Commit 382005dd authored Jun 06, 2023 by Dave Chinner Committed by Long Li Jun 06, 2023

xfs: validate inode fork size against fork format

stable inclusion
from stable-v5.10.145
commit dce466286944389dd77b314e0d1eea6969d0e4d4
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I685FC
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=tags/v5.10.146&id=dce466286944389dd77b314e0d1eea6969d0e4d4



--------------------------------

commit 1eb70f54 upstream.

[backport for 5.10.y]

xfs_repair catches fork size/format mismatches, but the in-kernel
verifier doesn't, leading to null pointer failures when attempting
to perform operations on the fork. This can occur in the
xfs_dir_is_empty() where the in-memory fork format does not match
the size and so the fork data pointer is accessed incorrectly.

Note: this causes new failures in xfs/348 which is testing mode vs
ftype mismatches. We now detect a regular file that has been changed
to a directory or symlink mode as being corrupt because the data
fork is for a symlink or directory should be in local form when
there are only 3 bytes of data in the data fork. Hence the inode
verify for the regular file now fires w/ -EFSCORRUPTED because
the inode fork format does not match the format the corrupted mode
says it should be in.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Long Li <leo.lilong@huawei.com>

parent e5008e01

fs/xfs/libxfs/xfs_inode_buf.c

+26 −9

Original line number	Diff line number	Diff line
		@@ -357,19 +357,36 @@ xfs_dinode_verify_fork(
		int whichfork)
		{
		uint32_t di_nextents = XFS_DFORK_NEXTENTS(dip, whichfork);
		mode_t mode = be16_to_cpu(dip->di_mode);
		uint32_t fork_size = XFS_DFORK_SIZE(dip, mp, whichfork);
		uint32_t fork_format = XFS_DFORK_FORMAT(dip, whichfork);

		switch (XFS_DFORK_FORMAT(dip, whichfork)) {
		case XFS_DINODE_FMT_LOCAL:
		/*
		* no local regular files yet
		* For fork types that can contain local data, check that the fork
		* format matches the size of local data contained within the fork.
		*
		* For all types, check that when the size says the should be in extent
		* or btree format, the inode isn't claiming it is in local format.
		*/
		if (whichfork == XFS_DATA_FORK) {
		if (S_ISREG(be16_to_cpu(dip->di_mode)))
		if (S_ISDIR(mode) \|\| S_ISLNK(mode)) {
		if (be64_to_cpu(dip->di_size) <= fork_size &&
		fork_format != XFS_DINODE_FMT_LOCAL)
		return __this_address;
		if (be64_to_cpu(dip->di_size) >
		XFS_DFORK_SIZE(dip, mp, whichfork))
		}

		if (be64_to_cpu(dip->di_size) > fork_size &&
		fork_format == XFS_DINODE_FMT_LOCAL)
		return __this_address;
		}

		switch (fork_format) {
		case XFS_DINODE_FMT_LOCAL:
		/*
		* No local regular files yet.
		*/
		if (S_ISREG(mode) && whichfork == XFS_DATA_FORK)
		return __this_address;
		if (di_nextents)
		return __this_address;
		break;