void *)&(ri->i_addr[extra_size + DEF_INLINE_RESERVED_SIZE]);
}

@@ -2817,10 +2831,6 @@ static inline int get_inline_xattr_addrs(struct inode *inode)
((is_inode_flag_set(i, FI_ACL_MODE)) ? \
(F2FS_I(i)->i_acl_mode) : ((i)->i_mode))

-#define F2FS_TOTAL_EXTRA_ATTR_SIZE \
- (offsetof(struct f2fs_inode, i_extra_end) - \
- offsetof(struct f2fs_inode, i_extra_isize)) \
-
#define F2FS_OLD_ATTRIBUTE_SIZE (offsetof(struct f2fs_inode, i_addr))
#define F2FS_FITS_IN_INODE(f2fs_inode, extra_isize, field) \
((offsetof(typeof(*(f2fs_inode)), field) + \
--
2.22.0.rc2.383.gf4fbbf30c2-goog

2019-06-13 16:39:35

by Chao Yu

Subject: Re: [PATCH] f2fs: add boundary check in inline_data_addr

Hi Randall,

On 2019/6/12 16:58, Randall Huang wrote:
> Add boundary check in case of extra_size is larger
> than sizeof array "i_addr"
>
> Signed-off-by: Randall Huang <[email protected]>
> ---
> fs/f2fs/f2fs.h | 18 ++++++++++++++----
> 1 file changed, 14 insertions(+), 4 deletions(-)
>
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 760390f380b6..17f3858a00c3 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -2660,11 +2660,25 @@ static inline bool f2fs_is_drop_cache(struct inode *inode)
> return is_inode_flag_set(inode, FI_DROP_CACHE);
> }
>
> +#define F2FS_TOTAL_EXTRA_ATTR_SIZE \
> + (offsetof(struct f2fs_inode, i_extra_end) - \
> + offsetof(struct f2fs_inode, i_extra_isize)) \
> +
> static inline void *inline_data_addr(struct inode *inode, struct page *page)
> {
> struct f2fs_inode *ri = F2FS_INODE(page);
> int extra_size = get_extra_isize(inode);
>
> + if (extra_size < 0 || extra_size > F2FS_TOTAL_EXTRA_ATTR_SIZE ||
> + extra_size % sizeof(__le32)) {
> + f2fs_msg(F2FS_I_SB(inode)->sb, KERN_ERR,
> + "%s: inode (ino=%lx) has corrupted i_extra_isize: %d, "
> + "max: %zu",
> + __func__, inode->i_ino, extra_size,
> + F2FS_TOTAL_EXTRA_ATTR_SIZE);
> + extra_size = 0;
> + }

Oh, we have already did the sanity check on .i_extra_isize field in
sanity_check_inode(), why can it be changed after that? bit-transition of cache
or memory overflow?

Thanks,

> +
> return (void *)&(ri->i_addr[extra_size + DEF_INLINE_RESERVED_SIZE]);
> }
>
> @@ -2817,10 +2831,6 @@ static inline int get_inline_xattr_addrs(struct inode *inode)
> ((is_inode_flag_set(i, FI_ACL_MODE)) ? \
> (F2FS_I(i)->i_acl_mode) : ((i)->i_mode))
>
> -#define F2FS_TOTAL_EXTRA_ATTR_SIZE \
> - (offsetof(struct f2fs_inode, i_extra_end) - \
> - offsetof(struct f2fs_inode, i_extra_isize)) \
> -
> #define F2FS_OLD_ATTRIBUTE_SIZE (offsetof(struct f2fs_inode, i_addr))
> #define F2FS_FITS_IN_INODE(f2fs_inode, extra_isize, field) \
> ((offsetof(typeof(*(f2fs_inode)), field) + \
>