The patch below does not apply to the 3.18-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 8e4b5eae5decd9dfe5a4ee369c22028f90ab4c44 Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso(a)mit.edu>
Date: Thu, 29 Mar 2018 21:56:09 -0400
Subject: [PATCH] ext4: fail ext4_iget for root directory if unallocated
If the root directory has an i_links_count of zero, then when the file
system is mounted, then when ext4_fill_super() notices the problem and
tries to call iput() the root directory in the error return path,
ext4_evict_inode() will try to free the inode on disk, before all of
the file system structures are set up, and this will result in an OOPS
caused by a NULL pointer dereference.
This issue has been assigned CVE-2018-1092.
https://bugzilla.kernel.org/show_bug.cgi?id=199179https://bugzilla.redhat.com/show_bug.cgi?id=1560777
Reported-by: Wen Xu <wen.xu(a)gatech.edu>
Signed-off-by: Theodore Ts'o <tytso(a)mit.edu>
Cc: stable(a)vger.kernel.org
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 435965598cb8..18aa2ef963ad 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4732,6 +4732,12 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
goto bad_inode;
raw_inode = ext4_raw_inode(&iloc);
+ if ((ino == EXT4_ROOT_INO) && (raw_inode->i_links_count == 0)) {
+ EXT4_ERROR_INODE(inode, "root inode unallocated");
+ ret = -EFSCORRUPTED;
+ goto bad_inode;
+ }
+
if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 54dd0e0a1b255f115f8647fc6fb93273251b01b9 Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso(a)mit.edu>
Date: Fri, 30 Mar 2018 20:04:11 -0400
Subject: [PATCH] ext4: add extra checks to ext4_xattr_block_get()
Add explicit checks in ext4_xattr_block_get() just in case the
e_value_offs and e_value_size fields in the the xattr block are
corrupted in memory after the buffer_verified bit is set on the xattr
block.
Signed-off-by: Theodore Ts'o <tytso(a)mit.edu>
Cc: stable(a)kernel.org
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 6304e81bfe6a..499cb4b1fbd2 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -197,7 +197,7 @@ ext4_xattr_check_entries(struct ext4_xattr_entry *entry, void *end,
while (!IS_LAST_ENTRY(entry)) {
u32 size = le32_to_cpu(entry->e_value_size);
- if (size > INT_MAX)
+ if (size > EXT4_XATTR_SIZE_MAX)
return -EFSCORRUPTED;
if (size != 0 && entry->e_value_inum == 0) {
@@ -540,8 +540,10 @@ ext4_xattr_block_get(struct inode *inode, int name_index, const char *name,
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) {
@@ -550,8 +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;
@@ -589,8 +595,10 @@ ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
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) {
@@ -599,8 +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;
diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h
index dd54c4f995c8..f39cad2abe2a 100644
--- a/fs/ext4/xattr.h
+++ b/fs/ext4/xattr.h
@@ -70,6 +70,17 @@ struct ext4_xattr_entry {
EXT4_I(inode)->i_extra_isize))
#define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1))
+/*
+ * XATTR_SIZE_MAX is currently 64k, but for the purposes of checking
+ * for file system consistency errors, we use a somewhat bigger value.
+ * This allows XATTR_SIZE_MAX to grow in the future, but by using this
+ * instead of INT_MAX for certain consistency checks, we don't need to
+ * worry about arithmetic overflows. (Actually XATTR_SIZE_MAX is
+ * defined in include/uapi/linux/limits.h, so changing it is going
+ * not going to be trivial....)
+ */
+#define EXT4_XATTR_SIZE_MAX (1 << 24)
+
/*
* The minimum size of EA value when you start storing it in an external inode
* size of block - size of header - size of 1 entry - 4 null bytes
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 54dd0e0a1b255f115f8647fc6fb93273251b01b9 Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso(a)mit.edu>
Date: Fri, 30 Mar 2018 20:04:11 -0400
Subject: [PATCH] ext4: add extra checks to ext4_xattr_block_get()
Add explicit checks in ext4_xattr_block_get() just in case the
e_value_offs and e_value_size fields in the the xattr block are
corrupted in memory after the buffer_verified bit is set on the xattr
block.
