Hi Greg, Sasha,
These were missing in 4.14-stable. Please apply to your queue.
80e46cf22ba0 ("btrfs: tree-checker: Enhance chunk checker to validate chunk profile")
005d67127fa9 ("btrfs: adjust return values of btrfs_inode_by_name")
6bf9e4bd6a27 ("btrfs: inode: Verify inode mode to avoid NULL pointer dereference")
The second one in only needed to make the backporting of third easier.
--
Regards
Sudip
>From 702a2b14382e0a063240d0bb7c93920d0130581e Mon Sep 17 00:00:00 2001
From: Qu Wenruo <wqu@xxxxxxxx>
Date: Wed, 13 Mar 2019 12:17:50 +0800
Subject: [PATCH 1/3] btrfs: tree-checker: Enhance chunk checker to validate chunk profile
commit 80e46cf22ba0bcb57b39c7c3b52961ab3a0fd5f2 upstream
Btrfs-progs already have a comprehensive type checker, to ensure there
is only 0 (SINGLE profile) or 1 (DUP/RAID0/1/5/6/10) bit set for chunk
profile bits.
Do the same work for kernel.
Reported-by: Yoon Jungyeon <jungyeon@xxxxxxxxxx>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=202765
Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx>
Reviewed-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
[sudip: manually backport and use btrfs_err instead of chunk_err]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
---
fs/btrfs/volumes.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 3d92feff249a..3b3c65b7d0c1 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6406,6 +6406,13 @@ static int btrfs_check_chunk_valid(struct btrfs_fs_info *fs_info,
return -EIO;
}
+ if (!is_power_of_2(type & BTRFS_BLOCK_GROUP_PROFILE_MASK) &&
+ (type & BTRFS_BLOCK_GROUP_PROFILE_MASK) != 0) {
+ btrfs_err(fs_info,
+ "invalid chunk profile flag: 0x%llx, expect 0 or 1 bit set",
+ type & BTRFS_BLOCK_GROUP_PROFILE_MASK);
+ return -EUCLEAN;
+ }
if ((type & BTRFS_BLOCK_GROUP_TYPE_MASK) == 0) {
btrfs_err(fs_info, "missing chunk type flag: 0x%llx", type);
return -EIO;
--
2.11.0
>From 30009193fdb6573aca0024b5819145cf854ce84c Mon Sep 17 00:00:00 2001
From: Su Yue <suy.fnst@xxxxxxxxxxxxxx>
Date: Mon, 5 Mar 2018 17:13:37 +0800
Subject: [PATCH 2/3] btrfs: adjust return values of btrfs_inode_by_name
commit 005d67127fa9dfb3382f2c9e918feed7a243a7fe upstream
Previously, btrfs_inode_by_name() returned 0 which left caller to check
objectid of location even location if the type was invalid.
Let btrfs_inode_by_name() return -EUCLEAN if a corrupted location of a
dir entry is found. Removal of label out_err also simplifies the
function.
Signed-off-by: Su Yue <suy.fnst@xxxxxxxxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
[ drop unlikely ]
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
---
fs/btrfs/inode.c | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index e985e820724e..1459010cfde5 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5585,7 +5585,8 @@ void btrfs_evict_inode(struct inode *inode)
/*
* this returns the key found in the dir entry in the location pointer.
- * If no dir entries were found, location->objectid is 0.
+ * If no dir entries were found, returns -ENOENT.
+ * If found a corrupted location in dir entry, returns -EUCLEAN.
