The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y git checkout FETCH_HEAD git cherry-pick -x fc8033a34a3ca7d23353e645e6dde5d364ac5f12 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '167810995913998@kroah.com' --subject-prefix 'PATCH 4.19.y' HEAD^..

Possible dependencies:

fc8033a34a3c ("udf: Preserve link count of system files") 382a2287bf9c ("udf: Remove pointless union in udf_inode_info") 044e2e26f214 ("udf: Avoid accessing uninitialized data on failed inode read") ab9a3a737284 ("udf: reduce leakage of blocks related to named streams") d288d95842f1 ("udf: Fix BUG on corrupted inode")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From fc8033a34a3ca7d23353e645e6dde5d364ac5f12 Mon Sep 17 00:00:00 2001 From: Jan Kara jack@suse.cz Date: Tue, 3 Jan 2023 09:56:56 +0100 Subject: [PATCH] udf: Preserve link count of system files

System files in UDF filesystem have link count 0. To not confuse VFS we fudge the link count to be 1 when reading such inodes however we forget to restore the link count of 0 when writing such inodes. Fix that.

CC: stable@vger.kernel.org Signed-off-by: Jan Kara jack@suse.cz

diff --git a/fs/udf/inode.c b/fs/udf/inode.c index 31965c3798f2..9ee269d3d546 100644 --- a/fs/udf/inode.c +++ b/fs/udf/inode.c @@ -1301,6 +1301,7 @@ static int udf_read_inode(struct inode *inode, bool hidden_inode) ret = -EIO; goto out; } + iinfo->i_hidden = hidden_inode; iinfo->i_unique = 0; iinfo->i_lenEAttr = 0; iinfo->i_lenExtents = 0; @@ -1636,8 +1637,12 @@ static int udf_update_inode(struct inode *inode, int do_sync)

if (S_ISDIR(inode->i_mode) && inode->i_nlink > 0) fe->fileLinkCount = cpu_to_le16(inode->i_nlink - 1); - else - fe->fileLinkCount = cpu_to_le16(inode->i_nlink); + else { + if (iinfo->i_hidden) + fe->fileLinkCount = cpu_to_le16(0); + else + fe->fileLinkCount = cpu_to_le16(inode->i_nlink); + }

fe->informationLength = cpu_to_le64(inode->i_size);

diff --git a/fs/udf/super.c b/fs/udf/super.c index 06eda8177b5f..241b40e886b3 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -147,6 +147,7 @@ static struct inode *udf_alloc_inode(struct super_block *sb) ei->i_next_alloc_goal = 0; ei->i_strat4096 = 0; ei->i_streamdir = 0; + ei->i_hidden = 0; init_rwsem(&ei->i_data_sem); ei->cached_extent.lstart = -1; spin_lock_init(&ei->i_extent_cache_lock); diff --git a/fs/udf/udf_i.h b/fs/udf/udf_i.h index 06ff7006b822..312b7c9ef10e 100644 --- a/fs/udf/udf_i.h +++ b/fs/udf/udf_i.h @@ -44,7 +44,8 @@ struct udf_inode_info { unsigned i_use : 1; /* unallocSpaceEntry */ unsigned i_strat4096 : 1; unsigned i_streamdir : 1; - unsigned reserved : 25; + unsigned i_hidden : 1; /* hidden system inode */ + unsigned reserved : 24; __u8 *i_data; struct kernel_lb_addr i_locStreamdir; __u64 i_lenStreams;