1 files changed, 75 insertions, 68 deletions

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index d77be9e9f535..996e7900d4c8 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -131,31 +131,26 @@ static __le32 ext4_xattr_block_csum(struct inode *inode,
 }
 
 static int ext4_xattr_block_csum_verify(struct inode *inode,
-					sector_t block_nr,
-					struct ext4_xattr_header *hdr)
+					struct buffer_head *bh)
 {
-	if (ext4_has_metadata_csum(inode->i_sb) &&
-	    (hdr->h_checksum != ext4_xattr_block_csum(inode, block_nr, hdr)))
-		return 0;
-	return 1;
-}
-
-static void ext4_xattr_block_csum_set(struct inode *inode,
-				      sector_t block_nr,
-				      struct ext4_xattr_header *hdr)
-{
-	if (!ext4_has_metadata_csum(inode->i_sb))
-		return;
+	struct ext4_xattr_header *hdr = BHDR(bh);
+	int ret = 1;
 
-	hdr->h_checksum = ext4_xattr_block_csum(inode, block_nr, hdr);
+	if (ext4_has_metadata_csum(inode->i_sb)) {
+		lock_buffer(bh);
+		ret = (hdr->h_checksum == ext4_xattr_block_csum(inode,
+							bh->b_blocknr, hdr));
+		unlock_buffer(bh);
+	}
+	return ret;
 }
 
-static inline int ext4_handle_dirty_xattr_block(handle_t *handle,
-						struct inode *inode,
-						struct buffer_head *bh)
+static void ext4_xattr_block_csum_set(struct inode *inode,
+				      struct buffer_head *bh)
 {
-	ext4_xattr_block_csum_set(inode, bh->b_blocknr, BHDR(bh));
-	return ext4_handle_dirty_metadata(handle, inode, bh);
+	if (ext4_has_metadata_csum(inode->i_sb))
+		BHDR(bh)->h_checksum = ext4_xattr_block_csum(inode,
+						bh->b_blocknr, BHDR(bh));
 }
 
 static inline const struct xattr_handler *
@@ -185,6 +180,7 @@ ext4_xattr_check_names(struct ext4_xattr_entry *entry, void *end,
 {
 	struct ext4_xattr_entry *e = entry;
 
+	/* Find the end of the names list */
 	while (!IS_LAST_ENTRY(e)) {
 		struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e);
 		if ((void *)next >= end)
@@ -192,15 +188,29 @@ ext4_xattr_check_names(struct ext4_xattr_entry *entry, void *end,
 		e = next;
 	}
 
+	/* Check the values */
 	while (!IS_LAST_ENTRY(entry)) {
 		if (entry->e_value_block != 0)
 			return -EFSCORRUPTED;
-		if (entry->e_value_size != 0 &&
-		    (value_start + le16_to_cpu(entry->e_value_offs) <
-		     (void *)e + sizeof(__u32) ||
-		     value_start + le16_to_cpu(entry->e_value_offs) +
-		    le32_to_cpu(entry->e_value_size) > end))
-			return -EFSCORRUPTED;
+		if (entry->e_value_size != 0) {
+			u16 offs = le16_to_cpu(entry->e_value_offs);
+			u32 size = le32_to_cpu(entry->e_value_size);
+			void *value;
+
+			/*
+			 * The value cannot overlap the names, and the value
+			 * with padding cannot extend beyond 'end'.  Check both
+			 * the padded and unpadded sizes, since the size may
+			 * overflow to 0 when adding padding.
+			 */
+			if (offs > end - value_start)
+				return -EFSCORRUPTED;
+			value = value_start + offs;
+			if (value < (void *)e + sizeof(u32) ||
+			    size > end - value ||
+			    EXT4_XATTR_SIZE(size) > end - value)
+				return -EFSCORRUPTED;
+		}
 		entry = EXT4_XATTR_NEXT(entry);
 	}
 
@@ -218,7 +228,7 @@ ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh)
 	if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
 	    BHDR(bh)->h_blocks != cpu_to_le32(1))
 		return -EFSCORRUPTED;
-	if (!ext4_xattr_block_csum_verify(inode, bh->b_blocknr, BHDR(bh)))
+	if (!ext4_xattr_block_csum_verify(inode, bh))
 		return -EFSBADCRC;
 	error = ext4_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size,
 				       bh->b_data);
@@ -231,13 +241,12 @@ static int
 __xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header,
 			 void *end, const char *function, unsigned int line)
 {
-	struct ext4_xattr_entry *entry = IFIRST(header);
 	int error = -EFSCORRUPTED;
 
