From: Jaegeuk Kim jaegeuk@kernel.org
[ Upstream commit 4e240d1bab1ead280ddf5eb05058dba6bbd57d10 ]
If namelen is corrupted to have very long value, fill_dentries can copy wrong memory area.
Reviewed-by: Chao Yu yuchao0@huawei.com Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/f2fs/dir.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c index b414892be08b7..79d138756acb5 100644 --- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -843,6 +843,16 @@ bool f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d, de_name.name = d->filename[bit_pos]; de_name.len = le16_to_cpu(de->name_len);
+ /* check memory boundary before moving forward */ + bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len)); + if (unlikely(bit_pos > d->max)) { + f2fs_msg(F2FS_I_SB(d->inode)->sb, KERN_WARNING, + "%s: corrupted namelen=%d, run fsck to fix.", + __func__, le16_to_cpu(de->name_len)); + set_sbi_flag(F2FS_I_SB(d->inode)->sb->s_fs_info, SBI_NEED_FSCK); + return -EINVAL; + } + if (f2fs_encrypted_inode(d->inode)) { int save_len = fstr->len; int err; @@ -861,7 +871,6 @@ bool f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d, le32_to_cpu(de->ino), d_type)) return true;
- bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len)); ctx->pos = start_pos + bit_pos; } return false;