Re: [syzbot] Re: [syzbot] [ext4?] kernel BUG in ext4_write_inline_data (2)

syzbot
2024-11-22T16:43:07Z

linux-kernel@vger.kernel.org.

***

Subject: Re: [syzbot] [ext4?] kernel BUG in ext4_write_inline_data (2)
Author: bretznic@gmail.com

#syz test

--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -3562,6 +3562,12 @@ extern int ext4_get_max_inline_size(struct inode *inode);
extern int ext4_find_inline_data_nolock(struct inode *inode);
extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);

+static inline bool ext4_inline_possible(struct inode *inode,
+ loff_t pos, unsigned int len)
+{
+ return pos + len <= ext4_get_max_inline_size(inode);
+}
+
int ext4_readpage_inline(struct inode *inode, struct folio *folio);
extern int ext4_try_to_write_inline_data(struct address_space *mapping,
struct inode *inode,
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index 3536ca7e4fcc..ec25f066a2c2 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -668,7 +668,7 @@ int ext4_try_to_write_inline_data(struct
address_space *mapping,
struct folio *folio;
struct ext4_iloc iloc;

- if (pos + len > ext4_get_max_inline_size(inode))
+ if (!ext4_inline_possible(inode, pos, len))
goto convert;

ret = ext4_get_inode_loc(inode, &iloc);
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 54bdd4884fe6..d4c0e0a42b8e 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3061,7 +3061,8 @@ static int ext4_da_write_end(struct file *file,