-	if (((void *) header >= end) ||
+	if (end - (void *)header < sizeof(*header) + sizeof(u32) ||
 	    (header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)))
 		goto errout;
-	error = ext4_xattr_check_names(entry, end, entry);
+	error = ext4_xattr_check_names(IFIRST(header), end, IFIRST(header));
 errout:
 	if (error)
 		__ext4_error_inode(inode, function, line, 0,
@@ -397,6 +406,9 @@ ext4_xattr_get(struct inode *inode, int name_index, const char *name,
 {
 	int error;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+		return -EIO;
+
 	if (strlen(name) > 255)
 		return -ERANGE;
 
@@ -601,23 +613,22 @@ ext4_xattr_release_block(handle_t *handle, struct inode *inode,
 			}
 		}
 
+		ext4_xattr_block_csum_set(inode, bh);
 		/*
 		 * Beware of this ugliness: Releasing of xattr block references
 		 * from different inodes can race and so we have to protect
 		 * from a race where someone else frees the block (and releases
 		 * its journal_head) before we are done dirtying the buffer. In
 		 * nojournal mode this race is harmless and we actually cannot
-		 * call ext4_handle_dirty_xattr_block() with locked buffer as
+		 * call ext4_handle_dirty_metadata() with locked buffer as
 		 * that function can call sync_dirty_buffer() so for that case
 		 * we handle the dirtying after unlocking the buffer.
 		 */
 		if (ext4_handle_valid(handle))
-			error = ext4_handle_dirty_xattr_block(handle, inode,
-							      bh);
+			error = ext4_handle_dirty_metadata(handle, inode, bh);
 		unlock_buffer(bh);
 		if (!ext4_handle_valid(handle))
-			error = ext4_handle_dirty_xattr_block(handle, inode,
-							      bh);
+			error = ext4_handle_dirty_metadata(handle, inode, bh);
 		if (IS_SYNC(inode))
 			ext4_handle_sync(handle);
 		dquot_free_block(inode, EXT4_C2B(EXT4_SB(inode->i_sb), 1));
@@ -846,13 +857,14 @@ ext4_xattr_block_set(handle_t *handle, struct inode *inode,
 				ext4_xattr_cache_insert(ext4_mb_cache,
 					bs->bh);
 			}
+			ext4_xattr_block_csum_set(inode, bs->bh);
 			unlock_buffer(bs->bh);
 			if (error == -EFSCORRUPTED)
 				goto bad_block;
 			if (!error)
-				error = ext4_handle_dirty_xattr_block(handle,
-								      inode,
-								      bs->bh);
+				error = ext4_handle_dirty_metadata(handle,
+								   inode,
+								   bs->bh);
 			if (error)
 				goto cleanup;
 			goto inserted;
@@ -950,10 +962,11 @@ inserted:
 					ce->e_reusable = 0;
 				ea_bdebug(new_bh, "reusing; refcount now=%d",
 					  ref);
+				ext4_xattr_block_csum_set(inode, new_bh);
 				unlock_buffer(new_bh);
-				error = ext4_handle_dirty_xattr_block(handle,
-								      inode,
-								      new_bh);
+				error = ext4_handle_dirty_metadata(handle,
+								   inode,
+								   new_bh);
 				if (error)
 					goto cleanup_dquot;
 			}
@@ -1003,11 +1016,12 @@ getblk_failed:
 				goto getblk_failed;
 			}
 			memcpy(new_bh->b_data, s->base, new_bh->b_size);
+			ext4_xattr_block_csum_set(inode, new_bh);
 			set_buffer_uptodate(new_bh);
 			unlock_buffer(new_bh);
 			ext4_xattr_cache_insert(ext4_mb_cache, new_bh);
-			error = ext4_handle_dirty_xattr_block(handle,
-							      inode, new_bh);
+			error = ext4_handle_dirty_metadata(handle, inode,
+							   new_bh);
 			if (error)
 				goto cleanup;
 		}
@@ -1109,7 +1123,7 @@ int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode,
 	return 0;
 }
 