*/
static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
struct btrfs_key *location)
@@ -5603,27 +5604,27 @@ static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(BTRFS_I(dir)),
name, namelen, 0);
- if (IS_ERR(di))
+ if (!di) {
+ ret = -ENOENT;
+ goto out;
+ }
+ if (IS_ERR(di)) {
ret = PTR_ERR(di);
-
- if (IS_ERR_OR_NULL(di))
- goto out_err;
+ goto out;
+ }
btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
if (location->type != BTRFS_INODE_ITEM_KEY &&
location->type != BTRFS_ROOT_ITEM_KEY) {
+ ret = -EUCLEAN;
btrfs_warn(root->fs_info,
"%s gets something invalid in DIR_ITEM (name %s, directory ino %llu, location(%llu %u %llu))",
__func__, name, btrfs_ino(BTRFS_I(dir)),
location->objectid, location->type, location->offset);
- goto out_err;
}
out:
btrfs_free_path(path);
return ret;
-out_err:
- location->objectid = 0;
- goto out;
}
/*
@@ -5924,9 +5925,6 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
if (ret < 0)
return ERR_PTR(ret);
- if (location.objectid == 0)
- return ERR_PTR(-ENOENT);
-
if (location.type == BTRFS_INODE_ITEM_KEY) {
inode = btrfs_iget(dir->i_sb, &location, root, NULL);
return inode;
--
2.11.0
>From 88e4d5edb73b1012ebee0b552c08e0ef793cfeb1 Mon Sep 17 00:00:00 2001
From: Qu Wenruo <wqu@xxxxxxxx>
Date: Wed, 13 Mar 2019 13:55:11 +0800
Subject: [PATCH 3/3] btrfs: inode: Verify inode mode to avoid NULL pointer dereference
commit 6bf9e4bd6a277840d3fe8c5d5d530a1fbd3db592 upstream
[BUG]
When accessing a file on a crafted image, btrfs can crash in block layer:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
PGD 136501067 P4D 136501067 PUD 124519067 PMD 0
CPU: 3 PID: 0 Comm: swapper/3 Not tainted 5.0.0-rc8-default #252
RIP: 0010:end_bio_extent_readpage+0x144/0x700
Call Trace:
<IRQ>
blk_update_request+0x8f/0x350
blk_mq_end_request+0x1a/0x120
blk_done_softirq+0x99/0xc0
__do_softirq+0xc7/0x467
irq_exit+0xd1/0xe0
call_function_single_interrupt+0xf/0x20
</IRQ>
RIP: 0010:default_idle+0x1e/0x170
[CAUSE]
The crafted image has a tricky corruption, the INODE_ITEM has a
different type against its parent dir:
item 20 key (268 INODE_ITEM 0) itemoff 2808 itemsize 160
generation 13 transid 13 size 1048576 nbytes 1048576
block group 0 mode 121644 links 1 uid 0 gid 0 rdev 0
sequence 9 flags 0x0(none)
This mode number 0120000 means it's a symlink.
But the dir item think it's still a regular file:
item 8 key (264 DIR_INDEX 5) itemoff 3707 itemsize 32
location key (268 INODE_ITEM 0) type FILE
transid 13 data_len 0 name_len 2
name: f4
item 40 key (264 DIR_ITEM 51821248) itemoff 1573 itemsize 32
location key (268 INODE_ITEM 0) type FILE
transid 13 data_len 0 name_len 2
name: f4
For symlink, we don't set BTRFS_I(inode)->io_tree.ops and leave it
empty, as symlink is only designed to have inlined extent, all handled
by tree block read. Thus no need to trigger btrfs_submit_bio_hook() for
inline file extent.
However end_bio_extent_readpage() expects tree->ops populated, as it's
reading regular data extent. This causes NULL pointer dereference.
[FIX]
This patch fixes the problem in two ways:
- Verify inode mode against its dir item when looking up inode
So in btrfs_lookup_dentry() if we find inode mode mismatch with dir
item, we error out so that corrupted inode will not be accessed.
- Verify inode mode when getting extent mapping
Only regular file should have regular or preallocated extent.
If we found regular/preallocated file extent for symlink or
the rest, we error out before submitting the read bio.
