1 files changed, 72 insertions, 55 deletions

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 3b69330a4250..499cb4b1fbd2 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * linux/fs/ext4/xattr.c
  *
@@ -55,6 +56,7 @@
 #include <linux/slab.h>
 #include <linux/mbcache.h>
 #include <linux/quotaops.h>
+#include <linux/iversion.h>
 #include "ext4_jbd2.h"
 #include "ext4.h"
 #include "xattr.h"
@@ -193,10 +195,13 @@ ext4_xattr_check_entries(struct ext4_xattr_entry *entry, void *end,
 
 	/* Check the values */
 	while (!IS_LAST_ENTRY(entry)) {
-		if (entry->e_value_size != 0 &&
-		    entry->e_value_inum == 0) {
+		u32 size = le32_to_cpu(entry->e_value_size);
+
+		if (size > EXT4_XATTR_SIZE_MAX)
+			return -EFSCORRUPTED;
+
+		if (size != 0 && entry->e_value_inum == 0) {
 			u16 offs = le16_to_cpu(entry->e_value_offs);
-			u32 size = le32_to_cpu(entry->e_value_size);
 			void *value;
 
 			/*
@@ -220,25 +225,36 @@ ext4_xattr_check_entries(struct ext4_xattr_entry *entry, void *end,
 }
 
 static inline int
-ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh)
+__ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh,
+			 const char *function, unsigned int line)
 {
-	int error;
+	int error = -EFSCORRUPTED;
 
 	if (buffer_verified(bh))
 		return 0;
 
 	if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
 	    BHDR(bh)->h_blocks != cpu_to_le32(1))
-		return -EFSCORRUPTED;
+		goto errout;
+	error = -EFSBADCRC;
 	if (!ext4_xattr_block_csum_verify(inode, bh))
-		return -EFSBADCRC;
+		goto errout;
 	error = ext4_xattr_check_entries(BFIRST(bh), bh->b_data + bh->b_size,
 					 bh->b_data);
-	if (!error)
+errout:
+	if (error)
+		__ext4_error_inode(inode, function, line, 0,
+				   "corrupted xattr block %llu",
+				   (unsigned long long) bh->b_blocknr);
+	else
 		set_buffer_verified(bh);
 	return error;
 }
 
+#define ext4_xattr_check_block(inode, bh) \
+	__ext4_xattr_check_block((inode), (bh),  __func__, __LINE__)
+
+
 static int
 __xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header,
 			 void *end, const char *function, unsigned int line)
@@ -260,18 +276,22 @@ errout:
 	__xattr_check_inode((inode), (header), (end), __func__, __LINE__)
 
 static int
-ext4_xattr_find_entry(struct ext4_xattr_entry **pentry, int name_index,
-		      const char *name, int sorted)
+xattr_find_entry(struct inode *inode, struct ext4_xattr_entry **pentry,
+		 void *end, int name_index, const char *name, int sorted)
 {
-	struct ext4_xattr_entry *entry;
+	struct ext4_xattr_entry *entry, *next;
 	size_t name_len;
 	int cmp = 1;
 
 	if (name == NULL)
 		return -EINVAL;
 	name_len = strlen(name);
-	entry = *pentry;
-	for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) {
+	for (entry = *pentry; !IS_LAST_ENTRY(entry); entry = next) {
+		next = EXT4_XATTR_NEXT(entry);
+		if ((void *) next >= end) {
+			EXT4_ERROR_INODE(inode, "corrupted xattr entries");
+			return -EFSCORRUPTED;
+		}
 		cmp = name_index - entry->e_name_index;
 		if (!cmp)
 			cmp = name_len - entry->e_name_len;
@@ -293,13 +313,13 @@ ext4_xattr_inode_hash(struct ext4_sb_info *sbi, const void *buffer, size_t size)
 static u64 ext4_xattr_inode_get_ref(struct inode *ea_inode)
 {
 	return ((u64)ea_inode->i_ctime.tv_sec << 32) |
-	       ((u32)ea_inode->i_version);
+		(u32) inode_peek_iversion_raw(ea_inode);
 }
 
 static void ext4_xattr_inode_set_ref(struct inode *ea_inode, u64 ref_count)
 {
 	ea_inode->i_ctime.tv_sec = (u32)(ref_count >> 32);
-	ea_inode->i_version = (u32)ref_count;
+	inode_set_iversion_raw(ea_inode, ref_count & 0xffffffff);
 }
 
 static u32 ext4_xattr_inode_get_hash(struct inode *ea_inode)
@@ -493,6 +513,7 @@ ext4_xattr_block_get(struct inode *inode, int name_index, const char *name,
 	struct buffer_head *bh = NULL;
 	struct ext4_xattr_entry *entry;
 	size_t size;
+	void *end;
 	int error;
 	struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
 