Signed-off-by: Theodore Ts'o <tytso(a)mit.edu>
Cc: stable(a)kernel.org
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 6304e81bfe6a..499cb4b1fbd2 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -197,7 +197,7 @@ ext4_xattr_check_entries(struct ext4_xattr_entry *entry, void *end,
while (!IS_LAST_ENTRY(entry)) {
u32 size = le32_to_cpu(entry->e_value_size);
- if (size > INT_MAX)
+ if (size > EXT4_XATTR_SIZE_MAX)
return -EFSCORRUPTED;
if (size != 0 && entry->e_value_inum == 0) {
@@ -540,8 +540,10 @@ ext4_xattr_block_get(struct inode *inode, int name_index, const char *name,
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) {
@@ -550,8 +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;
@@ -589,8 +595,10 @@ ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
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) {
@@ -599,8 +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;
diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h
index dd54c4f995c8..f39cad2abe2a 100644
--- a/fs/ext4/xattr.h
+++ b/fs/ext4/xattr.h
@@ -70,6 +70,17 @@ struct ext4_xattr_entry {
EXT4_I(inode)->i_extra_isize))
#define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1))
+/*
+ * XATTR_SIZE_MAX is currently 64k, but for the purposes of checking
+ * for file system consistency errors, we use a somewhat bigger value.
+ * This allows XATTR_SIZE_MAX to grow in the future, but by using this
+ * instead of INT_MAX for certain consistency checks, we don't need to
+ * worry about arithmetic overflows. (Actually XATTR_SIZE_MAX is
+ * defined in include/uapi/linux/limits.h, so changing it is going
+ * not going to be trivial....)
+ */
+#define EXT4_XATTR_SIZE_MAX (1 << 24)
+
/*
* The minimum size of EA value when you start storing it in an external inode
* size of block - size of header - size of 1 entry - 4 null bytes
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From a45403b51582a87872927a3e0fc0a389c26867f1 Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso(a)mit.edu>
Date: Thu, 29 Mar 2018 22:10:31 -0400
Subject: [PATCH] ext4: always initialize the crc32c checksum driver
The extended attribute code now uses the crc32c checksum for hashing
purposes, so we should just always always initialize it. We also want
to prevent NULL pointer dereferences if one of the metadata checksum
features is enabled after the file sytsem is originally mounted.
This issue has been assigned CVE-2018-1094.
https://bugzilla.kernel.org/show_bug.cgi?id=199183https://bugzilla.redhat.com/show_bug.cgi?id=1560788
Signed-off-by: Theodore Ts'o <tytso(a)mit.edu>
Cc: stable(a)vger.kernel.org
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 9d1da40c1f62..7cd022c344d1 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3492,15 +3492,12 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
}
/* Load the checksum driver */
- if (ext4_has_feature_metadata_csum(sb) ||
- ext4_has_feature_ea_inode(sb)) {
- sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
- if (IS_ERR(sbi->s_chksum_driver)) {
- ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
- ret = PTR_ERR(sbi->s_chksum_driver);
- sbi->s_chksum_driver = NULL;
- goto failed_mount;
- }
+ sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
+ if (IS_ERR(sbi->s_chksum_driver)) {
+ ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
+ ret = PTR_ERR(sbi->s_chksum_driver);
+ sbi->s_chksum_driver = NULL;
+ goto failed_mount;
}
/* Check superblock checksum */
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From a45403b51582a87872927a3e0fc0a389c26867f1 Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso(a)mit.edu>
Date: Thu, 29 Mar 2018 22:10:31 -0400
Subject: [PATCH] ext4: always initialize the crc32c checksum driver
The extended attribute code now uses the crc32c checksum for hashing
purposes, so we should just always always initialize it. We also want
to prevent NULL pointer dereferences if one of the metadata checksum
features is enabled after the file sytsem is originally mounted.
This issue has been assigned CVE-2018-1094.
https://bugzilla.kernel.org/show_bug.cgi?id=199183https://bugzilla.redhat.com/show_bug.cgi?id=1560788
Signed-off-by: Theodore Ts'o <tytso(a)mit.edu>
Cc: stable(a)vger.kernel.org
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 9d1da40c1f62..7cd022c344d1 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3492,15 +3492,12 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
}
/* Load the checksum driver */
- if (ext4_has_feature_metadata_csum(sb) ||
- ext4_has_feature_ea_inode(sb)) {
- sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
- if (IS_ERR(sbi->s_chksum_driver)) {
- ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
- ret = PTR_ERR(sbi->s_chksum_driver);
- sbi->s_chksum_driver = NULL;
- goto failed_mount;
- }
+ sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
+ if (IS_ERR(sbi->s_chksum_driver)) {
+ ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
+ ret = PTR_ERR(sbi->s_chksum_driver);
+ sbi->s_chksum_driver = NULL;
+ goto failed_mount;
}
/* Check superblock checksum */