From 9ec5a534d77c340387af485b311b39d7a186b105 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Thu, 22 Sep 2022 08:15:01 -0700 Subject: [PATCH] xfs: validate inode fork size against fork format [ Upstream commit 1eb70f54c445fcbb25817841e774adb3d912f3e8 ] 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 Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Dave Chinner Signed-off-by: Leah Rumancik Acked-by: Darrick J. Wong Signed-off-by: Greg Kroah-Hartman --- fs/xfs/libxfs/xfs_inode_buf.c | 35 ++++++++++++++++++++++++++--------- 1 file changed, 26 insertions(+), 9 deletions(-) diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c index 3932b4e..f84d3fb 100644 --- a/fs/xfs/libxfs/xfs_inode_buf.c +++ b/fs/xfs/libxfs/xfs_inode_buf.c @@ -337,19 +337,36 @@ 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)) { + /* + * 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_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) > fork_size && + fork_format == XFS_DINODE_FMT_LOCAL) + return __this_address; + } + + switch (fork_format) { case XFS_DINODE_FMT_LOCAL: /* - * no local regular files yet + * No local regular files yet. */ - if (whichfork == XFS_DATA_FORK) { - if (S_ISREG(be16_to_cpu(dip->di_mode))) - return __this_address; - if (be64_to_cpu(dip->di_size) > - XFS_DFORK_SIZE(dip, mp, whichfork)) - return __this_address; - } + if (S_ISREG(mode) && whichfork == XFS_DATA_FORK) + return __this_address; if (di_nextents) return __this_address; break; -- 2.7.4