From 3c6f46eacd876bd723a9bad3c6882714c052fd8e Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Tue, 17 Jan 2017 11:41:41 -0800 Subject: xfs: sanity check directory inode di_size This changes fixes an assertion hit when fuzzing on-disk i_mode values. The easy case to fix is when changing an empty file i_mode to S_IFDIR. In this case, xfs_dinode_verify() detects an illegal zero size for directory and fails to load the inode structure from disk. For the case of non empty file whose i_mode is changed to S_IFDIR, the ASSERT() statement in xfs_dir2_isblock() is replaced with return -EFSCORRUPTED, to avoid interacting with corrupted jusk also when XFS_DEBUG is disabled. Suggested-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Signed-off-by: Amir Goldstein Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/libxfs/xfs_inode_buf.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'fs/xfs/libxfs/xfs_inode_buf.c') diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c index dd483e2767f7..0091ac3f5241 100644 --- a/fs/xfs/libxfs/xfs_inode_buf.c +++ b/fs/xfs/libxfs/xfs_inode_buf.c @@ -386,6 +386,7 @@ xfs_dinode_verify( xfs_ino_t ino, struct xfs_dinode *dip) { + uint16_t mode; uint16_t flags; uint64_t flags2; @@ -396,8 +397,10 @@ xfs_dinode_verify( if (be64_to_cpu(dip->di_size) & (1ULL << 63)) return false; - /* No zero-length symlinks. */ - if (S_ISLNK(be16_to_cpu(dip->di_mode)) && dip->di_size == 0) + mode = be16_to_cpu(dip->di_mode); + + /* No zero-length symlinks/dirs. */ + if ((S_ISLNK(mode) || S_ISDIR(mode)) && dip->di_size == 0) return false; /* only version 3 or greater inodes are extensively verified here */ -- cgit v1.2.3 From a324cbf10a3c67aaa10c9f47f7b5801562925bc2 Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Tue, 17 Jan 2017 11:41:44 -0800 Subject: xfs: sanity check inode di_mode Check for invalid file type in xfs_dinode_verify() and fail to load the inode structure from disk. Reviewed-by: Darrick J. Wong Signed-off-by: Amir Goldstein Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/libxfs/xfs_inode_buf.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'fs/xfs/libxfs/xfs_inode_buf.c') diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c index 0091ac3f5241..d93f9d918cfc 100644 --- a/fs/xfs/libxfs/xfs_inode_buf.c +++ b/fs/xfs/libxfs/xfs_inode_buf.c @@ -29,6 +29,7 @@ #include "xfs_icache.h" #include "xfs_trans.h" #include "xfs_ialloc.h" +#include "xfs_dir2.h" /* * Check that none of the inode's in the buffer have a next @@ -398,6 +399,8 @@ xfs_dinode_verify( return false; mode = be16_to_cpu(dip->di_mode); + if (mode && xfs_mode_to_ftype(mode) == XFS_DIR3_FT_UNKNOWN) + return false; /* No zero-length symlinks/dirs. */ if ((S_ISLNK(mode) || S_ISDIR(mode)) && dip->di_size == 0) -- cgit v1.2.3