The memory allocated to s_vhdr_buf in the function hfsplus-read_wrapper is
too small, resulting in a slab out of bounds issue when copying data with
copy_page_from_iter_atomic.
When allocating memory to s_vhdr_buf, take the maximum value between
hfsplus_min_io_size(sb) and PAGE_SIZE to avoid similar issues.
Reported-and-tested-by: syzbot+4a2376bc62e59406c414@syzkaller.appspotmail.com
Signed-off-by: Edward AD <twuufnxlz@gmail.com>
---
fs/hfsplus/wrapper.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/fs/hfsplus/wrapper.c b/fs/hfsplus/wrapper.c
index 0b791adf02e5..56bee8dbe532 100644
--- a/fs/hfsplus/wrapper.c
+++ b/fs/hfsplus/wrapper.c
@@ -163,7 +163,7 @@ int hfsplus_read_wrapper(struct super_block *sb)
struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
struct hfsplus_wd wd;
sector_t part_start, part_size;
- u32 blocksize;
+ u32 blocksize, bufsize;
int error = 0;
error = -EINVAL;
@@ -175,10 +175,11 @@ int hfsplus_read_wrapper(struct super_block *sb)
goto out;
error = -ENOMEM;
- sbi->s_vhdr_buf = kmalloc(hfsplus_min_io_size(sb), GFP_KERNEL);
+ bufsize = max_t(u32, hfsplus_min_io_size(sb), PAGE_SIZE);
+ sbi->s_vhdr_buf = kmalloc(bufsize, GFP_KERNEL);
if (!sbi->s_vhdr_buf)
goto out;
- sbi->s_backup_vhdr_buf = kmalloc(hfsplus_min_io_size(sb), GFP_KERNEL);
+ sbi->s_backup_vhdr_buf = kmalloc(bufsize, GFP_KERNEL);
if (!sbi->s_backup_vhdr_buf)
goto out_free_vhdr;
--
2.25.1