With this fix that crafted image can be rejected gracefully:
BTRFS critical (device loop0): inode mode mismatch with dir: inode mode=0121644 btrfs type=7 dir type=1
Reported-by: Yoon Jungyeon <jungyeon@xxxxxxxxxx>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=202763
Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx>
Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
[sudip: use original btrfs_inode_type()]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
---
fs/btrfs/inode.c | 41 +++++++++++++++++++++++++++++++++--------
fs/btrfs/tests/inode-tests.c | 1 +
2 files changed, 34 insertions(+), 8 deletions(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 1459010cfde5..c5ae2f4a7ec3 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5584,12 +5584,14 @@ void btrfs_evict_inode(struct inode *inode)
}
/*
- * this returns the key found in the dir entry in the location pointer.
+ * Return the key found in the dir entry in the location pointer, fill @type
+ * with BTRFS_FT_*, and return 0.
+ *
* If no dir entries were found, returns -ENOENT.
* If found a corrupted location in dir entry, returns -EUCLEAN.
*/
static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
- struct btrfs_key *location)
+ struct btrfs_key *location, u8 *type)
{
const char *name = dentry->d_name.name;
int namelen = dentry->d_name.len;
@@ -5622,6 +5624,8 @@ static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
__func__, name, btrfs_ino(BTRFS_I(dir)),
location->objectid, location->type, location->offset);
}
+ if (!ret)
+ *type = btrfs_dir_type(path->nodes[0], di);
out:
btrfs_free_path(path);
return ret;
@@ -5908,6 +5912,11 @@ static struct inode *new_simple_dir(struct super_block *s,
return inode;
}
+static inline u8 btrfs_inode_type(struct inode *inode)
+{
+ return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
+}
+
struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
{
struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
@@ -5915,18 +5924,31 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_root *sub_root = root;
struct btrfs_key location;
+ u8 di_type = 0;
int index;
int ret = 0;
if (dentry->d_name.len > BTRFS_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
- ret = btrfs_inode_by_name(dir, dentry, &location);
+ ret = btrfs_inode_by_name(dir, dentry, &location, &di_type);
if (ret < 0)
return ERR_PTR(ret);
if (location.type == BTRFS_INODE_ITEM_KEY) {
inode = btrfs_iget(dir->i_sb, &location, root, NULL);
+ if (IS_ERR(inode))
+ return inode;
+
+ /* Do extra check against inode mode with di_type */
+ if (btrfs_inode_type(inode) != di_type) {
+ btrfs_crit(fs_info,
+"inode mode mismatch with dir: inode mode=0%o btrfs type=%u dir type=%u",
+ inode->i_mode, btrfs_inode_type(inode),
+ di_type);
+ iput(inode);
+ return ERR_PTR(-EUCLEAN);
+ }
return inode;
}
@@ -6544,11 +6566,6 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
return ERR_PTR(ret);
}
-static inline u8 btrfs_inode_type(struct inode *inode)
-{
- return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
-}
-
/*
* utility function to add 'inode' into 'parent_inode' with
* a give name and a given sequence number.
@@ -7160,6 +7177,14 @@ struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
extent_start = found_key.offset;
if (found_type == BTRFS_FILE_EXTENT_REG ||
found_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ /* Only regular file could have regular/prealloc extent */
+ if (!S_ISREG(inode->vfs_inode.i_mode)) {
+ ret = -EUCLEAN;
+ btrfs_crit(fs_info,
+ "regular/prealloc extent found for non-regular inode %llu",
+ btrfs_ino(inode));
+ goto out;
+ }
extent_end = extent_start +
btrfs_file_extent_num_bytes(leaf, item);
diff --git a/fs/btrfs/tests/inode-tests.c b/fs/btrfs/tests/inode-tests.c
index 8c91d03cc82d..94b139e92ff3 100644
--- a/fs/btrfs/tests/inode-tests.c
+++ b/fs/btrfs/tests/inode-tests.c
@@ -245,6 +245,7 @@ static noinline int test_btrfs_get_extent(u32 sectorsize, u32 nodesize)
return ret;
}
+ inode->i_mode = S_IFREG;
BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
BTRFS_I(inode)->location.objectid = BTRFS_FIRST_FREE_OBJECTID;
BTRFS_I(inode)->location.offset = 0;
--
2.11.0
