From 00a8e60851676d84107e17f04b576146fc8e665e Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Mon, 22 May 2023 19:07:13 +0100 Subject: [PATCH] 4.14-stable patches added patches: nilfs2-fix-use-after-free-bug-of-nilfs_root-in-nilfs_evict_inode.patch --- ...g-of-nilfs_root-in-nilfs_evict_inode.patch | 65 +++++++++++++++++++ queue-4.14/series | 1 + 2 files changed, 66 insertions(+) create mode 100644 queue-4.14/nilfs2-fix-use-after-free-bug-of-nilfs_root-in-nilfs_evict_inode.patch diff --git a/queue-4.14/nilfs2-fix-use-after-free-bug-of-nilfs_root-in-nilfs_evict_inode.patch b/queue-4.14/nilfs2-fix-use-after-free-bug-of-nilfs_root-in-nilfs_evict_inode.patch new file mode 100644 index 00000000000..c7b275e9668 --- /dev/null +++ b/queue-4.14/nilfs2-fix-use-after-free-bug-of-nilfs_root-in-nilfs_evict_inode.patch @@ -0,0 +1,65 @@ +From 9b5a04ac3ad9898c4745cba46ea26de74ba56a8e Mon Sep 17 00:00:00 2001 +From: Ryusuke Konishi +Date: Wed, 10 May 2023 00:29:56 +0900 +Subject: nilfs2: fix use-after-free bug of nilfs_root in nilfs_evict_inode() + +From: Ryusuke Konishi + +commit 9b5a04ac3ad9898c4745cba46ea26de74ba56a8e upstream. + +During unmount process of nilfs2, nothing holds nilfs_root structure after +nilfs2 detaches its writer in nilfs_detach_log_writer(). However, since +nilfs_evict_inode() uses nilfs_root for some cleanup operations, it may +cause use-after-free read if inodes are left in "garbage_list" and +released by nilfs_dispose_list() at the end of nilfs_detach_log_writer(). + +Fix this issue by modifying nilfs_evict_inode() to only clear inode +without additional metadata changes that use nilfs_root if the file system +is degraded to read-only or the writer is detached. + +Link: https://lkml.kernel.org/r/20230509152956.8313-1-konishi.ryusuke@gmail.com +Signed-off-by: Ryusuke Konishi +Reported-by: syzbot+78d4495558999f55d1da@syzkaller.appspotmail.com +Closes: https://lkml.kernel.org/r/00000000000099e5ac05fb1c3b85@google.com +Tested-by: Ryusuke Konishi +Cc: +Signed-off-by: Andrew Morton +Signed-off-by: Greg Kroah-Hartman +--- + fs/nilfs2/inode.c | 18 ++++++++++++++++++ + 1 file changed, 18 insertions(+) + +--- a/fs/nilfs2/inode.c ++++ b/fs/nilfs2/inode.c +@@ -939,6 +939,7 @@ void nilfs_evict_inode(struct inode *ino + struct nilfs_transaction_info ti; + struct super_block *sb = inode->i_sb; + struct nilfs_inode_info *ii = NILFS_I(inode); ++ struct the_nilfs *nilfs; + int ret; + + if (inode->i_nlink || !ii->i_root || unlikely(is_bad_inode(inode))) { +@@ -951,6 +952,23 @@ void nilfs_evict_inode(struct inode *ino + + truncate_inode_pages_final(&inode->i_data); + ++ nilfs = sb->s_fs_info; ++ if (unlikely(sb_rdonly(sb) || !nilfs->ns_writer)) { ++ /* ++ * If this inode is about to be disposed after the file system ++ * has been degraded to read-only due to file system corruption ++ * or after the writer has been detached, do not make any ++ * changes that cause writes, just clear it. ++ * Do this check after read-locking ns_segctor_sem by ++ * nilfs_transaction_begin() in order to avoid a race with ++ * the writer detach operation. ++ */ ++ clear_inode(inode); ++ nilfs_clear_inode(inode); ++ nilfs_transaction_abort(sb); ++ return; ++ } ++ + /* TODO: some of the following operations may fail. */ + nilfs_truncate_bmap(ii, 0); + nilfs_mark_inode_dirty(inode); diff --git a/queue-4.14/series b/queue-4.14/series index 79037d430f0..0ebbf04a8ec 100644 --- a/queue-4.14/series +++ b/queue-4.14/series @@ -50,3 +50,4 @@ alsa-hda-add-nvidia-codec-ids-a3-through-a7-to-patch-table.patch statfs-enforce-statfs-structure-initialization.patch serial-add-support-for-advantech-pci-1611u-card.patch ceph-force-updating-the-msg-pointer-in-non-split-case.patch +nilfs2-fix-use-after-free-bug-of-nilfs_root-in-nilfs_evict_inode.patch -- 2.47.3