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@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Edward AD <twuufnxlz@xxxxxxxxx> --- 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