@@ -509,20 +530,20 @@ ext4_xattr_block_get(struct inode *inode, int name_index, const char *name,
 		goto cleanup;
 	ea_bdebug(bh, "b_count=%d, refcount=%d",
 		atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
-	if (ext4_xattr_check_block(inode, bh)) {
-		EXT4_ERROR_INODE(inode, "bad block %llu",
-				 EXT4_I(inode)->i_file_acl);
-		error = -EFSCORRUPTED;
+	error = ext4_xattr_check_block(inode, bh);
+	if (error)
 		goto cleanup;
-	}
 	ext4_xattr_block_cache_insert(ea_block_cache, bh);
 	entry = BFIRST(bh);
-	error = ext4_xattr_find_entry(&entry, name_index, name, 1);
+	end = bh->b_data + bh->b_size;
+	error = xattr_find_entry(inode, &entry, end, name_index, name, 1);
 	if (error)
 		goto cleanup;
 	size = le32_to_cpu(entry->e_value_size);
+	error = -ERANGE;
+	if (unlikely(size > EXT4_XATTR_SIZE_MAX))
+		goto cleanup;
 	if (buffer) {
-		error = -ERANGE;
 		if (size > buffer_size)
 			goto cleanup;
 		if (entry->e_value_inum) {
@@ -531,8 +552,12 @@ ext4_xattr_block_get(struct inode *inode, int name_index, const char *name,
 			if (error)
 				goto cleanup;
 		} else {
-			memcpy(buffer, bh->b_data +
-			       le16_to_cpu(entry->e_value_offs), size);
+			u16 offset = le16_to_cpu(entry->e_value_offs);
+			void *p = bh->b_data + offset;
+
+			if (unlikely(p + size > end))
+				goto cleanup;
+			memcpy(buffer, p, size);
 		}
 	}
 	error = size;
@@ -566,12 +591,14 @@ ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
 	if (error)
 		goto cleanup;
 	entry = IFIRST(header);
-	error = ext4_xattr_find_entry(&entry, name_index, name, 0);
+	error = xattr_find_entry(inode, &entry, end, name_index, name, 0);
 	if (error)
 		goto cleanup;
 	size = le32_to_cpu(entry->e_value_size);
+	error = -ERANGE;
+	if (unlikely(size > EXT4_XATTR_SIZE_MAX))
+		goto cleanup;
 	if (buffer) {
-		error = -ERANGE;
 		if (size > buffer_size)
 			goto cleanup;
 		if (entry->e_value_inum) {
@@ -580,8 +607,12 @@ ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
 			if (error)
 				goto cleanup;
 		} else {
-			memcpy(buffer, (void *)IFIRST(header) +
-			       le16_to_cpu(entry->e_value_offs), size);
+			u16 offset = le16_to_cpu(entry->e_value_offs);
+			void *p = (void *)IFIRST(header) + offset;
+
+			if (unlikely(p + size > end))
+				goto cleanup;
+			memcpy(buffer, p, size);
 		}
 	}
 	error = size;
@@ -674,12 +705,9 @@ ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
 		goto cleanup;
 	ea_bdebug(bh, "b_count=%d, refcount=%d",
 		atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
-	if (ext4_xattr_check_block(inode, bh)) {
-		EXT4_ERROR_INODE(inode, "bad block %llu",
-				 EXT4_I(inode)->i_file_acl);
-		error = -EFSCORRUPTED;
+	error = ext4_xattr_check_block(inode, bh);
+	if (error)
 		goto cleanup;
-	}
 	ext4_xattr_block_cache_insert(EA_BLOCK_CACHE(inode), bh);
 	error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer, buffer_size);
 
@@ -806,10 +834,9 @@ int ext4_get_inode_usage(struct inode *inode, qsize_t *usage)
 			goto out;
 		}
 
-		if (ext4_xattr_check_block(inode, bh)) {
-			ret = -EFSCORRUPTED;
+		ret = ext4_xattr_check_block(inode, bh);
+		if (ret)
 			goto out;
-		}
 
 		for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
 		     entry = EXT4_XATTR_NEXT(entry))
@@ -1791,19 +1818,16 @@ ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i,
 		ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
 			atomic_read(&(bs->bh->b_count)),
 			le32_to_cpu(BHDR(bs->bh)->h_refcount));
-		if (ext4_xattr_check_block(inode, bs->bh)) {
-			EXT4_ERROR_INODE(inode, "bad block %llu",
-					 EXT4_I(inode)->i_file_acl);
-			error = -EFSCORRUPTED;
+		error = ext4_xattr_check_block(inode, bs->bh);
+		if (error)
 			goto cleanup;
-		}
 		/* Find the named attribute. */
 		bs->s.base = BHDR(bs->bh);
 		bs->s.first = BFIRST(bs->bh);
 		bs->s.end = bs->bh->b_data + bs->bh->b_size;
 		bs->s.here = bs->s.first;
-		error = ext4_xattr_find_entry(&bs->s.here, i->name_index,
-					      i->name, 1);
+		error = xattr_find_entry(inode, &bs->s.here, bs->s.end,
+					 i->name_index, i->name, 1);
 		if (error && error != -ENODATA)
 			goto cleanup;
 		bs->s.not_found = error;
@@ -2162,8 +2186,8 @@ int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
 		if (error)
 			return error;
 		/* Find the named attribute. */
-		error = ext4_xattr_find_entry(&is->s.here, i->name_index,
-					      i->name, 0);
+		error = xattr_find_entry(inode, &is->s.here, is->s.end,
+					 i->name_index, i->name, 0);
 		if (error && error != -ENODATA)
 			return error;
 		is->s.not_found = error;
@@ -2719,13 +2743,9 @@ retry:
 		error = -EIO;
 		if (!bh)
 			goto cleanup;
-		if (ext4_xattr_check_block(inode, bh)) {
-			EXT4_ERROR_INODE(inode, "bad block %llu",
-					 EXT4_I(inode)->i_file_acl);
-			error = -EFSCORRUPTED;
-			brelse(bh);
+		error = ext4_xattr_check_block(inode, bh);
+		if (error)
 			goto cleanup;
-		}
 		base = BHDR(bh);
 		end = bh->b_data + bh->b_size;
 		min_offs = end - base;
@@ -2882,11 +2902,8 @@ int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode,
 			goto cleanup;
 		}
 		error = ext4_xattr_check_block(inode, bh);
-		if (error) {
-			EXT4_ERROR_INODE(inode, "bad block %llu (error %d)",
-					 EXT4_I(inode)->i_file_acl, error);
+		if (error)
 			goto cleanup;
-		}
 
 		if (ext4_has_feature_ea_inode(inode->i_sb)) {
 			for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);