-static int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
+static int ext4_xattr_ibody_set(struct inode *inode,
 				struct ext4_xattr_info *i,
 				struct ext4_xattr_ibody_find *is)
 {
@@ -1174,16 +1188,14 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
 	struct ext4_xattr_block_find bs = {
 		.s = { .not_found = -ENODATA, },
 	};
-	unsigned long no_expand;
+	int no_expand;
 	int error;
 
 	if (!name)
 		return -EINVAL;
 	if (strlen(name) > 255)
 		return -ERANGE;
-	down_write(&EXT4_I(inode)->xattr_sem);
-	no_expand = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND);
-	ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
+	ext4_write_lock_xattr(inode, &no_expand);
 
 	error = ext4_reserve_inode_write(handle, inode, &is.iloc);
 	if (error)
@@ -1216,7 +1228,7 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
 	}
 	if (!value) {
 		if (!is.s.not_found)
-			error = ext4_xattr_ibody_set(handle, inode, &i, &is);
+			error = ext4_xattr_ibody_set(inode, &i, &is);
 		else if (!bs.s.not_found)
 			error = ext4_xattr_block_set(handle, inode, &i, &bs);
 	} else {
@@ -1227,7 +1239,7 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
 		if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i))
 			goto cleanup;
 
-		error = ext4_xattr_ibody_set(handle, inode, &i, &is);
+		error = ext4_xattr_ibody_set(inode, &i, &is);
 		if (!error && !bs.s.not_found) {
 			i.value = NULL;
 			error = ext4_xattr_block_set(handle, inode, &i, &bs);
@@ -1242,16 +1254,15 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
 				goto cleanup;
 			if (!is.s.not_found) {
 				i.value = NULL;
-				error = ext4_xattr_ibody_set(handle, inode, &i,
-							     &is);
+				error = ext4_xattr_ibody_set(inode, &i, &is);
 			}
 		}
 	}
 	if (!error) {
 		ext4_xattr_update_super_block(handle, inode->i_sb);
-		inode->i_ctime = ext4_current_time(inode);
+		inode->i_ctime = current_time(inode);
 		if (!value)
-			ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
+			no_expand = 0;
 		error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
 		/*
 		 * The bh is consumed by ext4_mark_iloc_dirty, even with
@@ -1265,9 +1276,7 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
 cleanup:
 	brelse(is.iloc.bh);
 	brelse(bs.bh);
-	if (no_expand == 0)
-		ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
-	up_write(&EXT4_I(inode)->xattr_sem);
+	ext4_write_unlock_xattr(inode, &no_expand);
 	return error;
 }
 
@@ -1384,7 +1393,7 @@ static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
 		goto out;
 
 	/* Remove the chosen entry from the inode */
-	error = ext4_xattr_ibody_set(handle, inode, &i, is);
+	error = ext4_xattr_ibody_set(inode, &i, is);
 	if (error)
 		goto out;
 
@@ -1484,12 +1493,11 @@ int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
 	int error = 0, tried_min_extra_isize = 0;
 	int s_min_extra_isize = le16_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_min_extra_isize);
 	int isize_diff;	/* How much do we need to grow i_extra_isize */
+	int no_expand;
+
+	if (ext4_write_trylock_xattr(inode, &no_expand) == 0)
+		return 0;
 
-	down_write(&EXT4_I(inode)->xattr_sem);
-	/*
-	 * Set EXT4_STATE_NO_EXPAND to avoid recursion when marking inode dirty
-	 */
-	ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
 retry:
 	isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize;
 	if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
@@ -1571,17 +1579,16 @@ shift:
 	EXT4_I(inode)->i_extra_isize = new_extra_isize;
 	brelse(bh);
 out:
-	ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
-	up_write(&EXT4_I(inode)->xattr_sem);
+	ext4_write_unlock_xattr(inode, &no_expand);
 	return 0;
 
 cleanup:
 	brelse(bh);
 	/*
-	 * We deliberately leave EXT4_STATE_NO_EXPAND set here since inode
-	 * size expansion failed.
+	 * Inode size expansion failed; don't try again
 	 */
-	up_write(&EXT4_I(inode)->xattr_sem);
+	no_expand = 1;
+	ext4_write_unlock_xattr(inode, &no_expand);
 	return error;
 }