On Thu, Aug 20, 2020 at 11:21:27AM +0200, Greg Kroah-Hartman wrote:
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 92a240616f520..5411d6667781f 100644 --- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -805,6 +805,16 @@ 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 ret;
@@ -829,7 +839,6 @@ 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));
This buggy backport broke f2fs encryption in 4.4-stable, due to a missing prerequisite commit (https://lkml.kernel.org/stable/20201031195809.377983-1-ebiggers@kernel.org/). Why didn't this backport get Cc'ed to the subsystem mailing list? It wasn't even a clean cherry pick.
- Eric